Exercise Does A Brain Good

It Sharpens Thinking

Earlier this year, Dartmouth researchers added support to mounting evidence about the way that exercise affects learning and mental acuity: it boosts the production of “brain derived neurotrophic factor" -- or BDNF – a protein that is thought to help with mental acuity, learning and memory.

 

 

It May Alleviate Childhood ADHD Symptoms

In the same Dartmouth study, the researchers discovered that, thanks to the BDNF boost, exercise also helped to alleviate ADHD-like symptoms in juvenile rats. Since BDNF is involved in the brain's development and growth of new cells, the effect was more profound on the younger rats, with their still-developing brains and more rapid cell turnover, compared to adult rats. 

 

 

It Helps You Learn New Tricks

Even one exercise session can help you retain physical skills by enhancing what's commonly known as "muscle memory" or "motor memory," according to new research published in PlosOne.

As the New York Times reported, men who were taught to follow a complicated pattern on a computer and subsequently exercised were better able to remember the pattern in subsequent days than the men who didn't exercise after the initial squiggle test. 

 

It Supports Problem-Solving

In one study, mice that exercised by running not only generated new neurons, but those neurons lit up when the mice performed unfamiliar tasks like navigating a new environment

 

 

 

 

 

 

 

 

 

 

 

 

It Helps Alleviate Symptoms Of Depression

When you exercise, your pituitary gland releases endorphins to help mitigate the physical stress and pain you are experiencing. But those endorphins may play a more important and longer-lasting role: they could help alleviate symptoms of depression, according to a Mayo Clinic report

 

 

 

 

 

 

 

 

 

 

It Reduces Stress

Although exercising raises our levels of cortisol -- the hormone that causes physical stress and is even associated with long-term memory impairment -- its overall effect is one of a stress reducer. That's because exercise increases the body's threshold for cortisol, making you more inured to stressors. 

 

 

 

 

 

 

 

 

 

 

It Helps Delay Age-Associated Memory Loss

As we get older, an area of the brain called the hippocampus shrinks. That's why age is associated with memory loss across the board. However, profound memory loss -- such as in dementia and Alzheimer's disease patients -- is also contributed to by accelerated hippocampus shrinking. Luckily, the hippocampus is also an area of the brain that generate new neurons throughout a lifespan. And, the research shows, exercise promotes new neural growth in this area. 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Exercise Mental Benefits: How Workouts Boost Brain Power

We all know that regular exercise is a major player in our ability to achieve a healthy weight, a longer life expectancy and a reduced risk of chronic diseases -- from cancers to heart disease to diabetes. And, as you've likely discovered, it makes you look good too. But when you hit the gym, your biceps and lats aren't the only muscles you're working. Mounting research shows that aerobic activity may be one of the most important factors in maintaining a sharp brain.

 Just last week, a study revealed that exercise helped a group of men learn a new skill through enhanced "motor memory." But that's not the first or last word in the brawn-brain connection. Here are seven ways that getting your blood pumping is the best chance for gaining mental power too:

Foods With More Vitamin C Than An Orange

Papaya

One small papaya (about 157 grams) has 95.6 milligrams of vitamin C. A cup of mashed papaya has a whopping 140 milligrams.
More bang for your buck? Papaya is also high in vitamin A, folate and dietary fiber, according to Self Nutrition Data.

 

 

 

 

 

Red Bell Peppers

One cup of raw, chopped red bell pepper packs an impressive 190.3 milligrams of vitamin C. The same amount of a green pepper has 119.8 milligrams.

Broccoli

Need yet another healthy reason to eat your broccoli? Try this: One serving (148 grams) of chopped broccoli adds up to 132 milligrams of vitamin C.
 

Kale

Hungry for a salad? Try kale. Just two cups of this veggie, chopped, offers 160.8 milligrams of vitamin C. This superfood is also rich in vitamins A, C and K, as well as phytonutrients and fiber, according to WebMD.

Strawberries

Here's sweet news: one serving (147 grams) of strawberries has 86.5 milligrams of vitamin C. (And just this week, a study linked two servings of the red fruit a week to slowed cognitive degeneration.)

Kiwi

One serving of kiwi offers 137.2 milligrams of vitamin C.

 

 

Cauliflower

One small head of cauliflower (with a four-inch diameter) has 127.7 milligrams of vitamin C (and just 66 calories). 

 

 

 

 

 

 

 

 

 

 

 

 

 

Honorable Mention: Brussels Sprouts

They may not beat an orange, but a cup of Brussels sprouts still has a solid 48.4 milligrams of vitamin C. And the veggie is also rich in riboflavin, iron, magnesium, dietary fiber and vitamin A, among others.

 

 

Honorable Mention: Sweet Potatoes

Another orange food to add to the list (even though it doesn't have more C than an actual orange) are sweet potatoes. One large sweet potato has 35.3 milligrams.

 

 

Honorable Mention: Cantaloupe

Again, this one doesn't have quite as much vitamin C as an orange, but one serving does offer 49.2 milligrams.

 

 

 

 

 

 

 

Neck Cracking, Dangerous? Spinal Manipulation May Increase Risk Of Stroke

I crack my neck all the time. Is it really dangerous?
-- Laura 

If you crack your neck to relieve pain, you aren't alone. By one estimate, chiropractors perform between 18 and 38 million cervical spine manipulation treatments each year. That involves quick motions to loosen the joint and ligaments, which often makes a "pop" sound -- and that helps explain the colloquial term we often use: "cracking."

Cracking isn't just reserved for necks -- people commonly crack their knuckles, lower backs, hips, ankles and toes. Any joint can be "cracked," either by a professional or at home. Here at Healthy Living, several members of our team, along with readers who have written in, want to know if their own cracking is safe.

So what exactly is going on when a neck -- or really any joint area -- pops? Our joints contain fluid and gasses like nitrogen and carbon dioxide. When you put the liquid under pressure, as happens when force is applied to the joint, the gas exits, creating a pop sound, explained Dr. Stephen Perle, a chiropractor and Professor of Clinical Sciences at the University of Bridgeport. Interestingly, though we associate the pop with the dissipation of tension in the ligaments, they just coincide as a result of the movement -- they are unrelated.

Neck cracking was a subject of great interest when the British Medical Journal released commentaries from two sides of a debate: is neck manipulation worth the (admittedly) small risk of grave injury?
Although the practice, which is most popular among chiropractors (the commentary dealt specifically with professional manipulations) is not high risk, rare side effects include stroke brought on by a tear to the lining of the vertebral artery, which supplies blood to the brain. Does the risk outweigh the benefits? As might be expected, divisions within the medical community run along specialist lines. While many chiropractors think the manipulation is useful and safe, orthopedic surgeons are apt to disagree. Because the rate of injury is so low, the treatment looks safe from a public health perspective.
Arguing against neck manipulations in the BMJ, three clinical therapy professors pointed to studies that suggested neck manipulation was no more effective than other treatments, like exercising the muscles that support the spine, that are meant to alleviate the same pain. Given the association between neck cracking and stroke, however inconclusive, why risk it?

In contrast, arguing in favor of the treatment, epidemiologist Dr. David Cassidy of the University of Toronto and colleagues points to the tremendously low risk of stroke, and additional research that shows how neck manipulation can alleviate pain in ways that other treatments cannot. Perle, who is currently researching the relationship between cervical manipulation and stroke, agrees with Team Cassidy.

"We know that spinal manipulation causes stimulation of areas of the brain that block pain, changes the function of the muscles that help support the spine and changes the flexibility of motion segments in the spine," says Perle. "Exercises can help loosen the muscles and other treatments can help with pain, but the flexibility of the joint -- that's uniquely aided by manipulation."

But Dr. Michael R. Marks, an orthopedic surgeon who is a spokesperson for the American Association of Orthopedic Surgery, remains cautious. "When we talk about medical complications, they can be really small, say one percent," says Marks. "But if it happens to you, it's 100 percent."

He suggests that age may be a factor. "If you're a relatively young person, a spinal maniupation is relatively safe because you've got muscle strength, strength in the ligaments, bone strength. But as you age and your blood vessels get a little bit hard, you have some atherosclerosis -- because of the chiropractic manipulation -- you run the risk of artery eruption."

That's not the only age-related concern when it comes to a cervical spine manipulation, according to Marks. Older adults have more porous bones that are more prone to fracture. A quick, forceful motion is more likely to cause fracture in old bones than younger ones.

Luckily, one area where older adults do not need to worry when it comes to manipulations is arthritis. While it's a common myth that joint cracking can lead to arthritis later in life, research consistently shows that there is simply no association.

The bottom line is this: the odds of getting a debilitating injury -- either a vascular injury that results in stroke or a fracture or, a third rare option, nerve damage -- is very low, particularly if you have healthy, strong bones, ligaments and muscles. But do you want to take the chance? Maybe not. Just don't worry about arthritis -- there's no relationship at all.

Paleo Diet: Healthy Or A Hoax?

My health practitioner advised me to adopt this Paleo diet to reduce cholesterol and blood sugar. Also said it's an ideal way to lose weight. It recommends avoiding dairy, sugar, grains and legumes. Is this the answer to most of our health problems?
-- Rita

If you're unfamiliar with this popular diet, the Paleo Diet (also known as the "Caveman Diet") prescribes a pattern of eating that mirrors the way your ancestors ate back (way back!) in the day. The assertion is simple: diseases like obesity, diabetes and heart disease are illnesses "of civilization" and so, to combat the ill effects of the modern diet, we should return to a pre-civilization, hunter-gatherer diet of meat, fish, fruits and vegetables. That means all gains from the agrarian revolution -- grains, dairy, legumes, salt and sugars -- are off the menu.
"Although in theory this may seem like a sensible diet, particularly when removing sugar and salt, it has eliminated several food groups like dairy and grains, which provide essential nutrients, such as calcium, vitamin D, magnesium and phosphorus in dairy and B vitamins, fiber and antioxidants in grains," says Joy Dubost, a registered dietitian and a spokesperson for the Academy of Nutrition and Dietetics. "Legumes also provide a great protein source with little fat and lower in calories while providing essential nutrients and fiber."
Lisa Sassoon, a registered dietitian and assistant clinical professor of nutrition at NYU, agrees. "There's no real research behind it either. And it eliminates things that do have research behind them: grains, beans and low-fat dairy."

That research shows that nutrients in legumes, whole grains and dairy help to lower one's risk of osteoporosis and cardiovascular disease, reduce blood pressure, and maintain a healthy weight, according to Dubost.
And while the diet's restrictive nature might result in initial weight loss, it can be problematic as a long-term weight loss solution, according to the researchers we spoke with. When you eliminate whole food groups, you are bound to pay more attention to what you eat. And the ban on refined grains, salt and sugars means that processed foods are out. For those with a relatively processed diet, that will likely result in weight loss. And excess weight is one of the major associated conditions to high cholesterol, high blood pressure and pre-diabetes.
"If you lose weight, your cholesterol comes down. Weight loss will help all of those other things, with the exception of certain cases, where there’s a genetic predisposition," says Sassoon. In this way, Rita's doctor may be correct: if she currently eats a diet high in refined carbs, processed meals and sugar-laden treats, the Paleo Diet is certainly a step in the right direction.
But if she already has a diet full of fresh produce, lean proteins and whole foods, Paleo eating may not result in weight loss and may prevent healthy eating behaviors that come naturally. "If someone eats low-fat plain yogurt with berries for breakfast, that's not allowed on the diet," says Sassoon.
"The biggest issue to be addressed is not eliminating these food groups but ensuring that portion size is appropriate," explains Dubost.
There's also problematically little stated about saturated fat. As part of the Paleo diet, it would be easy to choose cuts of meat that are sky-high in artery-clogging LDL cholesterol and saturated fat. Especially for someone used to eating low-fat dairy protein, this switch would be harmful to cholesterol levels. And while the Paleo diet is high in fiber (thanks to all the fresh produce), forbidden foods like whole grain oats, beans and other grain and legume sources of fiber have been found to help moderate cholesterol levels.
There's another, wholly unrelated problem: pleasure. "It eliminates quinoa, ice cream, pasta -- these things we love to eat, that make us social creatures," says Sassoon. "And that means we're less likely to stick with it, more likely to binge. It's not just about losing weight, it’s also about learning how to enjoy food in a healthy way."
So does the Paleo Diet really lower cholesterol and help with many of the conditions that lead to metabolic syndrome? Only insofar as they cut out sugary, fatty and processed foods. Buy you can do that without eliminating whole food groups or imitating the eating patterns -- most likely dictated by food scarcity -- of pre-agrarian ancestors.

Is Organic Food Healthier?

Is that Stanford study right? Is organic food really no healthier?

Last week, Stanford University researchers published a study in the Annals of Internal Medicine that they said showed organically-grown food to be no more nutritious than conventionally-grown food. Chaos ensued, as consumer advocacy groups, fellow researchers and environmental and parenting organizations condemned the study, suggested financial ties to food giant Cargill motivated it and even filed a petition to have the research retracted from its journal
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As of publication, a petition with Change.org had 3,351 signatures, on the grounds that it didn't factor in the potential health consequences of genetically modified foods, high fructose corn syrup and other additives that are found more often in conventional foods than in organic ones. As Rosie Mestel wrote in the Los Angeles Times:

The scientists weren’t studying genetically modified foods (though if GMO foods were in the conventional data, one might think that GMO-caused health factors would have revealed themselves in the results). And they weren’t studying high-fructose corn syrup -- they were only reviewing fruits, vegetables, eggs, grains, dairy, poultry and meat. Not processed foods.

The article, in other words, wasn’t about the entirety of everything that people think is wrong about the way our food is grown and produced today. It wasn’t even about every type of difference between organic and conventionally grown food.

Alarmists were not the only ones sounding the alarm, so to speak. As HuffPost's Lynne Peeples reported, a researcher who published a similar analysis in 2011, Kirsten Brandt of Newcastle University, had several criticisms. During the course of her research, she discovered that organic food was indeed nutritionally distinct from conventionally grown food.

"The choices they made don't seem to make sense -- they seemed to include ones where the difference was smallest to begin with," Brandt told Peeples. "I'd like to know why they chose these and not others that were just as well-described in the same papers they included."

As for the study itself, what were they actually trying to prove?

Researchers Dr. Dena Bravata, of the Center for Health Policy, and Dr. Crystal Smith-Spangler, an instructor for Stanford's Division of General Medical Disciplines, conducted an analysis of the 17 most relevant studies that compared the health of subjects who ate either organically or conventionally grown food over periods as short as two days and as long as two years. They also looked at 223 studies that compared organic and conventional foods in terms of levels of various nutrients, as well as bacterial, fungal and pesticide contamination.

They found very little difference between the composite nutrient profiles of organic and non-organic foods. And while they found that conventionally raised pigs and chicken were more likely to yield meat that was contaminated with antibiotic-resistant microbes, the overall microbial levels on organically and conventionally-grown foods were similar.

They did find two studies that showed how children who ate conventional produce had higher pesticide levels in urine samples than those who ate organic foods.

"There isn't much difference between organic and conventional foods, if you're an adult and making a decision based solely on your health," Bravata said in a statement about her study's results. Smith-Spangler added that she was surprised by the results.

Given that similar analyses have found different results, it makes sense to take all of these studies with a grain of salt. While we might not yet know the health impact of the differences between organic and non-organic foods, we have plenty of information to make a personal decision in the supermarket aisle that extend beyond nutrients.

Avoiding pesticides and antibiotic-resistant infections are two good reasons to eat organic food, but they aren't the only ones: some believe that organically-raised animals are also more humanely raised and evidence shows that organic farming is the more environmentally-friendly option. And given the lack of longitudinal study, it's impossible to know what long-term health outcomes both of these options would have.

How A Hangover Works

"What actually causes hangovers? If alcohol is metabolized after a few hours, why do I still feel crummy the next day?"
-- Alana

If the data is any indication, at least 75 percent of you will recognize this feeling: a throbbing headache, exhaustion, queasiness and even muscle fatigue following a night of overindulging. But what is it about drinking alcohol that causes such discomfort?
The cause is a combination of factors, but primarily one: dehydration.
"Alcohol is a diuretic, so you end up losing water. And the dehydration effect is probably the most severe contributor to hangover," says Dr. Gary Murray, the program director for the Division of Metabolism and Health Effects of the National Institute on Alcohol Abuse and Alcoholism.

The more you drink and the higher the concentration of alcohol in the drinks you choose, the more dehydrated you're going to be. According to an overview of the research, that's because alcohol suppresses the release of the hormone vasopressin, which normally repurposes water released by the kidneys back into the body. With the absence of vasopressin, that water is marked for the bladder and eliminated. Alcohol also causes inflammation of the stomach lining, which can cause diarrhea -- another dehydrating condition.
In the morning, that translates to classic dehydration symptoms: a headache as the body borrows water from the brain, causing temporary tissue shrinkage; thirst; dry mouth; nausea; and even dizziness.
Though dehydration is a major factor, it's not the only one. Everyone has a unique physiological response to alcohol in terms of how it's broken down and eliminated by the body. And the way you metabolize alcohol can certainly have an effect on the onset, severity and duration of a hangover.
Alcohol is metabolized in two stages: one group of enzymes break down ethanol -- the alcohol that you ingest -- into acetaldehyde. Acetaldehyde is a toxic, carcinogenic substance, but soon after a second class of enzymes metabolizes the acetaldehyde into harmless acetate, which is basically vinegar. The problem is that for some people, the second metabolic process can be slower and less effective than in others. That means a build-up of acetaldehyde toxicity, which includes several hangover-like symptoms like rapid pulse, sweating, skin flushing, nausea and vomiting.
Interestingly, there are some ethnic patterns to this variation: Asians, Asian-Americans and Native Americans have a higher instance of a gene that causes inactivity of the enzyme aldehyde dehydrogenase-2 which, along with glutathione, metabolizes acetaldehyde into acetate, according to National Institutes of Health research.
"People with that hypersensitivity to alcohol know it," says Jim Schaefer, a research professor of anthropology at Union College and an expert on alcohol metabolism. "They'll feel a flushing response, they'll feel nauseous after one or two drinks. It's not just during the hangover."
"Whether they choose to ignore that [feeling] has more to do with social factors," he added.
Another contributor to hangovers has to do with the taste of alcohol: congeners. These are byproducts of the distillation and fermentation process that are both good and bad -- while they give alcohol, especially amber alcohols like whiskey and rum, their distinct, full flavor, they're also associated with feeling ill the next day.
"A quadruple distilled vodka is very clean compared to a heavy dark rum and it's probably going to make you feel less sick," says Schaefer.
Let's say you've overdone it. What's the next step? Short of the recommendation to drink in moderation (or not at all), drinking a preemptive glass of water alongside your cocktail or before bed is the best preventive measure, according to all the experts who spoke to Healthy Living. Everyone seems to have their own hangover cure -- either commercial or homegrown -- but what does the research actually show?
"My own personal experience with hangovers -- and I've had a couple -- is that a tall glass of water and an hour of time after I wake up and I'm usually OK," says Murray. "Other people who sell hangover cures or tout things like 'hair of the dog' -- those things are probably less useful. You probably don't need to add a lot beyond water."
Given that dehydration is accompanied by electrolyte imbalance from the loss of sodium and potassium (which might help explain those salty breakfast cravings), rebalancing with a sports drink or alternative might be a good idea. And, for a pounding headache, aspirin or ibuprofen -- rather than acetaminophen, which can cause liver damage, especially in conjunction with alcohol -- can help.
Additionally, Schaefer believes that some commercial treatments that involve activated charcoal have a role in treating and preventing hangovers.
"The charcoal is a very fine compound that filters alcohol compounds -- grabbing them out of the system, shunting them into the lower parts of the small intestine. In a way, activated charcoal acts much like the charcoal slurry given to poison victims in the ER," he says. But other experts are skeptical that the charcoal can effectively target alcohol and its byproducts in a person's system.
It's important to remember that the best way to prevent a hangover is not to drink in the first place -- and to drink moderately if you choose to. If you believe that you or someone you know is abusing alcohol or suffering from alcohol addiction or dependency, there are many resources available such as these provided by the U.S. Centers for Disease Control and Prevention.

Why Do My Eyelids Twitch?

Why does your eyelid go through twitching phases?
-- Anya

Myokymia, or involuntary eye twitching, is a condition that many of us are familiar with. And it seems everyone has an opinion on what triggers it: Is it fatigue? Eye-strain? Stress?

"Most of the time, myokymia is idiopathic, which is a fancy way of saying we have no idea why it happens," says Dr. Andrea Thau, an associate clinical professor at SUNY Optometry and a spokesperson for the American Optometric Association. "It’s such a benign condition, and tends to resolve on its own, so there's little incentive to research it."

Essentially, myokymia is a twitch -- an involuntary muscle spasm in the upper eyelid muscle that causes a fluttery sensation. The trick to stopping it, according to Thau, is to "break the twitch." She recommends trying alternating hot and cold compresses, which can soothe the overactive nerve that's causing the spasm. If that doesn't work, "try drinking a glass of tonic water," she recommends. "The quinine helps nerve impulses."

Some doctors will prescribe antihistamines for particularly stubborn or enduring eye twitches. If eyes are a bit swollen -- due to low-grade allergic reaction -- that can cause the nervous system to overreact and trigger a twitch.

Huffpost Wellness Editor Patricia Fitzgerald has observed clinically -- which is to say, in an observational, rather than a scientifically rigorous research setting -- that patients of hers have mentioned fatigue and stress in connection to eyelid twitching. Fitzgerald finds that many of her patients' twitches are resolved by acupuncture.

In very rare instances, eyelid twitching can indicate a more serious condition, like the beginning stages of multiple sclerosis or a lesion on the brain stem. Those conditions typically begin with a host of symptoms, and in this circumstance the eyelid twitch soon moves to the facial muscles, as well. It's so rare, in fact, that Thau says she's never seen it in clinic herself.

There is another condition that affects the eyelid muscles, a rare disorder called blepharospasm, in which the eyelids involuntarily close. This can take the form of brief, excessive blinking or squinting and can progress to full eye closure, according to Mary Smith of the Benign Essential Blepharospasm Research Foundation. Blepharospasm affects about 60,000 Americans, and is more likely to affect women and those over 40, Smith says. "It can be problematic, if you don’t know when your eyes are going to shut, you may walk into things or fall," she says. "It’s definitely debilitating."

There's a genetic component to blepharospasm and also a trigger -- sometimes trauma, a secondary condition like dry eye or even external factors like bright or rapidly changing lights. It is most commonly treated with regular Botox injections and, interestingly, blepharospasm was among the conditions listed during Botox's first FDA approval in 1988, according to Smith.

If you experience occasional eye twitches, chances are it's a benign. But it's important to get your eyes checked each year by an ophthalmologist or doctor of optometry to rule out any other problems. Even if it's simply eye strain or stress causing the twitch, it could indicate a need for glasses.

Adult Acne: Why Does It Happen?

I'm a 61-year-old woman who has hardly had a pimple my whole life, til now. Lately, I've been getting these huge, what I call, under-grounders. They hurt like the dickens but never come to a head. They appear around my mouth, near my nose or on my forehead. What is going on?
-- Jane 

A pimple occurs when sebum -- the lubricant that naturally moisturizes our skin and hair -- is trapped under dead skin cells and debris in a hair follicle, according to the Mayo Clinic. Typically, sebum rises to the surface, where it is able to condition the skin. If it gets trapped, it creates an ideal circumstance for bacteria to grow. What Jane calls "under-grounders" are actually pockets of sebum and bacteria that are trapped further down along the hair shaft, deep within the follicle.

Adult acne is common -- about 30 percent of women and 20 percent of men between the ages of 20 and 60 have breakouts, according to WebMD. So why would a person develop acne later in life? Very often, it's related to hormones.

"When adult women experience acne outbreaks, hormones are usually the primary culprit," dermatologist Dr. Diane S. Berson said in an interview with Medical News Daily. "Hormonal acne can be particularly frustrating because it may not respond to the same over-the-counter treatments that worked for some women during their teenage years."

At 61, menopause, hormonal treatments or a growing ratio of androgen (male) hormones like testosterone may be contributing to the sudden emergence of acne, according to an explainer by the American Academy of Dermatology. Research shows that testosterone, for example, causes increased production of sebum by the sebaceous gland.

Other causes of adult acne can be medication related -- some psychotropic medications, like lithium, or steroids or hormonal medications can contribute to acne breakouts, according to the Mayo Clinic.
The best course of action may be to talk to a doctor about having your hormone levels checked and to speak with a dermatologist about proper skincare. Since many acne medications and special soaps are geared towards teenage skin, which is thicker and less dry, picking the right skin care regimen for an adult requires greater care.

Who Decides Serving Sizes?

How do they decide what a serving size is?
-- Gina

Believe it or not, we decide what a serving size is. The unit we see at the top of our nutrition labels (eight cookies, 100 grams, half a bottle, e.g.) comes from the average amount that Americans over the age of four consume in a single seating. And that average comes from federal food surveys. When nutrition labeling on packages became standardized in 1994, a U.S. Department of Agriculture task force used answers from the two previous Nationwide Health and Nutrition Examination Survey (known as the NHANES) to determine how much a typical person eats at one time. These averaged amounts are known within the industry as "reference amounts customarily consumed per eating occasion."
In other words, the current serving size on your bag of chips is a reflection of your fellow citizens' eating habits -- as they were between 1978 and 1988, when the two NHANES data were released.
But let's back up for a moment and discuss what a serving size actually is -- and is not. A serving size is a measurement that allows food manufacturers to create accurate and uniform nutrition labels across brands. It is not a prescriptive size that relates to health. "You’ve got servings related to the nutrition facts panel and then another issue is a reasonable portion of food to build a healthy eating pattern," says Dr. Robert Post, executive director of the USDA's Center for Nutrition Policy and Promotion. "That may be a little bit different. The serving size might be bigger than what we’d use in the nutrition world to promote good habits."

Instead, Post -- who previously worked for the task force that helped determine serving size -- recommends ignoring that measure when determining a reasonable portion size. "It's really an industry regulation tool," he tells HuffPost Healthy Living.
Serving sizes are also occasionally unrealistic. For example, a serving size of potato chips is ten chips. But when a family size bag is opened, we all know what happens -- half the bag disappears.
At this point you may be wondering what we starting wondering as we spoke to Post and investigated the industrial regulations on the U.S. Food and Drug Administration's website. What about foods that have been created since the labeling regulations were put in place? When a manufacturer wants to bring a new food to market, they must classify their food -- say, a "snacking cracker" (as opposed to a non-snacking cracker, a category that includes ice cream cones) -- and then look up the reference amount on a large database. The FDA and USDA share regulation, splitting jurisdiction by food group. The FDA, for example, is responsible for ensuring serving size accuracy for things like bread and yogurt; the USDA regulates things like meat, poultry and some egg products.
Of course, most of us do not have a new and innovative food to label -- we simply want to know how much snacking we can do to maintain a healthful diet. In that instance, you may be better off talking to a nutritionist or looking at the USDA's MyPlate guidelines. But it's always good to know where your health information comes from -- and it's a major advance for healthy eating that we have a tool through which we can equally measure different brands and versions of the same products.

Eat Before A Workout: Is It Necessary?

Honestly, when working out first thing in the morning, do I really need to eat before? Especially if I'm just doing a quick 30-minute run or elliptical?
-- Alicia, 26, Shreveport, Louisiana

With all of the marketing of sports drinks, bars, gels and powders, this is an excellent question to ask. There's certainly no harm in eating -- and it might help you meet your fitness goals by giving you more energy during the actual run or elliptical workout.
"It's a contradiction, but you really do need the calories to perform well," Barbara Lewin, R.D., L.D., a sports nutritionist who works with professional and Olympic athletes, said in an earlier interview about sports drink alternatives. "The calories are what's enabling you to work out at your best. If you're not well-fueled, you're not going to work out as hard."
And certainly, if you're planning an endurance training session, you must eat. According to Andrea Hacker Thompson, M.S., R.D., of the American College of Sports Medicine, endurance athletes should eat even when they aren't hungry. She wrote:

A race car never starts a race without new tires and a full tank of gas, so an endurance athlete should not start a workout without fueling. Eating before a workout guarantees that the body starts with a full tank of glycogen.

But even for those of us who aren't trying to run an ultramarathon, if we plan a rigorous session of 90 minutes or longer, getting a bit to eat beforehand is a good idea. To understand why, it's important to know how our bodies use energy during a workout. When we exert ourselves, we burn glycogen -- the cache of glucose we keep stored in our muscle and liver cells. After we've gone through that store of carbohydrates, we can start to feel fatigued. As Thompson explains for the ACSM, the body can store about 2,000 calories in glycogen. If you plan to go over that amount (and, wow, that's quite a workout if you do!), you could begin to get light-headed, weak or just plain exhausted.
But for a 30 minute treadmill session? You probably don't have to make a concerted effort to eat enough. You do, on the other hand, have to keep hydrated. Water is fine for a half-hour run, but any workout over an hour may require some electrolyte replacement -- such as a sports drink or a piece of fruit.
Beyond the question of whether or not to eat, there are other considerations. It's important not to eat too much -- or too little. And to know when to eat it. The Mayo Clinic provides a guideline, suggesting a small snack about an hour before exercising or a medium meal two hours before a gym session. For a full meal, they recommend giving yourself a three to four hour time period between eating and hitting the gym. Overdo it, and you could give yourself stomach cramps or even diarrhea.
Most of all, it's important to note your own reaction to food and figure out an eating plan that's right for you. Feel fine during a morning run, even without that yogurt? Skip it. But if you need a little something for extra energy, there's nothing wrong with starting with a snack.

Losing The Last 10 Pounds: Why Does Weight Loss Get Harder?

"Why is it so hard to lose the last 10 pounds? And why is it harder to lose weight the smaller I get?"
-- Tamara

Anyone who has tried to lose weight knows about those frustratingly immobile final five or 10 pounds. And while there are a lot of suggestions (just Google "last 10 pounds" and you'll enter an echo-chamber of weight loss advice, scientific half-truths and can-do enthusiasm), the truth is that several pretty straight-forward reasons can explain that unshakeable weight.
The first is easy to fix, but also the most psychologically daunting: it could be something called "diet fatigue," in which the repetitive behaviors dieting requires -- keeping a food journal, weighing portion sizes, skipping that glass of wine -- become arduous, hard to manage and, frankly, boring.
"Dieters become less careful, they are not taking the precautions they did in terms of knowing what they ate, how much," says Carla Wolper, Ed.D., R,D., research faculty at the Obesity Research Center at St. Luke’s and assistant professor in the Department of Psychiatry at Columbia Medical Center. "They may not realize they’re not as careful anymore."

That's not an invitation for blame -- it can happen insidiously and there's an easy solution. If the scale needle slows its descent, simply write what you eat down in a food journal. "Keeping food records is always recommended," says Wolper. "Studies show that people will lose weight, even if they don’t do anything different to their diet but simply start writing it down."
There is also the possibility that it's time to recalculate. When a person begins to lose weight, their metabolic rate drops. In other words, they need fewer calories to meet basic functioning and requirements. While a 150-pound woman might have a certain basic metabolic rate, that rate may drop when she becomes a 130-pound woman. That's why it's a good idea to reevaluate caloric needs after more than 10 pounds of weight loss, according to Wolper.
"People who are normal weight tend to eat fewer calories than people who are overweight, every day, forever," agrees Rebecca E. Lee, director of the Texas Obesity Research Center and a professor of nutrition in the Department of Health and Human Performance at the University of Houston. "It takes fewer calories to maintain a lower body weight. This doesn't necessarily mean that they eat less volume -- they might, but they also might eat more nutrient dense foods that have fewer calories, like vegetables, fruits, lean meats, etc."
There's an additional consideration regarding metabolism: something called "metabolic adaptation."
"When dieting, your body is forced to work on a reduced number of calories per day. Eventually your body adapts and trains itself to live on whatever calories it gets -- without losing weight. This built-in survival mechanism is your body’s way to protect you against starvation," says Dr. Caroline J. Cederquist, a metabolic expert and board-certified medical weight management specialists. "Once you have hit this point, you may manage to lose a few bonus pounds, but they will come off much more slowly and, before you know it, the weight you lost may start to come back on!"
So what can you do? Interestingly, the answer is not exercise. (Which is not to say you shouldn't exercise. Please exercise!) Very often we're told that building muscle mass will help rev up our metabolisms because muscle tissue burns more calories per hour than fat tissue does. But, as Wolper explains, the difference in caloric burn rate is minor. Fat tissue burns about two calories per pound per day, while muscle tissue of the same weight burns seven calories per day. If someone made a significant change -- transformed two pounds of fat into two pounds of muscle, that would amount to a difference of 10 more calories burned per day.
"The truth is that skeletal muscle doesn’t burn that much more than fat. Our brains burn the most calories. In fact, the lean tissue that burns a lot of calories is our heart, lungs, liver and brain. About 60 percent of the calories that are burned come from those four sources," says Wolper.
Exercise may help create a greater calorie deficit and that will help further along weight loss or help maintain sustained weight loss -- but it won't make a big metabolic difference.
Instead, in addition to redoubling food journal efforts and recalculating caloric intake for one's new size, Cederquist recommends something she calls a "metabolic adjustment phase." Instead of reducing calories, she suggests a two-week period of increased meal sizes. "During this phase, the goal is not to lose weight, but to readjust your body’s ability to metabolize an increasing number of calories, by increasing portion sizes and bumping up caloric intake."
Most of all, it's important to evaluate one's goals. Have you reached a healthy weight? If so and if continued weight loss is a huge struggle, it may be time to consider entering a maintenance phase. "Focus on the benefits of maintaining your weight loss," says Cederquist. "And remember that maintaining is as important as losing."

Cardio Or Weights First? Exercise Order Sometimes Matters

"Is there an order to working out? In other words, should I do weights first and then cardio?"
-- Karen 

Working out is always good for you. The good news is that, whether you do it before or after weight training, cardiovascular exercise like running, swimming, biking or machine-work will improve everything from your heart health to your mood to your chance of avoiding many cancers. And lifting weights helps with everything from bone density to metabolism.
But according to exercise physiologists and personal trainers we spoke with, the order of operation can change depending on a person's goal.
"This question is one of the biggest questions on people's minds when they go to the gym," says personal trainer and HuffPost blogger Jeff Halevy. For those who are seeking weight loss, cardio should come first, but if gaining muscle mass is the goal, it's time to hit the weight room first. But why?

Let's start with the muscle-building scenario. "Doing cardio first will induce fatigue that may compromise technique and possibly increase risk of injury," explains Fabio Comana, director of Continuing Education for the National Academy of Sports Medicine. Exhausting oneself with a big run right before weights and resistance training doesn't just up the risk of injury, it also means you'll have less energy to throw into a really good weight training session.
On the other hand, if you're looking to lose fat, Halevy recommends doing interval cardio training before getting started on weights. As he explains, the cardio will deplete your body's supply of glycogen -- the stored form of glucose in muscle cells and a primary material in our energy storage. Once glycogen is depleted, the body turns to more long-term storage sources, like fat.
"If your goal is strictly a lean body -- not to be strongest, or most powerful, but achieve maximal leanness -- I always recommend implementing high-intensity interval training at the beginning of each workout," says Halevy.
But that doesn't mean weights aren't important for fat loss. In fact, when it comes to analyzing the percentage weight loss that's comprised of fat versus lean tissue like muscle, weights have cardio beat overall.
"Resistance training should always be a consideration," explains Comana in an email. "Mother nature will help us lose lean tissue naturally (23 percent in women between ages 30 and 70), that we need to preserve. Diet and cardio also results in lean tissue losses (68 percent fat, 22 percent muscle / lean tissue). Whereas diet and resistance leads to 97 percent fat loss, and only 3 percent lean tissue loss."
There may be other reasons for doing cardio first. As Comana points out, many more people are familiar with cardiovascular exercise, so it will seem less intimidating and is thus more likely to happen. If the weight room is daunting enough to prevent a workout session, it's worth getting started on cardio and working your way up. And if another health goal -- say Type 2 diabetes or hypertension prevention or treatment -- is the priority, Comana recommends cardio over resistance. "Some diseases are better managed with cardio first, then introducing resistance training later," he told Healthy Living.
It's important to get the opinion of a doctor and certified personal trainer or exercise professional before proceeding, but the takeaway is simple: if you're exercising, no matter the order, you aren't doing anything wrong. Depending on your goal, you may want to choose one type of exercise over the other. Of course, you could alternate days and avoid the question entirely.

Should You Take A Multivitamin?

Is there a daily multivitamin that you would recommend to help boost energy for exercise?
-- Johnny, 23, East Bay, CA.

There are actually two parts to this question. The first is silent: should healthy adults be taking a daily multivitamin at all? If you believe the latest research, the answer is no.

The first thing to acknowledge is that, for the most part, Americans are not deficient in vitamins. A recent CDC survey found that we're sufficiently nourished in essential nutrients like vitamins A, D and folate. But just because we aren't deficient, doesn't necessarily mean that our vitamin levels are optimal. The question is, how important are optimal levels?

"You get your nutrients through your food. Through the milenia, that’s what the case was and we survived as a species -- in fact, we thrived," says Alice Lichtenstein, DSc, senior scientist and director of the Cardiovascular Nutrition Laboratory at the Jean Mayer U.S. Department of Agriculture (USDA) Human Nutrition Research Center on Aging at Tufts University and the author of a position paper on the usefulness of multivitamins. "To assume that we suddenly have lost this ability doesn't quite make sense."

While whole foods are a good source of nutrients, many public health researchers actually credit processed, packaged foods that have been fortified with vitamins for the nutrient-rich American diet. "Most people, if they are eating a generally healthy diet -- not a perfect diet, but a generally healthy diet, don't need a multivitamin," says Katherine Zeratsky, a registered dietician at the Mayo Clinic. "With things like breakfast cereals, nutrition bars, foritified grains and bread, because all those foods are fortified with other minerals, we are getting more than we realize and more than we need."

That doesn't make a multivitamin just redundant, it could make it dangerous: Lichtenstein points out to Healthy Living that a large surplus of supplemental folate may have an adverse effect on colon cancer and other research has found a relationship between folic acid supplements and prostate and breast cancers as well. Lichtenstein adds that an overabundance of vitamin A, to levels of toxicity, can manifest in accelerated bone loss.

Some vitamins are water-soluble and others are fat-soluble, explains Zeratsky. While water-soluble vitamins will pass right through the body and are expelled in urine (the inspiration for the popular "expensive urine" quip among physicians), fat-soluble vitamins are stored and build up over time, making it a bit easier to reach toxicity. Fat-soluble vitamins include D, E and A -- common inclusions in both fortified foods and in multivitamins.

What's more, a longitudinal study of women who took multivitamins and those who did not found that taking a regular multivitamin was actually associated with a shorter overall life expectancy. Critics of the study suggested that a bias may exist -- namely, that people who take a multivitamin may be doing so in response to overall health problems that reduce their life spans.

Although, according to Lichtenstein, the profile of the average multivitamin user is this: a middle-aged woman who eats healthfully and exercises and has an above-average education level. “The population who takes them is most often the population who is least likely to need them,” she says.

But there are people who can benefit from a multivitamin or certain supplements. One example that all of the experts we spoke with gave was women of child-bearing age -- and especially those trying to get pregnant -- who should ensure that they get enough folate to prevent birth defects like spina-bifida. Additionally, women who are going through or have gone through menopause might need a boost in certain nutrients, and those on specialized diets that are lacking in nutrition might also benefit. Because it’s so highly individualized, a supplement regime should be planned with a doctor.

Still, there remains no evidence that multivitamins are useful to overall or long-term health -- and some, albeit inconclusive evidence that they are harmful.

If you are going to take a multivitamin, Zeratsky says that she doesn't believe it will hurt. To ensure purity, she recommends looking for a brand that has been certified by a third party testing agency, like U.S. Pharmacopeal. Since vitamins and supplements are not regulated at the same level as food, it's important to know the source of what you're taking.

But long-term health isn't the primary concern at the center of this question. Johnny asked if there was a particular multivitamin associated with energy. Some people report, in a clinical setting (as opposed to a significant study) that the family of B vitamins gives them extra energy, reports Zaretsky. Though B vitamins are prevalent enough in our diet to maintain basic levels, it's possible that people who have an energy response to B vitamins may be low in these nutrients without being deficient. The extra boost may also increase energy, as the vitamins play a role in regulating metabolism.

Beyond that, when it comes to exercise, important vitamins for energy, muscle function, recovery and bone strength include vitamin D, vitamin C and electrolytes like potassium and sodium. Calcium is also really important -- not only for bone health, but for regulating how our muscles contract, according to Zaretsky.
That said, it's better to get these nutrients from sunlight (in the case of the hormone, vitamin D) and whole foods. "Our healthy diet goes so far beyond what a pill can offer -- known and unknown," says Zaretsky, pointing to the fiber and phytonutrients that foods contain and pills lack.

Agrees Lichtenstein: "The data generally supports better outcomes who are eating well-balanced diet. It's not particularly exciting, but from the perspective of what we can support in the research, that’s the best information we have."

What Is Metabolism: How Long After I Eat Is Weight Added To My Body?

"How long does it take for the food I ate to add weight to my body?" -- Bunter122 

Today's question comes from a reader who would prefer to stay anonymous, but it is certainly a thought that many people have had. Given that we all have different metabolic speeds, what is the average amount of time it takes food to be digested and then shunted off to its various purposes?
"We have a pretty good indication about the timeline from the sequence of ingestion, digestion, and egestion. The whole thing plays out over a span of roughly 12 hours on average," says Dr. David Katz, a HuffPost Healthy Living contributor and director of the Yale University Prevention Research Center. "By the time the residual waste of food is passing out of us, the useable parts have all been put to use -- for energy expenditure, as heat generation, or placed into storage, as either glycogen [from carbohydrate], or fat."
After you eat, the food passes through your stomach and small intestine in about six to eight hours, according to the Mayo Clinic. Then, it enters the large intestine where it is further digested. Putting it as delicately as possible, Mayo Clinic gastroenterologist Dr. Michael F. Picco writes: "Elimination of undigested food residue through the large intestine usually begins after a total of 24 hours. Complete elimination from the body may take several days."
For a complete understanding of what the body does to digest food, the National Institutes of Health has a great explainer. For our purposes, it is essential to understand that as food is digested, enzymes and hormones are secreted by the stomach and small intestines (as well as fat cells) and work to break down the carbohydrates, protein and fat we've eaten into usable material for our cells.

A growing number of endocrinologists -- those who study our hormone system -- are beginning to see the hormone response as far more complicated than previously thought, as well as far more individualized: there is a wider variance in how people respond to food, they suspect.
"While the question posed seems extraordinarily simple, I don't think that there can be a simple answer to it," says Dr. Kaveh Ashrafi, an associate professor of physiology at the University of California, San Francisco School of Medicine who studies fat metabolism. "The prevailing view essentially considers feeding behavior/exercise as the sole determinants of body weight. For this to be true, one has to assume that the body itself is simply an inert vessel; if you put more food in it, it must get fat, if you move it, it must lose weight."

Why Am I Hungry After A Big Meal?

"The day after a big meal, I go to bed feeling stuffed and wake up hungrier than ever. Why is that? Is my stomach actually expanding?"
-- Jessi, 30, New York 

"I must admit that I get this sensation," says Dr. W. Timothy Garvey, Chair of the Department of Nutrition Sciences at the University of Alabama at Birmingham and Chairman of the Obesity Scientific Committee for the American Association of Clinical Endocrinologists. Several Healthy Living staffers also related. So the good news is that you aren't alone.
But there's bad news too. You stumped our experts. "The truth is, we don't have a rigorous scientific answer for this," Dr. Garvey told Healthy Living, echoing a common sentiment among all the researchers with whom we spoke. There were several plausible theories.
But first, more good news: it's not your stomach expanding. "There’s no truth to that at all," says Dr. David Greenwald, Associate Director of the Division of Gastroenterology at Montefiore Medical Center in New York. "It's more likely that the stuff they ate didn't fill them up properly. People who eat a lot, but don't eat good things are likely to feel hungry again [soon]."

Big meals are often celebratory, which means they may include foods that are decadent rather than nutritious: starchy vegetables like mashed potatoes, white dinner rolls, cake. Foods that fall high on the glycemic index can make your blood sugar spike, causing a surge of insulin to drag it back down. The quick vacillation in blood sugar can cause a disruption to the normal cycle of leptin -- a hormone secreted by the fat cells that signals to the brain when you've had enough to eat. Foods that cause this type of response can encourage what is sometimes termed "fullness resistance."
In other words, that big pasta festival for your birthday? It'll just make you hungrier. But meals full of veggies, whole grains and lean protein may not create the same effect. Then again, "people who are eating vegetables, leafy salads are probably not overeating," adds Greenwald.
Still, Garvey wasn't convinced that leptin and insulin were the culprits here. It takes weeks for leptin production to respond to a dietary change because it's related to the size of fat cells, rather than the contents of a single meal. Instead, he suspected that ghrelin, a completely different hunger hormone that controls short-term regulation might be responsible.
"Leptin is a long-term regulatory hormone. It increases overall the amount of calories you take in. If your fat cells get bigger, they make more leptin and that suppresses appetite. If fat cells shrink, they make less leptin and that stimulates appetite," he explains.
"But ghrelin is a hormone that is secreted by the stomach. When you eat something, ghrelin is suppressed, making you not want to eat more. As time progresses after meal, after several hours, ghrelin rises," he says. "Some people have more rapid and pronounced rises in ghrelin in response to what they eat and that makes them want to eat more."
So what can a person do to avoid the dreaded after-binge binge? Of course, the most obvious advice is to avoid it in the first place: reasonable portions can be celebratory too. Choose foods that will keep you full longer: things that are high-volume and low-calorie, like leafy greens, and full of protein and fiber, like beans.
Beyond that, all you can do is some damage control: eat a sensible, filling breakfast (oatmeal! egg-veggie scrambles!) and know that the increased hunger will pass.