Popular culture tells us that women and men’s brains are just different. It’s true that male and female hormones affect brain development differently, and imaging studies have found brain differences in the ways women and men feel pain, make social decisions and cope with stress. The extent to which these differences are genetic versus shaped by experience — the old nature-versus-nurture debate — is unknown.

But for the most part, male and female brains (and brainpower) are similar. A 2005 American Psychologist analysis of research on gender differences found that in 78 percent of gender differences reported in other studies, the effect of gender on the behavior was in the small or close-to-zero range. And recent studies have debunked myths about the genders’ divergent abilities. A study published in the January 2010 Psychological Bulletin looked at almost half a million boys and girls from 69 countries and found no overall gap in math ability. Focusing on our differences may make for catchy book titles, but in neuroscience, nothing is ever that simple.

Brains never stop changing

Scientific wisdom once held that once you hit adulthood, your brain lost all ability to form new neural connections. This ability, called plasticity, was thought to be confined to infancy and childhood.

Wrong. A 2007 study on a stroke patient found that her brain had adapted to the damage to nerves carrying visual information by pulling similar information from other nerves. This followed several studies showing that adult mice could form new neurons. Later studies found more evidence of human neurons making new connections into adulthood; meanwhile, research on meditation showed that intense mental training can change both the structure and function of the brain.

Teen brains aren’t fully formed

Parents of stubborn teenagers rejoice, or at least relax: That adolescent attitude stems, in part, from the vagaries of brain development.

The gray matter of the brain peaks just before puberty and is pruned back down throughout adolescence, with some of the most dramatic development happening in the frontal lobes, the seat of judgment and decision-making.

A 2005 study published in the journal Child Development found that the parts of the brain responsible for multitasking don’t fully mature until we’re 16 or 17 years old. And research presented at the BA Festival of Science in 2006 revealed that teens also have a neural excuse for self-centeredness. When considering an action that would affect others, teens were less likely than adults to use the medial prefrontal cortex, an area associated with empathy and guilt. Teens learn empathy by practicing socializing, the researchers said. So much for grounding them until they’re 20.

The brain starts out as a tube

The foundation for the brain is set early. Three weeks after conception, a sheet of embryonic cells called the neural plate folds and fuses into the neural tube. This tissue will become the central nervous system.

The neural tube grows and differentiates throughout the first trimester. (When cells differentiate they specialize into various tissues needed to create body parts.) It isn’t until the second trimester that glia and neurons begin to form. The brain doesn’t wrinkle up until even later. At 24 weeks, magnetic resonance imaging shows just a few nascent grooves in the otherwise smooth surface of the fetal brain, according to a 2000 study in the journal Radiology. As the third trimester begins in week 26, the grooves deepen and the brain begins to look more like that of a newborn.

The brain is an exclusive club

Like bouncers at a night club, an assembly of cells in the brain’s blood system, called the blood-brain barrier, lets only a few molecules into the nervous system’s inner sanctum – the brain. The capillaries that feed the brain are lined with tightly bound cells, which keep out large molecules. Special proteins in the barrier transport necessary nutrients and substances into the brain. Only an elite few make it through.

The blood-brain barrier protects the brain, but it can also keep out lifesaving medications. Physicians trying to treat brain tumors can use drugs to open the junctions between cells, but that leaves the brain temporarily vulnerable to infection. One new way to sneak meds past the barrier might be nanotechnology. A 2009 study published in the journal Cancer Research showed that specially-engineered nanoparticles can cross the barrier and attach to tumor tissue. In the future, combining nanoparticles with chemotherapy drugs could be one way to target tumors.

Most of our brain cells are neurons

The old saw that we use just 10 percent of our brainpower isn’t true, but we now know that neurons make up just 10 percent of our brain cells. The other 90 percent, which account for about half the brain’s weight, are called glia, which means “glue” in Greek.

Neuroscientists used to think glia were simply the sticky stuff that holds neurons together. But recent research has shown glia to be much more. A 2005 paper in the journal Current Opinions in Neurobiology laid out the roles of these unsung cells, which range from mopping up excess neurotransmitters to providing immune protection to actually promoting and modulating synapse growth and function. (Synapses are the connections between neurons.) It turns out the silent majority isn’t so silent after all.

Wrinkles make us smart

What’s the secret to our species’ smarts? The answer may be wrinkles. The surface of the human brain is convoluted by deep fissures, smaller grooves called sulci, and ridges called gyri. This surface is called the cerebral cortex and is home to about 100 billion neurons, or nerve cells.

The folded, meandering surface allows the brain to pack in more surface area — and thus, more processing power — into the limited confines of the skull. Our primate relatives show varying degrees of convolution in their brains, as do other intelligent creatures like elephants. In fact, research done by Emory University neuroscientist Lori Marino has found that dolphins have even more pronounced brain wrinkles than humans.

Our brains burn through energy

The modern brain is an energy hog. The organ accounts for about 2 percent of body weight, but it uses about 20 percent of the oxygen in our blood and 25 percent of the glucose (sugars) circulating in our bloodstream, according to the American College of Neuropsychopharmacology.

These energy requirements have spurred a debate among anthropologists about what fueled the evolution of big brains in the first place. Many researchers credit meat, citing evidence of hunting in our early ancestors. But meat would have been an unreliable food source, say other scientists. A 2007 study published in the Proceedings of the National Academy of Science found that modern-day chimps know how to dig for calorie-rich tubers on the savanna. Perhaps our ancestors did the same, boosting their brainpower with veggies.

As for what motivated the brain to balloon in size, there are three major hypotheses: climate change, the demands of ecology, and social competition.

…But they’re getting smaller

Don’t get too cocky about your soda-bottle-sized brain. Humans 5,000 years ago had brains that were even larger.

“We do know from archaeological data that pretty much everywhere we can measure — Europe, China, South Africa, Australia — that brains have shrunk about 9 cubic inches (150 cubic centimeters), from an average of about 82 in^3 (1,350 cm^3). That’s roughly 10 percent,” University of Wisconsin at Madison paleoanthropologist John Hawks told LiveScience in 2009.

Researchers don’t know why brains might be shrinking, but some theorize that they’re evolving to be more efficient. Others think our skulls are getting smaller because our diets include more easily chewable foods and so large, strong jaws are no longer required.

Whatever the reason, brain size doesn’t directly correlate with intellect, so there’s no evidence that ancient man was brainier than humans of today.

Human brains are big…

The average adult brain weighs just under 3 pounds (between 1.3 and 1.4 kilograms). Some neurosurgeons describe the texture of a living brain as that of toothpaste, but according to neurosurgeon Katrina Firlik, a better analogy can be found in the local health-food store.

“[The brain] doesn’t spread like toothpaste. It doesn’t adhere to your fingers the way toothpaste does,” Firlik writes in her memoir, “Another Day in the Frontal Lobe: A Brain Surgeon Exposes Life on the Inside” (Random House, 2006). “Tofu — the soft variety, if you know tofu — may be a more accurate comparison.”

If you aren’t charmed by that description, consider this: About 80 percent of the contents of your cranium is brain, while equal amounts of blood and cerebrospinal fluid, the clear liquid that buffers neural tissue, make up the rest. If you were to blend up all of that brain, blood and fluid, it would come to about 1.7 liters, or not quite enough to fill a 2-liter soda bottle.

Kompas.com

But we don’t start out all that differently, nutritionally speaking.

“If you look at the current federal dietary guidelines for kids, there is no difference in nutritional needs for males and females until age 9,” says Elaine Turner, PhD, RD, associate professor in the department of Food Science and Human Nutrition at the University of Florida in Gainesville.

Once we hit puberty, however, she added, everything changes. And women’s unique role as the bearers of children tends to drive their special nutritional needs.

Women Need Fewer Calories

“A woman and man of the exact weight and percentage of fat would burn the same amount of calories for the same amount of exercise,” says Sharon B. Spalding, MEd, CSCS, professor of physical education and health at Mary Baldwin College in Staunton, Va. “However men are usually larger with a higher lean weight and will burn more calories.”

Body composition comes into the picture, she says, because we know that muscle takes more calories to maintain  even when you’re not exercising  than fat.

So women need fewer calories than men in part because they tend to be smaller and have higher fat percentages than men. That means women have to be choosier about what they eat. If you need fewer calories, the calories you take in need to pack a lot of nutritional punch.

In general, women need around 1,200 calories every day and men need a few hundred calories more. If you exercise you’ll need much more depending on how active you are.

“Remember that to determine caloric expenditure one must take into consideration the intensity and duration of the activity, as well as the body weight of the person exercising,” said Spalding.

More Iron, Please

For women of childbearing age, blood loss through menstruation can lead to iron deficiency. The Institute for Medicine of the National Academies recommends a daily allowance of 18 milligrams of iron for women aged 19 to 50. During pregnancy a woman’s requirements are even greater. Men in that same age range need just 8 milligrams daily.

“Iron is one of the few things women need way more of than men,” Spalding says.

Most men get all the iron that they need from the food they eat. For many women, it’s often not so easy, because they have lower calorie needs.

“Women need to eat a diet rich in meat, fish, and poultry,” says Spalding. “For vegetarian women it may be harder to get iron from dietary sources because the iron from plant foods is not absorbed as well.”

According to the American Dietetic Association, most grain foods we eat, such as cereals, pasta, and bread, are now fortified with iron. Some foods that are naturally high in iron include spinach, chard, beans (pinto, kidney, black), lentils, and split peas.

Increase the amount of iron you absorb from food by eating vitamin C-rich foods  orange juice, broccoli, tomatoes along with foods high in iron.

And remember, Turner notes, “women can be iron deficient and not be anemic. Being iron deficient can keep women from performing optimally.”


Calcium and Folate

Another area to watch is calcium.

“Women build bone into their mid-20s, and they need to eat calcium-rich foods to promote bone density,” says Spalding. “More calcium may be needed for women in menopause since with estrogen declines, calcium may ‘leak’ from the bones.”

The daily calcium recommendations are 1,000 milligrams a day for women under 50, and 1,500 milligrams a day for women 51 and older. Oddly enough, these are the same requirements for men, who are much less prone to osteoporosis than women. But the recommendation takes into account the fact that women are smaller than men. Thus the amount of daily calcium is greater for women on a proportional basis.

Both women and men need folate, or folic acid. At proper levels, it has been linked to better heart health and possible protection from colon cancer.

But for women in their childbearing years, getting enough of this B vitamin can greatly reduce the chances of neurological birth defects. The Institute of Medicine recommends 400 milligrams daily for people over age 14. Pregnant women need 600 milligrams daily, and women who are breastfeeding need 500 milligrams daily.

“It’s difficult to overstate the need for women to get sufficient folate before and during pregnancy,” says Turner. “It’s important for overall good health, but for the developing fetus, it can make all the difference in the world.”

By John Casey
WebMD Weight Loss Clinic

Organ: Your bladder

What it does:

The holding spot for urine formed in your kidneys until it’s time to go.

Keep it healthy:

1. Obey your urges. Waiting to hit the bathroom can stretch out your bladder, which may cause incontinence or a urinary tract infection. Feel the urge? Go to the ladies room!

2. Eat yogurt. Women who ate two servings of yogurt daily were less likely to develop bladder cancer than those who skipped the creamy stuff, research finds. The lactic acid bacteria may fight the disease, so choose a lowfat version with live cultures.

Organ: Your cervix

What it does:

This canal, which links your uterus with your vagina, flattens itself out to allow a baby to be born.

Keep it healthy:

1. Get regular exams. One out of seven American women skips her Pap smears. Without an exam, your doc can’t test for human papillomavirus (HPV) infections and cell abnormalities that up your risk for cervical cancer. Make an annual appointment and keep it.

2. Veg out. Women who ate a veggie-filled diet were more than 50 percent less likely to have lingering HPV infections, a study from the University of Arizona in Tucson finds. Got salad fatigue? Dig into this delish Chicken, Cashew and Vegetable Stir-Fry.

Organ: Your liver

What it does:

This organ, the largest in the body, sits under the ribs, where it breaks down harmful substances, manufactures about half the body’s cholesterol and processes sugars and releases them into the bloodstream as glucose.

Keep it healthy:

1. Stay at a right-for-you weight. Being pudgy puts you at greater risk for fatty liver, a disease that affects up to 40 million Americans. Find your ideal weight at Self.com.

2. Skip weight loss supplements. These specious shortcuts to slim can harm your liver, even in small amounts. Toss the pills and slim without sacrificing your health by using these easy, all-natural weight loss secrets to shrink a size or several.

Organ: Your lungs

What it does:

These two air bellows that surround the heart are responsible for every breath you take, bringing oxygen to your blood and sending it to your brain, and pushing carbon dioxide from your blood back into the atmosphere.

Keep it healthy:

1. Kick the sticks. Even occasional smoking can lead to cancer. Whatever is driving you to puff (stress? to avoid eating?), other habits you might take up in the absence of cigs (nail biting, nibbling chocolates) aren’t nearly as damaging as inhaling nicotine. Women often worry that they’ll gain weight after quitting. I promise, you’ll lose the pounds eventually. But there’s only one of you, so don’t squander your health smoking.

2. Give ’em a workout. Exercising improves lung capacity, helping your body shuttle more oxygen to your muscles to make everyday activities, like mopping the kitchen floor or playing with your moppets, feel easier.

3. Take a breather. In addition to zapping angst, a couple of minutes of deep breathing can help your lungs function better, delivering more oxygen to your body and bolstering your energy. Try this instant relaxer to mellow out the next time you’re feeling overwhelmed at work: Close your eyes and take five deep breaths, emphasizing the exhale. Consider the task you’re about to tackle. Think of a talent of yours (precision, people skills) you can use to succeed on the project. Envision the completed assignment, and then open your eyes. It’s a recipe for refreshed!

By Lucy Danziger

Whenever you eat food, your body has the option of burning that food for fuel, storing it for later energy or storing it in fat cells. The higher you keep your metabolism revved up, the faster you burn through the food in your system and the less likely you will be to store any of it as fat. Drinking water, especially ice water, acts like a catalyst to the body and fires it up, getting it ready for more energy. That is why when you are feeling a little sluggish you should get a big glass of ice water and gulp it down.

Go, Body, Go
Not to be indelicate here, but if you are not digesting your food properly, things tend to, well, back up. Without water, you do not break down food particles well enough and they make it to the end of the line in hard, dry masses that are difficult to deal with. Drinking enough water keeps progress moving along, smooth and easy.

No, Seconds, No
If you just ate a meal an hour ago, but you find yourself rooting around in the refrigerator, can you really say that you are hungry? When was the last time that you had something to drink? So many people cannot tell the difference between thirst and hunger because they are almost constantly feeling one (thirst) and never allow themselves to feel the other (hunger) at all. Take a day and learn to recognize the feeling of true hunger. Do not eat right away. Miss a meal. Miss two meals. How do you feel? That growling sensation in the pit of your stomach is hunger. Most of the time what you are feeling is thirst. Drink a glass of water or two, wait twenty minutes and see if you still feel like eating. If you do, then ask yourself if you are bored, mad, sad, and so on. If you are not eating out of boredom or an emotional trigger, have a small snack and then get out of the kitchen until your next regular meal.

More, Water, More
There is no magic amount of water that we should drink every day. The basic fact is that most of us need to drink more. So if you are drinking zero and add one glass per day, you have technically accomplished the goal of adding more. What works for one person may be too much or too little for another. Keep a bottle of water near you and take a drink as often as possible. If you feel like you are sloshing around, you have drunk too much water; pull back next time. Try to make water a daily part of your life not only for your weight loss goals but for all-around better health.

Written by Tom Nelson of theUltimate Fitness Gear, your top source for the Shaun T Insanity Workout on the internet.

What’s in a Chicken McNugget?

You’d think that a breaded lump of chicken would be pretty simple. Mostly, it would contain bread and chicken. But the McNugget and its peers at other fast-food restaurants are much more complicated creatures than that. The “meat” in the McNugget alone contains seven ingredients, some of which are made up of yet more ingredients. (Nope, it’s not just chicken. It’s also such nonchicken-related stuff as water, wheat starch, dextrose, safflower oil, and sodium phosphates.) The “meat” also contains something called “autolyzed yeast extract.” Then add another 20 ingredients that make up the breading, and you have the industrial chemical. I mean, fast-food meal, called the McNugget. Still, McDonald’s is practically all-natural compared to Wendy’s Chicken Nuggets, with 30 ingredients, and Burger King Chicken Fries, with a whopping 35 ingredients.

What’s in a Wendy’s Frosty?

Wendy’s Frosty requires 14 ingredients to create what traditional shakes achieve with only milk and ice cream. So what accounts for the double-digit ingredient list? Mostly a barrage of thickening agents that includes guar gum, cellulose gum, and carrageenan. And while that’s enough to disqualify it as a milk shake in our book, it’s nothing compared to the chemist’s list of ingredients in the restaurant’s new line of bulked-up Frankenfrosties.
Check out the Coffee Toffee Twisted Frosty, for instance. It seems harmless enough; the only additions, after all, are “coffee syrup” and “coffee toffee pieces.” The problem is that those two additions collectively ¬contain 25 extra ingredients, seven of which are sugars and three of which are oils. And get this: Rather than a classic syrup, the “coffee syrup” would more accurately be described as a blend of water, high-fructose corn syrup, and propylene glycol, a laxative chemical that’s used as an emulsifier in food and a filler in electronic cigarettes. Of all 10 ingredients it takes to make the syrup, coffee doesn’t show up until near the end, eight items down the list.

What’s in a Filet-O-Fish?

The world’s most famous fish sandwich begins as one of the ocean’s ugliest creatures. Filet-O-Fish, like many of the fish patties used by fast-food chains, is made predominantly from hoki, a gnarly, crazy-eyed fish found in the cold waters off the coast of New Zealand. In the past, McDonald’s has purchased up to 15 million pounds of hoki a year, each flaky fillet destined for a coat of batter, a bath of oil, a squirt of tartar, and a final resting place in a warm, squishy bun. But it seems the world’s appetite for this and other fried-fish sandwiches has proven too voracious, as New Zealand has been forced to cut the allowable catch over the years in order to keep the hoki population from collapsing. Don’t expect McDonald’s to scale down Filet-O-Fish output anytime soon, though; other whitefish like Alaskan pollock will likely fill in the gaps left by the hoki downturn. After all, once it’s battered and fried, do you really think you’ll know the difference?

What’s in my salami sandwich?

Salami, the mystery meat: Is it cow? Is it pig? Well, if you’re talking Genoa salami, like you’d get at Subway, then it’s both. Most salami is made from slaughterhouse leftovers that are gathered using “advanced meat recovery,” which sounds like a rehab center for vegans but is actually a mechanical process that strips the last remaining bits of muscle off the bone so nothing is wasted. It’s then processed using lactic acid, the waste product produced by bacteria in the meat. It both gives the salami its tangy flavor and cures it as well, making it an inhos¬pitable place for other bacteria to grow. Add in a bunch of salt and spices for a total of 15 ingredients in all and you’ve got salami. But now that you know what’s in there, you might need to check yourself into an advanced meat recovery center.

By David Zinczenko, with Matt Goulding

• Don't eat less than 1000 calories.
  
  Your body and metabolism thrive on food. When you fast, crash diet, or restrict calories below 1000, your metabolism will slow down in a response to conserve energy. Imagine your metabolism as a blazing fire... Feed the fire consistently with the appropriate amount of high-quality wood and it continues to burn at a good rate. If there is not enough wood, the fire goes out... Too much wood, it grows out of control -- just like your waistline!

• Eat every 4 to 5 hours.
  
  Because our bodies work hard to digest and absorb the foods we eat, your metabolism revs in response. This is called the thermic effect of food. Take full advantage and schedule meals and snacks every 4 to 5 hours.

• Make breakfast a priority.
  
  Studies show that people who regularly eat a healthy breakfast within 2 hours of rising are more likely to control their weight. Some of the reason may be because you're lifting your metabolic rate after it's been in a "resting phase" throughout the night.

• Protein with every meal.
  
  Eating all types of food creates a thermic effect and will slightly boost metabolism after consumption. However, the consumption of protein has the greatest metabolic boost when compared to carbohydrate and fat. Plus, eating the appropriate amount of protein will ensure you're able to maintain and build muscle mass (the more muscle mass you have, the greater your metabolism). Make sure to incorporate lean protein into most every meal (together with high-quality carbs) and get an appropriate amount each day.
  
  Daily Protein Requirements:
  
  Approximately 50% of your weight = daily grams of protein you need

  Some of the best protein sources include:

  • Fish
  • Chicken breast
  • Turkey breast
  • Lean red meat
  • Skim milk
  • Nonfat yogurt
  • Eggs and egg substitutes
  • Tofu
  • Beans and lentils

When it comes to EXERCISE...

• Do aerobic exercise 4 to 5 days each week.
  
  It’s obvious that aerobic activities like running, brisk walking, swimming, and bike riding burn calories and increase metabolism while you’re working out. But interestingly enough, several studies show that aerobic activities cause your metabolism to stay increased for a period of time after exercising. Aim to do some type of activity for at least 30 minutes, 4 to 5 times each week.
  
  
• Do strength training exercise 2 to 3 days each week.
  
  Lifting weights and/or doing other strengthening activities like push-ups and crunches on a regular basis will boost your resting metabolism 24/7. That’s because these activities build muscle, and muscle burns more calories than body fat. In fact, if you have more muscle, you burn more calories -- even while sitting still.

By Joy Bauer, M.S., R.D., C.D.N.