Most of us have the basics ingrained in our brains. Eat less, eat healthy and exercise more. If only it were that easy. Having the right knowledge can make a big difference in how you act and react when it comes to your weight. Here are 10 things you may not know (but should) about your weight.
1. Some People Just Have More Fat Cells
And the range is enormous, with some people having twice as many fat cells as others have, says Kirsty Spalding, PhD, of the Karolinska Institute in Stockholm. Even if you've lost a few pounds (or gained some), your fat-cell count remains, holding tight to the fat already inside and forever thirsting to be filled up with more. (To add insult to injury, the fat cells of overweight and obese people hold more fat too.)
New fat cells emerge during childhood but seem to stop by adolescence. Those of us destined to have a lot of these cells probably start producing them as young as age two. The cells' rate of growth may be faster, too-even if kids cut way back on calories.
Strangers have written to Spalding, telling her how depressed they are by her research. But she says her news isn't all bleak. You're better off with more fat cells, she says, than with fewer fat cells that become overstuffed and enlarged. (New research suggests that the overstuffed group are more vulnerable to obesity-related health complications.) So while you can't reduce your total number of fat cells, there are things you can do to keep them small. (See next point.)
2. You Can Change Your Metabolism
Another Scandinavian team looked into what happens at the cellular level when you gain weight. Kirsi PietilÃ¤inen, PhD, an assistant professor of nutrition at Helsinki University Central Hospital, studied sets of twins where one was fat and the other thin, and learned that fat cells in heavier twins underwent metabolic changes that make it more difficult to burn fat. PietilÃ¤inen's team suspects that gaining as little as 11 pounds can slow metabolism and send you spiraling into a vicious cycle: As you gain more fat, it becomes harder to lose it.
How to get back on track? "The more I learn on the job, the more I'm convinced we need physical activity," PietilÃ¤inen says. Once a chubby child herself, she now runs regularly and is at a healthy weight.
3. Stress Fattens You Up
The most direct route is the food-in-mouth syndrome: Stressful circumstances (your bank account, your boss) spark cravings for carbohydrate-rich snack foods, which in turn calm stress hormones. (When researchers in one study took away high-carb food from stressed mice, their stress hormones surged.)
Stress hormones also ramp up fat storage. For our prehistoric ancestors, stress meant drought or approaching tigers, and a rapid-storage process made sense; we needed the extra energy to survive food shortages or do battle. Today we take our stress sitting down-and the unused calories accumulate in our midsection.
To whittle yourself back down to size, in addition to your usual workout routine, make time for stress relief-whether it's a yoga class or quality time with family.
4. Mom's Pregnancy Sealed Your Fate
A mother's cigarettes increase the risk of low birth weight, and alcohol can damage her baby's brain. So why wouldn't unhealthy foods wreak similar havoc? A growing body of science suggests that sugary and fatty foods, consumed even before you're born, do exactly that. A Pennington study on rodents reports that overweight females have higher levels of glucose and free fatty acids floating around in the womb than normal-weight ones do. These molecules trigger the release of proteins that can upset the appetite-control and metabolic systems in the developing brain.
What's true for mice is often true for humans too. Doctors from State University of New York Downstate Medical Center compared children born before their mothers had gastric bypass surgery with siblings born later. Women weighed less after the surgery, as expected, but their children were also half as likely to be obese. Because siblings have such similar genetic profiles, the researchers attributed the weight differences to changes in the womb environment. Moms-to-be, take note: You can give your kids a head start by eating well before they're born.
5. Sleep More, Lose More
When patients see Louis Aronne, MD, past president of the Obesity Society and author of the forthcoming book The Skinny, they're as likely to have their sleep assessed as their eating habits. If patients are getting less than seven to eight hours, Dr. Aronne may prescribe more shut-eye rather than the latest diet or drug. With more sleep, he says, "they have a greater sense of fullness, and they'll spontaneously lose weight."
Why? University of Chicago researchers reported that sleep deprivation upsets our hormone balance, triggering both a decrease in leptin (which helps you feel full) and an increase of ghrelin (which triggers hunger). As a result, we think we're hungry even though we aren't-and so we eat. Indeed, sleep may be the cheapest and easiest obesity treatment there is.
6. Your Spouse's Weight Matters
When Jodi Dixon's six-foot-two, 360-pound husband lost 125 pounds, she had mixed feelings. She was the one who always watched her weight and exercised; she was always the one trying to get her husband to be more active. Mort, a medical sales rep, was always the life of the party, says his wife, a 43-year-old mother of two in Freehold, New Jersey. But when he lost the weight, it was different.
"Men and women would flock to him, drawn to his charisma," she recalls. "I felt jealous." Dixon comforted herself with food and gained 20 pounds before she decided to take action. She began biking with her husband and enrolled in a diet program. Eventually she trimmed down, too, shedding 30 pounds, and has her sights on losing more.
Dixon credits the weight gain, and the loss, to her jealousy. But research shows that weight gain and loss can be, well, contagious. A study in the New England Journal of Medicine suggests that if one spouse is obese, the other is 37 percent more likely to become obese too. The researchers concluded that obesity seems to spread through social networks.
As in Dixon's case, slimming down seems to be catching, at least within the family: When Dixon launched her weight-loss plan, her eldest daughter, also overweight, followed her mom's healthy habits and lost 40 pounds.
7. Cookies Really Are Addictive
While food is not addictive the way cocaine or alcohol is, scientists in recent years have found some uncanny similarities. When subjects at Monell Chemical Senses Center in Philadelphia were shown the names of foods they liked, the parts of the brain that got excited were the same parts activated in drug addicts. It may have to do with dopamine, the hormone linked to motivation and pleasure, say researchers at Brookhaven National Laboratory in Upton, New York. If obese people have fewer dopamine receptors, they may need more food to get that pleasurable reaction.
8. Ear Infections Can Taint Your Taste Buds
For years, the team at Linda Bartoshuk's taste lab at the University of Florida wondered why people who tasted food less intensely than others seemed more likely to be fat. Researcher Derek Snyder had a theory: Could an ear infection, which can damage a taste nerve running through the middle ear, be the missing link? After tabulating 6,584 questionnaires, the team discovered that those over 35 who had suffered several ear infections had almost double the chance of being obese.
Responses to additional questions provided clues as to why. Former ear-infection patients were a little more likely to love sweets and fatty foods-perhaps because the damaged nerve causes them to have a higher threshold for sensing sweetness and fattiness. Even a small increase in calories from bad food choices adds up over time.
Childhood ear infections are as hard to avoid as the colds that tend to bring them on, but limiting passive smoke seems to drive down incidents of ear infection. If you're an overweight adult who suffered a severe ear infection as a child, it may be worth paying attention to the taste and texture of your food. Simply finding healthier substitutes, such as fruit instead of candy, or olive oil instead of butter, may help drive you toward eating better and weighing less.
9. Antioxidants Are Also Anti-Fat
Free radicals are now blamed not only for making you look old but also for making you fat. Zane Andrews, PhD, a neuroendocrinologist at Monash University in Australia, says these oxidizing molecules damage the cells that tell us we're full. Free radicals emerge when we eat (something even the keenest dieter must do to survive), but they're especially prevalent when we gorge on candy bars, chips, and other carbohydrates. With every passing year, these fullness signifiers suffer wear and tear-causing the "stop eating!" signal to get weaker and appetites (and possibly our stomachs) to get bigger. The best way to fight back? Avoid the junk and load up on colorful, antioxidant-rich fruits and vegetables.
10. You Can Be Fat and Fit
A growing body of literature suggests that size doesn't matter when it comes to your health. A study published in the Archives of Internal Medicine surveyed 5,440 American adults and found that 51 percent of the overweight and almost 32 percent of the obese had mostly normal cholesterol, blood sugar, blood pressure, and other measures of good health.
Further defying conventional wisdom, the article also reported that 23.5 percent of trim adults were, in fact, metabolically abnormal-making them more vulnerable to heart disease than their heavier counterparts.
The latest U.S. Department of Health and Human Services report corroborates what our doctors have said all along: You need about 30 minutes of moderate-intensity physical activity five days a week for health. And you don't even have to do your exercise in one fell swoop-ten-minute stints of walking are just as effective. That means if you forgo the elevators for the stairs, get off one train or bus stop earlier, and park your car a few blocks away, chances are you'll be good for the day.
Remember Steven Blair, the self-described short, fat, bald guy? At age 69, his blood pressure is in check, his cholesterol levels are normal, and his heart is strong. What's more, he may have even more positive vital signs, according to his recent study in the journal Obesity: Men who are fit (determined by their performance on a treadmill) have a lower risk of dying of cancer than out-of-shape guys, regardless of their body mass index, waist size, or percentage of body fat.
The news is heartening, says Blair: "We don't have great tools to change people's weight, but we know we can change their fitness levels.