13 Things You Never Knew About Losing Weight

Weight loss is a science, and a fascinating one at that. You won't look at diets the same way after learning the facts behind today's fat-busting finds.

By Joanne Chen
Also in Reader's Digest Magazine January 2009

8. Achoo! A Virus Can Cause Obesity

Adenoviruses are responsible for a host of ills, from upper respiratory tract problems to gastrointestinal troubles. The link to fat was uncovered when researchers at the University of Wisconsin injected chickens with the viruses and found that certain strains fattened them up.

Stem cells, known for their chameleonlike abilities to transform, also turned into fat cells when infected with the viruses. “The virus seems to increase the number of fat cells in the body as well as the fat content of these cells,” says Nikhil Dhurandhar, PhD, now an associate professor of infections and obesity at Pennington.

Human studies, including comparisons of twins, suggest that obese people are indeed more likely to harbor antibodies for a particular virus, known as adenovirus-36.

We have flu shots; could an obesity vaccine be the next step? It may sound far-fetched, but “that’s what they said about cervical cancer too,” says Dhurandhar.

9. 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.

10. 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.

11. 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.

12. Pick a Diet, Any Diet

As established diet books constantly reinvent themselves to sell copies and win converts, a curious phenomenon has emerged: Ornish, Atkins, and everyone in between are sounding remarkably similar. The low-fat gurus now say that certain fats are okay, while the low-carb proponents are beginning to endorse whole grains. With every new guideline and selling point, each diet acknowledges that there are really four basic rules to healthy eating (drumroll, please):

  • Consume carbs in the form of whole grains and fiber.
  • Avoid trans fats and saturated fats.
  • Eat lean protein.
  • Fill up on fruits and vegetables.

The low-carb South Beach Diet, for example, now espouses the virtues of eating the Mediterranean way-including lots of carbohydrate-rich fruits and vegetables. The latest Atkins book emphasizes the “good carb” message too. Weight Watchers, a champion of the points system, is now offering a “no counting” option based on healthy choices like those above. Jenny Craig is pushing Volumetrics, a high-volume, low-calorie strategy. And everyone gives a thumbs-down to processed and sugary carbohydrates, which cause insulin to spike and can lead to more fat and even diabetes.

Low-fat-diet guru Dean Ornish, MD, says, “It’s the end of the diet wars.” His most recent book, The Spectrum, even offers recipes that can be prepared in various “degrees”—from a vegetable chili served plain (low-fat) to one served with olives (more fat) to still another served with turkey breast sausage (still more fat).

The key to all of this, of course, is moderation rather than deprivation—eating in a way you can live with. And for some people, an important side effect of eating more plant-based foods is that it’s better for the environment. (See food writer Mark Bittman’s Simple Till Six: An Eating Plan for Busy People.)

13. 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.

New Way to Tame Cravings?
Some of the most eagerly awaited pills in the pipeline promise to calm cravings, reduce appetite, and even boost metabolism.

For instance, vigabatrin has been studied as a treatment for drug addiction. Suspecting that it would work on weight-control patients, scientists injected the substance into obese rats. It worked: The rats lost 19 percent of their original weight after 40 days.

Another drug, tesofensine, works on three different mechanisms in the brain to regulate appetite and metabolism. In early trials, patients who used the drug lost an average of nearly 30 pounds.

So what’s the catch? Side effects. The much-hyped drugs taranabant and Acomplia both failed because they caused severe mood swings and depression. Scientists will have to pay close attention to dosage and side effects if future weight-loss drugs are to clear the FDA approval process.

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