The Surprising Truth About 8 Common Diet Strategies

Who has the time to keep up with weight-loss research? It's so technical...and confusing...and often contradictory! And yet if you don't know what's going on in the world of calorie counting, you may not be seeing the pounds drop off as fast as you think they should. In one European diet-and-exercise study, for example, participants who were given detailed explanations of the research itself were more likely to improve (exercise more or eat better or both) than a less clued-in group. Fortunately, we have dug into the latest research. And as we did, we noted that a surprising number of dieting tactics accepted as gospel have recently been shown to be dead wrong. Knowing which still hold up and which are big (fat) lies can mean the difference between winning and losing at weight loss. Here's the lowdown.

1. To lose a pound, you must cut 3,500 calories

FALSE: This much-quoted equation doesn't account for the slowdown that happens to your metabolism as you drop pounds, explain researchers at the National Institutes of Health. "As a result, it drastically overestimates how quickly people will lose weight," says senior investigator Kevin D. Hall, Ph.D. That's why his team has created a new, computerized model that accurately predicts just how long you'll have to say non to french fries. It takes into consideration not only the drop in calorie burn as you get slimmer, but also your current weight, your age, how much you're eating now, and other variables.

Let's say you're a 46-year-old woman who weighs 170 pounds. According to the traditional formula, if you cut 500 calories a day, you would drop a pound a week (500 ≈ 7 days = 3,500 calories, or 1 pound) - and lose 26 pounds in six months. But the new math shows that the weight loss is more likely to be 19.5 pounds.

Make this work for you: The weight-loss gods may be cruel, but knowing what to expect can keep you from getting discouraged - and from backsliding - when the scale seems stuck. To try the new Body Weight Simulator, go to bwsimulator.niddk.nih.gov. Especially cool: You can vary predictions of how much you might lose and how long it will take by changing what you plug in for your calorie intake and exercise level.


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2. Three squares a day works as well as a "many mini meals" plan

TRUE: Dieters who stick to breakfast, lunch, and dinner are often no hungrier than those who opt to have frequent small meals and snacks throughout the day, a new University of Missouri study found. Actually, if you're a dieter who doesn't want to have to be extra careful about portion control, eating three squares might be a better strategy. "Often people misinterpret the size of a 'mini meal' and end up taking in far more calories than they realize," says lead author Heather J. Leidy, Ph.D. "Also, more meals means more exposure to food, which creates more opportunities for overeating."

Make this work for you: Whether you want to be a traditionalist or a conscientious "mini meal" strategist, the most important thing is not to go too low: Dieters who dine only once or twice a day tend to get ravenous - and we all know where that leads.

3. A history of yo-yo dieting wrecks your chances of future weight-loss success

FALSE: This idea gained traction back in the 1980s, when studies on rats found that those forced to yo-yo with their diets actually became more efficient at gaining weight. Humans, however, are luckier: In new research from the Fred Hutchinson Cancer Research Center in Seattle, a history of losing, then gaining, then losing wasn't linked to any negative effects on metabolism. Even severe yo-yo dieters - women who reported losing 20 or more pounds on three or more occasions - were able to follow a new diet and exercise program just as successfully as non-swingers.

Make this work for you: Yo-yoers are often women who try one crash diet after another. So take encouragement from this study and look for a plan that focuses on healthy lifestyle changes that lead to slow and steady weight loss. One to consider: GH's Drop 5 lbs: The Small Changes, Big Results Diet ($5; exclusive edition available at Kohl's).

4. Exercise does not burn off pounds

TRUE: It's hard to believe, but in a study of 411 women, those who worked out for over one, two, or three hours a week for six months didn't lose significantly more weight than those who'd devoted themselves to Sudoku or other sedentary pursuits. You'd think this finding was a fluke, but a recent review of 15 studies came to the same conclusion: Moderate workouts don't lead to weight loss, possibly because they make us hungrier. But there's also a biological explanation: As with weight loss, one of the ways your body adapts to an increase in exercise is to lower your resting metabolic rate about 7%, so you actually end up burning fewer calories - anywhere from 50 to 75 fewer per day, the review found.

Make this work for you: While exercise doesn't burn off the bulge, "it does boost your PFF: Pants Fit Factor," says Diana M. Thomas, Ph.D., of Montclair State University in New Jersey. "It helps reduce your waist and gives you a firmer, leaner-looking shape overall." What's more, a dwindling waistline is a key indicator that you're losing belly fat - the dangerous fat type that's linked to health problems like heart disease and diabetes.


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5. It's best to set challenging weight-loss goals

TRUE: Weight-loss experts have long counseled that if dieters set high - that is, unrealistic - targets, they'll quickly get discouraged and give up. Better, the pros have advised, to think small. But in a recent study of 447 overweight adults, Dutch researchers found that the more weight loss the participants strived for, the more effort they made - and the more weight they reported losing after two months. One theory as to why being ambitious might help you shed more pounds: It has a psychologically energizing effect, pumping up your commitment and drive.

Make this work for you: When mapping out a pounds-off plan, go for the gold - or strive to lose 14% of your current weight. That's the target (on average) that motivated the higher-reaching dieters in the Dutch study. For a 165-pound woman, that works out to about a 23-pound loss.

6. Milk drinkers lose more weight

FALSE: Wipe that mustache off your face: When Harvard researchers analyzed 29 studies on the topic, they found that while dairy may help dieters in the short term, ultimately it's not a winning (i.e, losing) strategy. In fact, in most of the studies that had lasted a year or longer and that didn't restrict calories, adults who chugged extra glasses of the white stuff (or ate more dairy) actually gained more weight than participants who didn't.

Make this work for you: To satisfy your dairy cravings, sub in yogurt: The Harvard team noted that a recent large study did find yogurt intake helped with weight in the long term.

7. Tracking carbs is the best way to keep pounds off

FALSE: A balanced plan topped the usual technique of counting carbohydrates or fat grams in a study of adults who had recently lost a significant amount of weight. The least successful of the plans was the one that counted fat grams: It caused the biggest slowdown in metabolism, leading dieters to burn an average of 423 fewer calories a day. The carb-counting plan was problematic because it caused an increase in cortisol and C-reactive protein levels - factors that may elevate your risk of cardiovascular disease. In contrast, the balanced plan caused a less extreme drop in metabolism (under 300 calories a day) and didn't trigger any heart-harming consequences.

Make this work for you: The study's balanced plan included lots of whole grains, fresh vegetables, legumes, fruits, nuts, healthy fats like olive oil, and lean fish and meats; it excluded heavily processed foods like white bread and instant rice. Known as "low-glycemic," this type of diet is based on regulating the body's blood sugar and hormone levels. It may also be the easiest diet to stick to in the long term because it doesn't restrict entire classes of food, notes lead study author Cara B. Ebbeling, Ph.D., of Boston Children's Hospital. For info, go to childrenshospital.org (search "low-glycemic diet" for shopping lists and other tips).


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8. You have to watch what you eat - forever

TRUE: Previously, experts believed if you restrained eating for too long, it would backfire and lead to bingeing, notes weight-loss researcher Fiona Johnson, Ph.D., of University College London. "But the constant bombardment of food temptations has led to a situation where self-control is essential."

Make this work for you: Psychologists specializing in dieting issues don't advocate outlawing a long list of favorite foods. Instead, they suggest "flexible restraint" - passing on sundaes or fries on most days, but occasionally allowing yourself those treats. To monitor how well you're balancing restraint with indulgence, step on your scale at least once a week. Regular weigh-ins will alert you to the need to rein in before a big, hard-to-shake weight gain settles in.

Which diet strategies work, or don't work, for you? Let me know in the comments!

-by Janice Graham

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