Fad Diets: Are Weight Loss Consumers Eating Up A Lie?
If a comprehensive new UCLA report gets its message across, the fad diet may soon be as dead as disco, but the conclusion only confirms what 50 million Americans on diets have learned to tune out for ages in their quest for an exercise-free magic bullet to kill fat. The review of 31 long-term diet studies appeared in the April issue of American Psychologist, lead authored by UCLA associate psychology professor Traci Mann. It could bring a sea of change for a $40 billion diet industry already feeling the burn of "carbs are back" messages in recent fast food commercials. For now, diet titans like Weight Watchers (WTW) and Lifetime Fitness Inc. (LTM) remain up (nearly ten and five points, respectively) over 2006 in the New York Stock Exchange, but Nutrisystem drags nearly 16 points down from its share price this time last year. And who can ignore the fact that Atkins Nutritionals, creators of the South Beach Diet, filed for bankruptcy well over a year ago. Though Mann’s review doesn’t compare diet plans, the results were striking across the board, with no clear winner. "There are hundreds of diet studies," Mann says, "but most only look at the short-term," where initial loss claims border on the miraculous. "We wanted to look at the long-term, to see if people kept the weight off." The majority of participants indeed lost five to ten percent of their weight within six months, but over four years, up to two-thirds of dieters gained back all the weight, and more. In fact, many studies indicated that past diet-plan weight loss is a leading predictor of future weight gain. The fad diet prognosis becomes even less rosy when the spotty data that backs weight loss claims studies is considered. Eight of the 31 studies Mann’s team reviewed had lower than 50 percent follow-up rates; most had participants report their own weight, and were never weighed by an impartial observer. Dieters flush with enthusiasm for the plan might massage their numbers to convince themselves that the plan is working, while backsliders tend to drop out without much fanfare. These biases, declares Mann, push outrageous weight loss claims into the realm of fantasy, but the diet customer, paradoxically, is hardly always right. "They may tell a lot of people that the diet sucked, but they don’t tell the clinician helping them. And they might not think the diet sucked. They give the diet credit for the amount they lost, and if they gain it back, they blame themselves." The Federal Trade Commission has launched over 100 investigations of diet programs in the last decade, but lack the resources to police those that fall short of clear malfeasance. The question of why diets fail is beyond the scope of Mann’s review, but the answer seems to be common sense. Michelle Murphy-Zive, MS, RD, principal investigator for the Regional Nutrition Network at UCSD, says that the simplest lessons about food and fitness are still better than any best-selling bacon Ponzi scheme. "Change the environment that you live in. Have fruits and vegetables cut up in your refrigerator, or skim mozzarella string cheese, so that when you feel compelled to snack, you go to those first. Restaurants serve huge portions. Eat half, take the rest home." The best diet includes all food groups in moderation, with a simple rule: you have to pay for it twice. Murphy-Zive explains, "You need to expend more energy than you take in by eating. You need 30 minutes of physical activity per day to burn what you eat." Busy dieters needn’t hit the gym every day but anyone can walk around the block a few times. "People say they don’t have the time, or they can’t stay on a diet for the rest of their life. We never say, ’diet,’ we say lifestyle change, and we talk to them about how to make these slow changes become habits." Murphy-Zive singles out Weight Watchers for its coordination of lifestyle changes and advice for eating out, but Mann counters that Weight Watchers fared no better than the rest in her study. Dieters chronically crawl from the wreckage of failed diet plans into shiny new ones because we crave a secret formula that will give us the same instant satisfaction as the food. Murphy-Zive puts it even more bluntly. "You can’t eat only bacon for the rest of your life. There is no magic pill, or I would be a millionaire." Mann’s study did find a minority who kept the weight off, but their secret weapon might scare you. "The one thing those people had in common was enormous amounts of exercise. Even the very pessimistic finding we had underestimated how many people gained it all back, because a lot of the people who gained the weight back did exercise. If they didn’t... good God." The new diet review is old news to Alberto Giacomelli, owner/lead trainer at La Jolla’s Penthouse Gym. "Everyone is different," he says, but, "Ninety-nine percent of people who come to my gym, and I am conservative, have no idea how to diet." Giacomelli tailors an exercise regimen to speed up the client’s metabolism and to keep them motivated over the long months necessary for real change. "Sometimes, it takes six to eight months before they see results. I tell them this is not fun. This is work. I guarantee you will get there, but you’ll have to sweat a lot. We have no control," he admits, "when they leave the gym." While he encourages his clients to enjoy a varied and balanced diet, Giacomelli reminds them that they’ll have to pay for it later, and he uses an ingenious method to make sure his lessons stick every time they go out to eat: he goes with them. "They send me a picture of every meal they get. I get a picture in their file, and when they come back, I tell them, ’That’s too much pasta,’ or, ’maybe no sauce at all, next time.’" — Cody Goodfellow