If, like millions of people, you've been on diets, perhaps lots of them, researcher Traci Mann says you should be relieved to know that it's not a flaw in your character that they didn't work. Or at least they didn't work for long.
That may seem to make sense to many people who have invested time, money, energy and hope in the latest diet in a multibillion-dollar industry. If any of those "secrets" to the perfect body actually proved true, there'd be little need for any more. And there are always more.
"The issue is that you can lose weight on practically any diet. The problem is that the weight comes back" for around 95% of people, said Mann, founder of the Health and Eating Lab at the University of Minnesota, where she is a professor of social and health psychology.
"You can stop dieting and still be healthy," Mann said in an interview about her new book, "Secrets From the Eating Lab," an overview of dieting, willpower and health. And if you've lost weight on a diet only to regain it, she said, "it's really not your fault" but more likely the result of your biology, stress and the allure of "forbidden fruit."
That might come as bad news for anyone determined to diet to skinny.
If you want to stay thinner than your body's natural range allows, Mann said, "you're going to be dealing with that five or six times every day — meal times, snack times, when you should be exercising. It's going to have to become a huge main focus of your life. That just seems crazy to me."
And dieting itself, Mann writes, can cause stress, low self-esteem and guilt.
Even the simple advice to eat less, move more is unlikely to work for people who have been obese for more than a couple of years, a group of doctors wrote recently in the journal Lancet Diabetes & Endocrinology.
Few diet studies are randomly controlled and follow participants for years, Mann said. Her lab was able to find just 21 such studies. Among those, dieters were followed for up to 10 years and had managed to "keep off, on average, a measly two pounds," she wrote.
Kelly Brownell, an expert on obesity and the dean of the Sanford School of Public Policy at Duke University and who was not involved with the book, agreed that there is "a lot of biological pressure to regain weight" that has been dieted away. Between two 150-pound women, one of whom has lost 50 pounds to get there and one whose weight falls there naturally, "they are much different from each other metabolically."
OK. But with all the news about the health problems of obesity, what can we do? What should we do?
Mann takes on the conventional wisdom that being obese is a death sentence. Mortality from obesity is an issue only for the very heaviest, she writes. And moreover, while overweight and obese people are more likely than normal-weight people to get diabetes and some other diseases, there's something researchers call the obesity paradox: Those same people sometimes have a better prognosis once they get diseases, she writes. Her work suggests there's a lot researchers have yet to uncover about the relationship between being overweight and health.
Obesity presents a "statistical morass," Brownell said. It's a challenge to study its effects independent of risk factors, but he said it's not necessarily important to test its effects on its own because it's rarely uncoupled from those risk factors — diabetes or high blood pressure, for example. In studies published early this year, researchers found that it is possible to be obese and healthy but that those people are rare and their conditions are likely to change over time.
Mann advocates — and Brownell said he agrees with the idea — what she calls "your leanest livable weight," or put another way: "a weight you can maintain while having a normal life. If it's a weight you cannot maintain, that is not your leanest livable weight."
That number might be hard to discern, especially in people who have been constantly dieting or binging. For many people, Mann said, it's likely to mean accepting a few more pounds than you've been prepared to consider OK. "I know it's hard to say we should accept our weight. Most of us want to look different."
Mann — who has been on a diet only once, for just two weeks, and who loves ice cream, especially rocky road — does not suggest that we give up altogether. She offers some research-based ways to change unhealthful eating habits and get to that leanest livable weight.
"The easiest thing to do is get alone with a vegetable," Mann said. What she means is to eat a vegetable before a meal. Not with all sorts of other choices on the table — just a vegetable, perhaps a salad, before the rest of the meal. That will cause you to eat less at the meal; Mann has tried this with students, without telling them to eat less or watch calories. But they did eat less, she said, "because they got full."
She has a dozen strategies in her book to lead people to eat more healthful food without effort, including not driving by the bakery that sells your favorite pastry. Along the same "out of sight, out of mind" line, when Google switched free candy in its New York office from clear to opaque containers, the 2,000 employees ate 3 million fewer calories in seven weeks.
Simple as some of these strategies seem, they work, she writes.