Yo-Yo Dieting Is Real—And It's Destroying Your Waistline

If you've ever been the victim of a yo-yo diet (cough, raises hand), you're not alone. In fact, that seems to be the norm for most people, according to new research presented at The Endocrine Society's annual meeting in Boston.

"About two-thirds of American adults are overweight or obese," said study lead author Joanna Huang, PharmD, senior manager of health economics and outcomes research at Novo Nordisk Inc., while presenting the findings. "Many patients regain weight after their initial loss; and even after a period of weight loss; most people become 'cyclers' who regain weight or experience inconsistent losses and gains." (This is especially alarming, considering recent research shows that 1 in 5 people will be obese by 2025.

So who are the people mostly likely to keep off the weight? That would be those who lose the most—as in, they potentially had the most drastic lifestyle changes.

Huang and her colleagues measured the individual BMIs (body mass index) of a whopping 177,000-plus obese subjects over a two-year period. First, they found that most subjects who had lost weight—regardless of how much—were likely to gain the weight back. Secondly, those classified as having a "high amount of weight loss" (more than 15 percent of their BMI) were far more likely to keep the weight off than their "moderate" or "modest" counterparts, who were grouped by having up to 10 percent and five percent BMI reductions, respectively. (Check out 10 Ditch-the-Scale Ways to Tell If You're Losing Weight.)

While more research clearly needs to be done in terms of why the weight loss-gain vicious cycle happens so frequently, this study highlights the need right now to focus on maintaining your weight (or losing it if you need to). For now, get familiar with The 10 Rules of Weight Loss That Lasts.