90% of people gain back the weight they lost within a year. 2/3 of Americans are obese or overweight, so many of us are chronic yo-yo dieters, following an endless cycle of weight loss and weight gain. These people would be better off staying overweight than constantly increasing and decreasing weight.
Donald Layman and colleagues from the University of Illinois found that people could sustain weight loss and promote long-term positive changes in body composition and blood fats by increasing daily protein intake to 1.6 grams of protein per kilogram body weight (the RDA for protein is 0.8 grams per kilogram body weight). After 12 months, a group following a diet with moderately-increased protein content showed more fat loss, lower blood triglycerides (fat) and higher HDL (good cholesterol) than a group eating less protein and more carbohydrates. Increased dietary protein promotes long-term weight maintenance and improved body composition.
(Journal Nutrition, 139: 514-521, 2009)