One Year of Caloric Restriction in Humans: Feasibility and Effects on Body Composition and Abdominal Adiposity

Researchers followed 48 healthy adults who were overweight but not obese. They randomly assigned them to eat 20% or 30% fewer calories, to eat 30% fewer calories while exercising, or to keep their usual diet. After one year, the calorie-restricted groups lost about 8% to 11% of their starting weight, mostly from body fat. They also lost abdominal fat, including visceral fat, which is fat stored deep around the organs. The study was small, and not everyone reached the planned calorie reduction.

What this means for you: Eating somewhat less can reduce body weight and abdominal fat over a year, but this study does not show that it extends life or is easy to maintain long term. No special diet product is supported by these results.