“Over the last several years and decades (low-fat) had been recommended as the way to lose and keep off weight, but obesity rates only increased,” said lead author Dr. Diedre K. Tobias of Brigham and Women’s Hospital in Boston. Over one year or more, low-carb diets yield a couple more pounds of weight loss on average, but that’s not meaningful for most people, she said. Low-carb diets tended to lead to about 1.15 kilograms, or 2.5 pounds, more weight loss than low-fat diets in 18 comparisons.