Research indicates that our weight is affected more by what we eat than by how much we eat

"A randomized controlled trial conducted by several institutions including Boston Children’s Hospital and the Harvard Medical School over three years and published last week in a peer-reviewed medical journal concludes that, “Consistent with the carbohydrate-insulin model, lowering dietary carbohydrate increased energy expenditure during weight loss maintenance."

"Research indicates that our weight is affected more by what we eat than by how much we eat" source

"This metabolic effect may improve the success of obesity treatment, especially among those with high insulin secretion.”

As summarized in ScienceDaily, “Most people regain the weight they lose from dieting within one or two years, in part because the body adapts by slowing metabolism and burning fewer calories. A meticulous study now finds that eating fewer carbohydrates increases the number of calories burned. The findings suggest that low-carb diets can help people maintain weight loss, making obesity treatment more effective.”

One of the study’s authors, Dr. David Ludwig, explains in the Los Angeles Times, “As anyone who’s gone on a diet knows, once you lose some weight, it gets harder to lose more. The ‘eat less, move more’ mantra, as simple as it sounds, doesn’t help us deal with our bodies’ metabolic reality: As we shed pounds, we get even hungrier and our metabolism slows down. But findings from a new study I led with my colleague Cara Ebbeling suggest that what we eat — not just how much — has a substantial effect on our metabolism and thus how much weight we gain or lose.”

Dr. Ludwig continues, “People have a hard time believing that weight control isn’t just a matter of calories eaten and calories burned. But there is an alternate hypothesis about obesity, which is what my group studies. The carbohydrate-insulin model argues that overeating isn’t the underlying cause of long-term weight gain. Instead, it’s the biological process of gaining weight that causes us to overeat. Here’s how this hypothesis goes: Consuming processed carbohydrates (especially refined grains, potato products and sugars), causes our bodies to produce more insulin. Too much insulin, one of the most powerful hormones, forces our fat cells into calorie-storage overdrive. These rapidly growing fat cells then hoard too many calories, leaving too few for the rest of the body. So we get hungry, and if we persist in eating less, our metabolism slows down.”" source, read more