Weight loss: Better to cut calories or exercise more?

Mayo Clinic dietitian Katherine Zeratsky, R.D., L.D., and colleagues answer select questions from readers.

You may be referring to a study published in the Journal of Clinical Endocrinology & Metabolism. This six-month study examined the effects of diet alone (25 percent fewer calories consumed) versus diet plus exercise (12.5 percent fewer calories consumed and 12.5 percent more calories burned) in overweight but otherwise healthy adults.

Researchers hypothesized that the diet plus exercise group would lose more body fat, but results showed equal amounts of weight and fat lost in both groups.

This confirms that weight loss is all about calories: If you burn more calories than you eat, you'll lose weight. It doesn't mean exercise isn't important. Exercise has many health benefits. Plus, it can be tough to create a calorie deficit by diet alone.