Eating too many or too few calories

Weight loss requires a calorie deficit. This means that you must burn more calories than you intake. For many years, it was believed that cutting 3,500 calories per week would result in a weight loss of 1 pound (0.45 kg). A recent study, however, suggests that the calorie deficit required differs from person to person.

Overeating is a major contributor to weight gain. You will gain weight if you consume more calories each day than you burn. Excessive calorie intake is driven by mindless eating, frequent snacking, and calorie-rich, nutrient-poor dietary choices. Paying attention to hunger and fullness cues by eating mindfully, eating a high-fiber, high-protein diet rich in plant foods, drinking water instead of calorie-dense drinks, and increasing your activity level are all simple ways to avoid overeating. On the other side, restricting your calorie intake too much might boomerang. Very low-calorie diets have been shown to cause muscle loss and dramatically slow metabolism in studies.