It was long thought that to lose a pound, you needed to achieve a 3,500-calorie deficit by eating less or expending more energy (exercising)-or both. But in recent years, researchers such as Kevin Hall, Ph.D., at the National Institutes of Health, have basically debunked this thinking. While it’s true that the very first pound lost probably results from a 3,500-calorie deficit, the scenario changes after that. Basically, the interaction between calorie intake, expenditure, and weight is a dynamic one.
While cutting calories or increasing the energy you expend leads to weight loss, this is followed by a reduced expenditure of energy because your body is getting smaller (there is less of you to actively burn calories). During weight loss, your resting metabolic rate slows down, which is an unfortunate overprotective metabolic response to eating less. For most people, a sustained energy deficit also is typically followed by an increase in appetite-and consumption of more food.
Over time, a gradual slowing of weight loss-a plateau-occurs. If you’ve found a strategy for consistently cutting 500 calories from your daily diet, for example, you should lose weight. But if you keep up that approach for months and months, it’s unlikely you’ll keep losing weight at the same rate you did at first.
To avoid getting discouraged, it’s a good idea to prepare beforehand for this slowdown. If weight loss plateaus, be patient. Wait until your body and appetite stabilize and settle into this new, lower weight before trying again.