Question:

My friend has been working out for years and can’t seem to get slim. Is there such a thing as a set weight for your body?
— Nigel, Oklahoma City
  Steven Blair

Answer:

Obesity experts continue to debate the “set point” concept. Body weight is relatively resistant to change, either up or down, but it obviously occurs over time. Some experts have presented the concept of a “settling point”, meaning that your weight may settle at a new level. This new level is also subject to change with the passage of time, and depending on caloric balance.

To take a broader view, human beings come in various sizes and shapes. No one expects exercise to make all of us the same height, so why should we expect exercise to make all of us slim? Most of us will never be as slender as the models and movie stars often seen as ideals of beauty. My advice is to focus on what you can do, which is to eat a healthful diet and exercise regularly, and not obsess about your weight. Emphasize healthful behaviors and let your weight be what it will be.

In addition, our research shows that obese individuals who have high cardiorespiratory fitness have death rates less than one half the rates for lean individuals who are unfit. You can be overweight or even obese and still be healthy.