Exercise and Nutrition

Weight and Fat Loss

José Pablo Camacho A., NSCA-CPT
Reviewed on February 2026
Written on July 2017
3 min read
Weight and Fat Loss

Weight and Fat Loss

Diets primarily focused on Fat Mass (FM) loss (and weight loss beyond initial reductions in body water) operate under the fundamental mechanism of a sustained caloric deficit. This net hypocaloric balance can be imposed linearly/daily, or non-linearly/throughout the week.

Key Principles

  • The higher the baseline FM level, the more aggressively the caloric deficit can be imposed.
  • As subjects become leaner, slower rates of weight loss can better preserve Lean Mass (Fat-Free Mass).

Garthe et al. showed that a weekly reduction of 0.7% of body weight outperforms 1.4% for muscle preservation. Helms et al. similarly suggested a weekly pace of 0.5-1.0% of body weight for bodybuilders in contest preparation.

The Bottom Line

Any diet that seeks fat and weight reduction must allow us to eat a smaller amount of energy than we expend, in order to achieve a daily energy shortfall. Calorie reduction is the primary factor in fat loss. However, if the calorie reduction is too high, we lose muscle in the process. Additionally, this calorie reduction should not be absolutely every single day.

References

  1. Aragon AA, Schoenfeld BJ, Wildman R, et al. International society of sports nutrition position stand: diets and body composition. Journal of the International Society of Sports Nutrition. 2017;14:16. View Source