The Gravitostat theory: Body fat is lost but is fat-free mass preserved?

The gravitostat theory: More data needed

“…In our recent proof-of-concept randomized clinical trial we found that increased weight loading for 3 weeks reduces body weight and body fat mass, but not fat free mass, also in obese humans [1]. It is possible that the difference in effect on fat mass and non-fat mass is more pronounced after increased loading than in other fat-reducing models such as caloric restriction as suggested by Thivel and Boirie [3]. However, we have not yet directly compared the effects of increased weight loading and caloric restriction on fat mass and fat free mass in the same clinical or preclinical study.…”

“…Thus, activation of the gravitostat primarily protects against obesity by suppressing body fat mass but not fat free mass. Further studies are clearly warranted to determine why activation of the gravitostat preferentially reduces fat mass in obese subjects as suggested by Thivel & Boirie [3].…”

“…We thank Drs Thivel and Boirie for bringing up additional aspects of our recent randomized clinical trial published in EClini-calMedicine [1] on the hypothetical body weight regulating system that we previously coined "the gravitostat" [2]. As pointed out by Thivel and Boirie, [3] in several preclinical studies, we found that activation of the gravitostat by increased loading decreases fat mass substantially, while there is little or no effect on fat free mass in obese experimental animals [2,4,5]. In our recent proof-of-concept randomized clinical trial we found that increased weight loading for 3 weeks reduces body weight and body fat mass, but not fat free mass, also in obese humans [1].…”