IF has emerged as an alternative dietary intervention to CR, with equivalent benefits in body weight reduction, improvements in glucose homeostasis and lipid profiles, and anti-inflammatory effects. The beneficial effects of IF are mediated by reductions in body weight. Weight loss
per se improves insulin resistance, cardiovascular risks, and systemic inflammatory status because obesity functions as a common pathophysiology of these metabolic alterations, the “common soil hypothesis” [
97]. Moreover, the insulin-lowering effect is greater in IF than in CR resulting from fasting physiology, in which repetitive metabolic switching between feeding and fasting states improves the metabolic flexibility that is blunted in obesity and T2DM.
Although the general effects of IF are beneficial in terms of metabolic functions, some participants who participated in IF trials experienced reductions in bone density and lean body mass. Thus, careful monitoring, a protein-rich diet, and accompanying isometric resistance training are recommended to preserve lean body mass and bone density.