does fasting affect basal metalbolism

Fasting can impact basal metabolism in several ways. As Andrew Huberman explains, basal metabolic rate can be influenced by various factors, including hormone levels such as thyroid hormone, insulin, growth hormone, testosterone, and estrogen, which all affect the calories burned component of the metabolic equation. Specifically, fasting practices like time-restricted feeding have been shown to have significant effects on weight loss and fat loss through mechanisms related to these hormones 1.

Another important aspect discussed is the connection between fasting and the basal metabolic rate relates to how fasting might alter body fat distribution and composition. For instance, the usage of GLP-1 (a gut-derived peptide) in fasting scenarios is noted to increase the basal metabolic rate. This occurs through mechanisms such as the conversion of white fat cells to metabolically active beige and brown fat cells, which enhances the metabolic rate 2.

Therefore, fasting does affect basal metabolism by altering hormone levels and body fat composition, resulting in changes to the energy expenditure of the body.