In a recent study it is explored how dietary amino acids regulate energy expenditure and control adipose tissue function in mice. Existing research links caloric and methionine restriction in humans to increased “browning” of white fat, a process that enhances thermogenesis and supports core temperature maintenance. However, the specific role of individual amino acids in this metabolic shift remains unclear. This study focuses on the sulphur-containing amino acid cysteine, investigating its potential role as a nutrient signal that governs adipose tissue browning and metabolic regulation.
 
Core body temperature measured every 30 minutes
Scientist from Yale School of Medicine, Yale University, Washington University School of Medicine, AdventHealth, Pennington Biomedical Research Center, USA, Kyoto University Graduate School of Medicine, Japan, and University of Veterinary Medicine, Hungary, implanted mice with Star-Oddi’s DST nano-T loggers intra-peritoneally. The loggers were set to measure core body temperature every 30 minutes.

Fig. 1. J showing Cth^-/- mice fed control diet (black), or alternatively 75% cysteine (green line) with cysteine free diet (green line with red dots).

Increased body temperature with cysteine depletion
The researchers found that cysteine deprivation led to an increase in body temperature, indicating enhanced thermogenesis. This rise in temperature was linked to the activation of the sympathetic nervous system and the browning of white adipose tissue. Remarkably, even when fed a high-fat diet, cysteine-deficient mice exhibited substantial weight loss, improved metabolic profiles, and reduced inflammation. These findings position cysteine as a key dietary regulator of adipose tissue function and systemic metabolism.

This and further results can be read in the article published in Nature Metabolism.

Photo borrowed here