Scientists Find Hidden Amino Acid 'Switch' That Helps In Natural Weight Loss

Scientists in the United States have discovered a biological "switch" that could play a vital role in weight loss. The research highlights the importance of the amino acid cysteine, showing that its depletion can trigger the conversion of white fat, which stores energy, into brown fat, which burns calories and produces heat.

This process, the researchers explained, helps make the body's metabolic functions more efficient, offering a new way to understand how calorie reduction leads to weight loss. While earlier studies suggested cysteine might influence fat activity, this is the first direct evidence of its key role.

According to the team, keeping cysteine levels in check may serve as a new pathway for developing therapies to fight obesity and promote healthier metabolism.

"In addition to the dramatic weight loss and increase in fat burning resulting from the removal of cysteine, the amino acid is also central to redox balance and redox pathways in biology," said Dr Stadler, who directs the Oxidative Stress and Disease laboratory at Pennington Biomedical. "These results suggest future weight management strategies that might not rely exclusively on reducing caloric intake."

The research is based on results from trials involving both human participants and animal models. For the human trials, researchers examined fat tissue samples taken from trial participants who had actively restricted calorie intake over a year. When examining the fat tissue samples, they looked for changes in the thousands of metabolites, which are compounds formed when the body breaks down food and stores energy. The exploration of these metabolites indicated a reduced level of cysteine. 

"Reverse translation of a human caloric restriction trial identified a new player in energy metabolism," said Dr Ravussin, who holds the Douglas L Gordon Chair in Diabetes and Metabolism at Pennington Biomedical and oversees its Human Translation Physiology Lab. "Systemic cysteine depletion in mice causes weight loss with increased fat utilisation and browning of adipocytes."

The study has been featured in Nature Metabolism, a leading academic journal.