Cysteine may be at root of obesity

PEOPLE with high levels of the amino acid cysteine carry 6-10 kilograms more fat than other people, according to Norwegian researchers.

"There is a very high correlation between high levels of cysteine and obesity," explains Professor Helga Refsum of the University of Oslo's Department of Nutrition. The question is whether this is a causal relationship: How much is owing to genetic factors, and how much is affected by diet?

Professor Refsum's research indicates that cysteine plays a key role in how the body metabolises energy, stores fat, and breaks down fat. In their latest project, the researchers will also study how cysteine affects the brain - for instance, whether cysteine can influence the feeling of being satiated.