Scientists identify brain’s ‘fat controller’ nerve group

SCIENTISTS have identified the brain’s ‘fat controller’ — a group of nerves that sense changes in the body’s fuel supply to regulate appetite and metabolism.

The discovery could lead to new ways of helping obese people lose weight, either with drugs or carefully designed diets.

Researchers from the University of Cincinnati in the US demonstrated how a cell-signalling pathway known as mTOR allows the brain to sense how much energy the body has available.

The findings, reported yesterday in the journal Science, suggest that very specific micronutrients may be involved in the regulation of body weight.

mTOR could theoretically be manipulated to alter food intake, the researchers believe.

Professor Randy Seeley, who led the study, said: “We take in calories to maintain levels of stored fuel (energy) and adequate available fuel.

“The signals that tell our brain about both the stored and the available energy in our body can activate the mTOR pathway in key parts of the brain that control appetite.”

He said the mTOR pathway was highly sensitive to “branched-chain” amino acids, particularly one called leucine. His team found that when leucine was administered directly to the hypothalamus region of rodent brains, the animals ate less.

However, other similar amino acids did not provide the same results.

“Rather than basing our diets only on macronutrients like fat or carbohydrates, we might one day be designing diets based on micronutrients like amino acids,” said Prof Seeley.

But he warned people not to “run out and add more leucine to their diets”.

“We still have a lot to learn about how these nutrients would act if simply ingested with other nutrients, in what form they could be most effective, and even if they are effective at all when not administered directly to the brain.”