Signals initiated following the consumption of food reach a part of the brain called the hypothalamus, telling it about the body's nutritional status and triggering growth. Researchers from the University of Cambridge, alongside teams from Queen Mary University of London, University of Bristol, University of Michigan and Vanderbilt University have used the study of genetic variation to clarify a role for one of the brain’s receptors, known as the melanocortin 3 receptor (MC3R), in growth and pubertal development.

The new research, published in Nature, found that the MC3R receptor system controls the release of key hormones regulating growth and sexual maturation in response to nutritional signals. When this brain receptor doesn't work normally in humans, people tended to be shorter in height, and started puberty later than other people.

Humans have been growing taller and reaching sexual maturity earlier over the past century. University of Cambridge Professor and study co-author, Sir Stephen O'Rahilly, said: “Identifying the pathway in the brain whereby nutrition turns into growth and puberty explains a global phenomenon of increasing height and decreasing age at puberty that has puzzled scientists for a century."

Scientists searched amongst the half a million volunteers in UK Biobank for people with naturally occurring genetic mutations that disrupt the function of the MC3R gene. They identified a few thousand people who carried various mutations in the gene for MC3R and found these people were on average shorter and went into puberty later than those with no mutation.

To confirm these findings in children, they studied almost 6,000 participants from the Avon Longitudinal Study of Parents and Children (ALSPAC) and identified children with mutations in the MC3R gene. The children were again shorter and had marginally lower lean mass and weight throughout childhood, showing that this effect is likely to start very early in life.

Co-author, Kaitlin Wade, from the University of Bristol was funded and supported by the Elizabeth Blackwell Institute. Kaitlin Wade said: “The discovery, which sheds more light on how the brain, our genetics and our nutritional surroundings all interact, has wider implications for health. It could lead to the development of targeted strategies to help children with serious delays in growth and puberty.”