Does sport really inhibit our appetite?

 

An interesting finding has been uncovered by a U.S. study team: a chemical is thought to make humans feel less hungry after a demanding workout. What is the purpose?

Sport benefits us both physically and mentally. In a perfect world, exercise would be enjoyable, but in any event, staying active daily helps us stay healthy and fit.

But does exercise impact our appetites as well? A recent study from Stanford University in the US found that working out hard actually reduces our feelings of hunger. What is the cause?

• It is believed that the "anti-hunger molecule" suppresses appetite.

A chemical that appears to cause us to eat less after exercise has been identified and studied by a research team at Stanford University in partnership with Baylor University and other universities. The chemical is known as Lac-Phe, or more specifically N-lactose-phenylalanine. It is produced using phenylalanine and lactate. When we exercise vigorously, our bodies release lactate, whereas phenylalanine is an amino acid necessary for the synthesis of proteins.

Jonathan Long's team of researchers put mice on a treadmill for their experiment: after the rodents dashed for a while, the team looked at how the chemicals in the cells of the little creatures altered. Increased Lac-Phe levels were measured by Long and his associates. It is an "anti-hunger molecule," as Jonathan Long and his team refer to it, according to additional tests. The more active mice consumed less food than the control group due to the higher Lac-Phe production.

• The study found that physical activity reduces hunger in people.

The first group of mice was given a high-fat diet and high doses of Lac-Phe for ten days as part of the experiment. The chemical was not given to the control group, who continued eating as usual. As a result, the Lac-Phe rodents consumed around 30% less food than the control group, reduced weight, and showed improved glucose tolerance.

The effectiveness of the "anti-hunger molecule" was also demonstrated in a subsequent test on racehorses. A human test was also conducted in tandem by Jonathan Long's colleague, who noted the rise in Lac-Phe following training.

• Researchers see new ways to combat disease.

This discovery excites the Stanford University team greatly. It might present completely novel solutions in the struggle against obesity's harmful effects and the diseases it causes. Before the discovery can actually help science, more study is required. It is still to be established whether and how individuals can benefit from the "anti-hunger molecule" and the subsequent decrease in appetite.

However, Jonathan Long remains upbeat: "We estimate that the Lac-Phe signaling pathway is responsible for roughly 25% of weight reduction through exercise," the study's director writes in a message on the school's website.