We know exercise is good for weight loss, but how does it help us exactly? Stanford Medicine researchers say a newly-discovered “anti-hunger” molecule that curbs appetite after exercise may be at play.
They’re calling this molecule lac-phe, a hybrid of lactate and phenylalanine. Lactate, or lactic acid, is a byproduct of glycogen produced during anaerobic exercise—intense exercise of shorter duration. Phenylalanine is an amino acid that makes proteins, adrenal gland hormones, and melanin responsible for skin pigmentation.
One of the researchers, assistant professor of pathology at Stanford, Jonathan Long, PhD, explained some of the details they’ve uncovered on how lac-phe is formed. Lac-phe is formed during exercise with the help of a protein with high activity levels in immune and skin cells, CNDP2. “That means when we exercise, many different types of immune cells sense lactate, and then CNDP2 helps create lac-phe.”
Long and his team discovered lac-phe through animal studies and mass spectrometers. To examine molecular changes associated with exercise, the researchers examined the blood of mice through mass spectrometry before and after the mice ran on treadmills. The one eventually coined lac-phe, a molecule with a mass of 236, spiked the most. These researchers also found a similar increase in racehorses, strengthening the argument that this spike is exercise-induced. Long’s colleague, Michael Snyder, PhD, professor and chair of genetics and the Stanford W. Ascherman, MD, FACS, found this same increase in the molecule with the 236 mass in his separate research. Snyder’s team had just decoded this molecule’s chemical formula showing it was the hybrid of lactate and phenylalanine.
To better-study lac-phe’s effects on appetite, Long's team gave obese mice lac-phe and found they weren’t as hungry and ate less of their calorie-rich food. “We saw their food intake was suppressed by about 30%,” stated Long. “That led to reduced body weight, reduced fat and improved glucose tolerance, indicative of a reversal of diabetes.”
The discovery of lac-phe is an accomplishment for the field of metabolomics and another clue in understanding the biology of exercise. Researchers in this field have been cataloging thousands of molecules involved in metabolism over the years, and there are potentially thousands of more waiting to be discovered.