Weight control in a pill?
A collaborative effort led by researchers at Baylor College of Medicine (Baylor) looks into the possibility of packaging the benefits of exercise – in relation to weight management – into pill form. The researchers have identified a molecule in the blood that is produced during exercise that might be used in oral form to effectively reduce food intake and obesity.
Regular exercise has been proven to help weight loss, regulate appetite, and improve metabolism, said Dr. Yong Xu, professor of paediatrics-nutrition and molecular and cellular biology at Baylor. However, in older or frail people who cannot exercise, therapeutic interventions that provide the same mobility and health benefits as regular exercise would be greatly beneficial.
Dr. Xu and colleagues first analysed the blood plasma profile of mice following an intense bout of exercise and found that it induced the modification of an amino acid called Lac-Phe. Lac-Phe is synthesised from lactate (responsible for the burning sensation in muscles after strenuous exercise) and phenylalanine (an amino acid that is one of the building blocks of proteins).
In experiments in mice on a high-fat diet, a high dose of Lac-Phe was observed to suppress their food intake by about 50% without affecting their movement or energy expenditure, compared to control mice – this observation was made over a period of 12 hours. When administered to the mice for 10 days, Lac-Phe reduced cumulative food intake and body weight (owing to loss of body fat) and improved glucose tolerance.
The researchers also identified an enzyme called CNDP2 that is involved in the production of Lac-Phe. Mice lacking this enzyme appeared not to lose as much weight on an exercise regime as a control group on the same exercise plan.
Later experiments with racehorses and humans showed robust elevations in plasma Lac-Phe levels following physical activity, which subsequently regulated feeding habits. Data from a human exercise cohort showed that sprint exercise induced the most dramatic increase in plasma Lac-Phe, followed by resistance training and then endurance training.
