A STUDY shows that exercise reduces the level of basal metabolism, thus reducing the fat burning effect of exercise. The phenomenon is most pronounced among obese people and the elderly, making them losing fat more difficult.

The research, published by Current Biology on Friday, was led by Professor John Roger Speakman, who is currently working at the Institute of Biomedicine and Biotechnology in the Shenzhen Institutes of Advanced Technology (SIAT) of the Chinese Academy of Science (CAS). He is also a chief scientist for the college’s Center for Energy Metabolism and Reproduction.

The research group created a dataset consisting of 1,754 adults with body mass index (BMI) ranging from 12.5 to 61.7. BMI is used to broadly categorize a person’s weight level and health. Major adult BMI classifications are underweight (under 18.5 kg/m²), normal weight (20 to 25), overweight (25 and more) and obese (30 or more).

The study finds that the energy compensation increases from 27.7 percent for underweight people to 49.2 percent for overweight people.

The data indicated that overweight people compensate for about half of the calories burned during exercises, as their nonactivity energy expenditures drop by 49.9 percent. In contrast, only 27.7 percent of energy will be compensated for individuals with normal BMI.

“There are two possibilities leading to such energy compensation. One is that the exercise makes people ingest more food. The other is that the activity reduces body energy expenditures, such as non-activity energy expenditures,” explained Speakman.

(Xia Yuanjie)