In what is a surprising and frustrating twist, researchers with the Chinese Academy of Sciences’ Shenzhen Institute of Advanced Technology and the University of Roehampton have found that activity doesn’t have the same effect on weight loss in obese individuals as it does in people who have a normal BMI. Put simply, exercising causes the body to burn fewer calories when resting later on.
The study, which was recently published in Current Biology, involved data on 1,750 adults. By evaluating how many daily calories were burned by activity versus at rest in a day, the researchers determined that obese individuals burn significantly lower calories at rest compared to people with a normal BMI after exercise.
Based on the participants who were studied, 51-percent of daily calories burned by obese individuals happened during activity; this was compared to 72-percent in normal-weight individuals. The researchers explained that in obese individuals, exercise triggers a decrease in resting metabolism that is akin to ‘saving’ half a calorie for every calorie burned by physical activity.
In older adults, meanwhile, the study found that the decrease observed is more commonly due to compensating for the energy burned by eating more later on and similar things. The researchers note that calorie-cutting recommendations for weight loss don’t account for the changes in metabolism that obese individuals experience as a consequence of activity.
This unfortunate plot twist makes it harder for an obese adult to lose weight with physical activity compared to individuals who are at a normal weight. This isn’t the first study to find that individuals who are overweight may find it harder to lose weight than their slimmer counterparts, highlighting the importance of cutting calories to shed pounds.