Why Not Everyone Loses Weight the Same Way

Same hours, same workouts. But some people lose more pounds, while others have to work twice as hard. According to a study conducted by researchers at Kobe University in Japan, the reason why some people lose weight more slowly than others lies in its ability to produce certain key molecules. The results of the study were published in the journal Molecular metabolism They may be useful in the treatment of obesity.

Some people find it much harder to lose weight than others, which calls into question the linearity of the concept that weight loss or gain is simply “calories in minus calories out.”

In the past, the scientific community identified a protein called PGC-1⍺ that appears to link exercise to metabolic energy. However, it was not yet clear whether more of this protein produces these effects or not. Now, experts have discovered that there are actually different versions of this protein. “These new versions of PGC-1α, called ‘b’ and ‘c’, have almost the same function as the ‘a’ version, but are produced in muscles ten times more during exercise, whereas the ‘a’ version does not show such an increase,” explained study author Ogawa Wataru.

The real culprits

To demonstrate that “b” and “c” regulate energy metabolism during exercise, the researchers experimented with mice that had these latest versions (as well as those that produced the first) and measured parameters such as the rodents’ muscle growth, fat burning, and oxygen consumption during rest. They then subjected some human participants to similar tests.

Mice with the “a” version consumed less oxygen during exercise, burned less fat, and were prone to weight gain. In studies applied to humans, the researchers found that the more of these versions they produced, the more oxygen they consumed and the less body fat they had. In addition to muscle production, the team looked at how the production of different versions of PGC-1⍺ changed in fat tissue, but found no significant effects in response to exercise, only in relation to cold.

The scientists concluded that the lack of alternative versions of the PGC-1 protein⍺ “b” and “c” means that the body is essentially “blind” to short-term physical activity, consuming less oxygen and burning less fat during and after exercise.

Against obesity

Understanding the physiological activity of different versions of PGC-1⍺ could lead to new therapeutic approaches to combat obesity. The team is currently conducting a new study to better understand the mechanisms that lead to increased production of versions “b” and “c” during exercise.

“Anti-obesity drugs that suppress appetite have recently been developed and are increasingly prescribed worldwide. However, there are no drugs that treat obesity by increasing energy expenditure. If a substance that increases the number of variants ‘b’ and ‘c’ were found, obesity could be treated regardless of dietary restrictions, with or without exercise,” Wataru concludes.

The article was originally published in WIRED Italy. Adapted by Alondra Flores.