Why some people burn fat slower
Even if two people follow the same training program, one person may burn significantly more fat than the other. Disappointing for the one not seeing the desired effect. A research team has discovered what might be causing this - and it's still worth sticking with it.
Sports rev up fat burning - for some people much more than others. The reasons for these differences have now been explained on a molecular level by a research group. Newly discovered versions of a certain protein are responsible for different training effects - and could be the basis for new medications against severe obesity.
Less calories consumed than burned, and regular exercise: This simple recipe for weight loss is often presented. However, some people burn significantly more fat than others during the same training unit. It could be due to genetic makeup. Now, a Japanese research group has analyzed what happens at the molecular level during a training unit.
Protein with Key Function
It was known that the signaling molecule PGC-1 alpha plays a key role in energy metabolism - but it was unclear how exactly the protein influences this. Recently, a team led by hormone specialist Ogawa Wararu from the University of Kobe discovered that there are several different versions of this protein.
"These new PGC-1 alpha versions, referred to as b and c, have almost the same function as the common a version. However, they are produced in muscles ten times more during physical exertion, while the a version does not show such an increase," Ogawa is quoted as saying in a statement from his university.
Less Energy Consumption during Movement
Kobe and his team suspect that the newly discovered versions of the signaling molecule regulate energy metabolism during training and thus also influence whether someone is obese or not. To test this, they bred mice lacking the b- and c-versions of the protein but not the a-version. Then they put the mice on a running wheel and recorded muscle growth, fat burning, and oxygen consumption in the resting state, during short training sessions, and six weeks after regular exercise.
They found that the absence of the b- and c-versions of PGC-1 alpha led to the mice using less oxygen during and after training and burning less fat. "In mice lacking these variants, energy consumption during beta-activity is impaired," according to the scientific journal "Molecular Metabolism." This would contribute to the development of obesity and hyperinsulinemia - that is, high insulin concentrations in the blood.
Similar experiments were conducted by the research team with 20 people: 10 men with Type 2 Diabetes and 10 without, who had to pedal on a stationary bike. The researchers also found that the test subjects used more oxygen and had less body fat the more they produced the b- and c-versions of the signaling molecule. This observation applied to both men with Type 2 Diabetes and those without the condition. "The hypothesis that genes in skeletal muscle determine obesity susceptibility was therefore correct," Ogawa concludes.
Persistence for Muscle Growth
So, does this mean that people who genetically produce less b- and c-versions of the protein should not even start exercising to support weight loss? The study cannot answer that - it suggests, however, that more patience may be required in such cases.
According to a research group's observation, regular movement over a longer period of time stimulates the production of the standard version of PGC-1 alpha - that is, the a-variant. At least in mice that trained daily for six weeks, muscle mass increased, regardless of whether they produced the b- and c-versions of the protein.
For Ogawa and his team, their study provides clues for new obesity medications. "In recent times, medications against obesity have been developed that suppress appetite and are increasingly prescribed in many countries worldwide. However, there are no medications that treat obesity by increasing energy consumption," emphasizes the hormone researcher. If a substance were found that increases the b- and c-versions of PGC-1 alpha, this could lead to the development of medications that increase energy consumption during sports or even without sports. "Such medications could possibly treat obesity independently of a diet," so Ogawa.
Despite genetic differences, maintaining a calorie deficit and regular exercise are still essential for weight loss. New research reveals that variations in a protein called PGC-1 alpha can significantly impact fat burning during exercise, with some individuals producing more of the beneficial b and c versions.
Individuals with less production of the b and c versions of PGC-1 alpha may require more patience during weight loss efforts, as regular exercise has been shown to stimulate the production of the standard a-variant, promoting muscle growth over time.
