Geschatte leestijd: 3 minuten“I’m going to convert fat mass into muscles” is something that is often heard inside or outside the gym. Despite sounding interesting, converting the fat on your belly into muscle mass in your buttocks is impossible. Converting fat mass into muscles is one of the most persistent myths in the fitness world.
The processes of burning fat mass and building muscles
Burning fat mass, also called lipolysis, is only possible with a calorie deficit. The body demands energy for any process, while there is not enough energy available from the food consumed. As a result, fat cells are broken down to extract the necessary energy, resulting in a reduction of fat tissue.
Building muscles occurs through a complex process called protein synthesis. Simply put, consumed proteins are broken down by the body into amino acids (the building blocks of protein), which are then transported to the cells (muscle cells in this case). In the cells, these amino acids are rebuilt into protein, resulting in larger muscles.
As you can see, these are two completely different processes. The question of whether you can convert fat into muscle is thus answered negatively. The fat cells that are broken down in your belly do not move to your buttocks or biceps, unfortunately.
What might be an interesting next question is:
Can I lose fat mass and build muscles simultaneously?
As just described, losing fat mass and building muscles are two different processes. It therefore seems impossible for them to occur simultaneously. Namely, to lose fat mass, you need an energy deficit in the energy balance. To achieve optimal protein synthesis and thus build muscles, you need sufficient available amino acids in your body. However, protein synthesis decreases with a calorie deficit.
Both processes are therefore in conflict with each other. For fat loss, there needs to be LESS eating, while for muscle building, MORE food is needed.
Are there exceptions? Yes, people who are overweight and untrained are able to increase protein synthesis to such an extent that muscle tissue can be built even with a calorie deficit. Responsible for this is the positive nitrogen balance that normally can only be maintained when there is a surplus of calories consumed. People with obesity seem to be better able to maintain this positive nitrogen balance despite consuming fewer calories than are expended.
If you are still not consuming enough (how much is sufficient will be discussed later) protein, then by increasing your intake of it alone, you can achieve a higher protein synthesis.
It is also true that calories from fat tissue can be more easily used to support the building of muscle tissue. This partly explains why muscle growth can be achieved when strength training is done for the first time.
What to do?
If you have a high fat percentage and/or little to no experience with strength training and/or eat little protein, then you can lose fat mass and build muscles simultaneously.
- Start strength training where you train each (the to be developed) muscle group more than once a week. Use heavy weights and dare to train to failure regularly.
- As a woman, aim to eat about 2 grams of protein per kilogram of body weight. As a man, you can aim for 2.5 grams of protein per kilogram of body weight. Use supplements if necessary to supplement this.
If you already have quite a bit of experience with strength training and eat a fair amount of protein, then the chance is very small that you can naturally lose fat mass and build muscles at the same time. Nevertheless, the advice remains to train heavily, but make sure you have realistic expectations. For advanced athletes, the focus could best be on one hand on building muscle tissue while accepting a slight increase in body fat percentage. On the other hand, you can focus on reducing the fat mass in your body and consider that during that period you will not build additional muscle mass.
References
- J Am Coll Nutr. 1999 Apr;18(2):115-21. Effects of resistance vs. aerobic training combined with an 800 calorie liquid diet on lean body mass and resting metabolic rate.
- Am J Clin Nutr. 1997 Sep;66(3):557-63. Effects of strength or aerobic training on body composition, resting metabolic rate, and peak oxygen consumption in obese dieting subjects.
- J Nutr. 2010 Apr;140(4):745-51. doi: 10.3945/jn.109.118372. Epub 2010 Feb 17. Acute energy deprivation affects skeletal muscle protein synthesis and associated intracellular signaling proteins in physically active adults.
- J Lab Clin Med. 1977 May;89(5):1030-5. Effect of a protein-sparing diet and brief fast on nitrogen metabolism in mildly obese subjects.
