Muscle or fat: which one is heavier?

Why do fat mass and muscle mass not weigh the same? Where does this difference come from, which is important in terms of a person’s silhouette? It’s revealed just underneath.

The weight difference between fat and muscle

Most people think that doing sports they will lose weight. However, after a few training sessions and a first look at the scales, they realize that the kilos they thought they had lost have increased a little! If they are surprised by this result, it’s because they don’t know very well how the human body works and the muscles or fats that make it up!

The role of fat and muscle mass

Fat is primarily a semi-solid mass found under the skin and around the kidneys. Its role is to be a reserve of energy, protection against cold and shocks. Too much fat is bad for your health, however, it is necessary for the control of growth, reproduction and other mechanisms of human metabolism.

Muscles, on the other hand, are organs in the form of fibers that have the power to contract and shorten. There are three types of muscles: the heart, which contracts involuntarily and is under the influence of hormones, the stomach muscles, which also contract involuntarily, and the skeletal muscles, which are attached to the bones and allow the body to move.

Why is there a difference in weight between fat and muscle mass?

The difference between fat mass and muscle mass is in the density. Thus, fat mass is more voluminous than muscle mass. At equal weight, fat takes up more space in the body than muscle. Muscle is made up of 75% water, 20% protein and 5% fat, carbohydrates and other minerals. It is therefore important to know your body composition if you want to lose weight.

With a physical effort the muscle fibers thicken and the muscle becomes harder. A muscle mass that is regularly trained with heavy loads consumes a lot of energy and calories, even at rest. The greater the muscle mass, the more it is naturally regulated by drawing from the fat mass.

Many beginner athletes think that the more they sweat the more fat they lose, this is not true! They lose water and become dehydrated! It is during muscle recovery that fat starts to disappear!

What are the consequences of your shape?

Because muscles take up less space in the body than fat, two people can weigh the same and look completely different. Weight training is a perfect example of how you can become heavier but thinner.
Depending on the practitioner’s goals, the body can be shaped to have a slimmer waist and a flatter stomach, wider shoulders and well-defined pectorals. The muscles are more imposing, heavier, and yet the sportsman has lost one or two sizes in his clothing! The body has changed shape, it has become heavier but has become slimmer! Therefore, at equal weight, two people can have a different physical appearance.
Sean Stanton
Sean Stanton

Sean Stanton nutrition professor at Gurze is in charge of nutritional support. He graduated with a Master in dietetics and human nutrition with a specialization in the care of high-level sportsmen from the King's College London. Sean has also developed his freelance activity through home consultations or by videoconference.