Fat cells and muscle cells might look nearly the same from the outside. They’re both part of your body and just below your skin. They both even can be clenched with your fingers. The muscles might be a little bit harder to clench – but this isn’t too much of a difference, am I right?
Yet, it is. I remember back when I first started working out, with an obsolete, rusty barbell at my friends place. I was sixteen years old. Back then I told my friend: “I don’t want to get any skinnier. I just want to convert my fat cells into muscle cells!” I was being serious. Me and my friend both thought it was a reasonable goal. It wasn’t.
I’ve wasted countless of hours on trying to build muscle mass while simultaneously losing fat. It wasn’t worth it. Here’s the unparalleled reason why.
Fat Cells: Old Friends – New Enemies
Fat cells used to be our friends. Back in the days of our ancestors, when food were scarce, we had to be able to massively store energy. Nobody in the tribe knew when we had to go weeks without food. That’s the reason why our body is inclined to store fat and minimize muscle growth. Our body is conditioned to be an energy storage machine and not an energy waster.
How To: Fat Cell
The fat cell is divided into multiple parts. There is the purple nucleus, the green mitochondria, the blue Golgi apparatus and the yellow, gigantic, fat storage unit. The last part is what makes the cell full of lipid unique. The fat cells are your body’s energy storage.
Fat cells participate in hypertrophy. Which means they increase their fat storage until they can’t physically increase in size anymore. Then your body creates more fat cells. You want to keep the amount of fat cells close to the optimum in your body. Because the fat cells in your body are yours to keep for a lifetime. The storage inside your fat cells can be lost. But fat cells, after they’ve been created, immediately get replaced after their death.
Even worse: Fat cells produce a protein, that inhibits your body from breaking down the fat storage. Your organism creates a set point. This means that once you’ve been overweight it’s far easier to reset into your old, unhealthy habits again. That’s the reason why 40% of obese children become obese adults.
If we apply this knowledge to dieting, we know that it’s crucial for you to keep your diet sustainable. Because if your diet isn’t, your body is more than happy to keep adding the lost fat again to your organism. This is called the Yo-Yo effect, which has been shown to increase all-cause mortality.
Fat cells also have other crucial factors. They’re turning androgens into estrogens. They’re contributing to the production of estradiol. This is not only bad for men, as we want to be full of testosterone. But this is also bad for women, as it’s a major risk factor of infertility.
How To: Muscle Cell
Muscle cells look quite differently than fat cells. They’re also quite different in their functioning. Muscle cells are the individual contractile units within a muscle. A muscle in your body, like your biceps, contains hundreds of thousands of muscle fibers.
The contraction of your skeletal muscle fibers (muscle fibers are a synonym to muscle cells) lead to a movement in your joints. The main task of your muscles is to move your body. In comparison to fat cells, muscles don’t store energy, they need energy for their functioning.
When muscle cells are contracting, they’re releasing myokines. This is the way muscle fibers communicate with the rest of your body. Myokines affect most organs, but are famous for their interaction with the glucose and fat metabolism. Which means the muscles are communicating with your liver and your fat cells, to release glucose and fats in the blood stream. This is energy for the muscle cells to use. This effect of the myokine regulates glucose and lipid metabolism and therefore counteracts inflammation. This may help slow down aging.
The Starting Point
The anatomy and the function of fat- and muscle cells are vastly different. Due to this reason, it’s physically impossible to convert fat cells into muscle cells.
If you’re just starting out and aiming for a better body, do this: Eat one extra portion of vegetables for dinner and go for a 10-minute walk afterwards. This is easily doable – and that’s a huge advantage. The average gym-goer quits after 3 months. The reason: He didn’t build a fundament of healthy habits.
If you don’t have 10 minutes, you don’t have a life. – Tony Robbins
 ^ Green BB, Weiss NB, Daling JR: Risk of ovulatory infertility in relation to body weight. Fertil Steril 50:721, 1988