There is fat throughout our body and we must assume this, in the same way that we must assume that much of it has necessary functions for our body and therefore we must not criminalize it. Obviously, as in so many cases, excess is what hurts us. This is why today we eviscerate ourselves – not literally – in an exercise in biology to find out who we can remedy and who we cannot.
Because, apart from something that worries us and that usually leads us to dietitians, nutritionists and doctors, what is body fat ? Well, first we must say that, as in so many things, there are essential parts and non-essential parts and our body, and fat, are not alien to them.
Then we have to be clear about what we need it for, although above all we should call it adipose tissue, one of the many tissues in our body, made up of cells that accumulate lipids. Their elemental functions are mechanical, that is, they cushion, protect and keep the various structures of the body in place, be they organs, muscles or bones, so we could say that they are a kind of separators. In addition, its other great function is metabolic, since it generates and stores energy for our body.
Once we know that we need it and that it is both ‘shelf and fuel’, we must bear in mind that not all the fat in our body is the same. To begin with, you have to distinguish between essential fat and non-essential fat. The first is what we need for our normal physiological functions, which normally ranges between 3% and 12% of total body weight. So to speak, let’s say that if we were a car it would be our ‘reserve’.
From there we could have the ‘full tank’, which would be non-essential fat and which has ratios between 10% and 22% in men and 20% and 32% in the case of women. It goes without saying that the higher these values, the more we will be tempting luck with diseases related to obesity such as diabetes, cardiovascular risks, hypertension and certain types of cancers.
Knowing this, there are still more margins for different examples, so we cannot get bitter when we do not lose weight as much as we would like or it does not disappear from unsightly places because, dear readers, not all the fat in our body is distributed in the same way or has the same function.
Body fat depending on its location and use
In this way we arrive at the three main types depending on their location: hard, soft and intermuscular, which we will soon face. In the case of the first, also called visceral, it is the one that covers the different organs, so it is focused on the abdomen and thorax. As you can imagine, it is complicated to eliminate -and also to achieve-, but also the most dangerous because to reach a high level of hard or visceral fat we must have committed certain excesses. A high presence of this is related to the aforementioned heart diseases and diseases.
Different is the case of soft fat, also called subcutaneous or peripheral, which no longer has the mission of protecting our organs, but is found under the skin, being the outermost layer. Here we are already going to fats by all known as the one that accumulates in the belly, hips, chest or buttocks. Interestingly, in the case of men it focuses on the belly and abdomen, while in women it goes to the legs, hips and buttocks.
This, which may seem unfair or arbitrary, is due to a biological and physiological reason: these areas act as energy reservoirs for a hypothetical lactation. For this reason, when you gain weight and say “all the kilos are going to my ass or hips” it is for a biological reason: the woman’s body acts as a natural reserve. It is this that we refer to as the one that we can combat constantly with exercise ( even walking ) or with dietary precautions.
Finally, in this category, we find a third class, the intermuscular, which is residual in total terms and is found among the various fibers of the muscles and, in case of overweight, it is more noticeable.
White fat and brown fat: what are they and what do they do?
However, not only does it matter where it is located, but also what our body uses it for and why there are fats that we cannot lose, even if we strive, and others that help us keep the body in shape. Therefore, we must speak of two types of fat in functionality: the brown and white.
In the case of the first, it must be said that it has a thermogenetic function, that is, it creates heat, which is why it is very abundant in newborns (up to 5% of the total weight of the baby’s fat) and decreases according to growing. It is also eminently visceral, since it surrounds the renal and carotid arteries, in addition to the thyroid gland and the mediastinum, as well as being present in the axillary area. It basically serves as a ‘stove’ in response to the cold outside.
For its part, brown fat is more present in newborns, where it accounts for 5% of total body fat, and its percentage decreases as we grow older. The brown is located mainly around the renal arteries, the mediastinum, the carotid arteries, the thyroid and in the axillary area.
On the other side of the scale, we almost literally have to talk about white fat. It already covers the vast majority of our body fat , being able to assume the percentages mentioned above and is, fundamentally, a reservoir of energy. As such, they act by metabolizing themselves to obtain cellular food in the form of glucose. This is where we can get down to work to reduce its amount, especially through exercise and diet, looking for the famous caloric deficit: eating fewer calories than we expend and thus avoid gaining weight .
In discord we could talk about a third fat, baptized as beige fat, which covers a new field of research and that is halfway between the two, being closer to brown fat, since it would help us burn energy instead of storing it . It follows from it that certain hormones and enzymes that we release in our body in times of stress, tension or cold, would serve to convert that white fat into beige fat.