The fact that being overweight is correlated with multiple health risks is, I think, clear to most people by now - at least in our fitness scene. People with high levels of body fat often have an increased risk of developing diseases such as diabetes and the probability of having a heart attack can also increase.
In addition, the strain on the joints can be very high because the heavy weight has to be constantly dragged around. Many people's testosterone levels are also lower if they weigh more - for both men and women.
The fat acceptance/body positivity movements have become increasingly influential in America in recent years, and the expression "healthy at any size" has also become quite well-known. While it is certainly true that people of any size can exercise and eat nutritionally rich foods, this does not mean that your weight is never relevant to your health. Many people would definitely be doing their health a favor by losing weight. This is probably nothing new for you.
"Health at every size" does not mean your weight is irrelevant to your health!
Too low body fat percentage
But it can also be VERY unhealthy if you have a very low level of body fat, even though many people are not as aware of this fact. We're not talking about people with anorexia, but about well-trained people with a very low body fat percentage, a good muscle mass, and an actually quite nutritious diet.
"Actually" healthy diet, because to be really healthy, they would have to eat more, so that they accumulate some fat reserves and then feel better. Whether or not we have adequate fat reserves is absolutely crucial for how good or bad we feel and how healthy we are.
A too low body fat level can be very unhealthy, EVEN IF you are trained and eat a balanced diet!
Imagine a bodybuilder named Mark with 5% body fat. So visually, he is made up of nothing but muscle. The essential body fat level is about 3% for men (for women it's about 12%). This body fat is - as the name suggests - essential for our body.
If we lose some of it, we may simply die. This essential fat is present, for example, in nerve tissue and organs. Mark has 5% body fat. 3% is essential. I.e. he has only 2% body fat for his RESERVES, which he could still lose without dying.
If we now assume that he weighs 200 lbs, then that is 4 lbs of fat reserves. That's not very much at all! In terms of calories, that's about 14000 calories. If he were to diet now in a deficit of 7000 calories per week, then after 2 weeks he would have no more body fat reserves and would probably not live long - THEORETICALLY.
When we run out of body fat reserves, we die!
In practice, however, this would probably result in his body doing everything it can to reduce calorie consumption. How does the body do that? By making Mark as listless as possible, so that he doesn't move much, and also by reducing all metabolic processes in the body as much as possible.
Then Mark with his current diet may no longer come to a deficit of 7000 calories per week, but rather something like only 3500 calories. That would then keep him alive for a longer time.
But even if he were eating on maintenance calories, at such a low body fat percentage he would be in a totally unhealthy state. He would be listless, anemic, and have a super high food focus, while his testosterone levels would be catastrophically low (if he wasn't supplementing testosterone from outside sources).
His low testosterone level would then certainly also result in a low libido; his body thinks there is a famine going on, and if he doesn't even get enough to eat to keep some fat reserves, why would he have a high reproductive drive? His children would starve anyway.
And here we can't just say "time heals all wounds, he just has to get used to the low body fat." No, he will probably NEVER live a healthy and energetic life with this low a level of body fat. His fat reserves are simply way too low. His body has no buffer to allow him to survive a famine that may actually occur.
With very low body fat, the body will do everything it can to not lose even more: Lack of energy, lack of strength, lower basal metabolic rate, low libido, etc.
So, that was of course a super extreme example, but extreme examples often illustrate a situation quite well. The point at which your body rebels and screams for more food is very individual.
There are people who have a six-pack and striations everywhere all over the body who nevertheless have absolutely no health problems as a result; they are fit and strong and have a super well-functioning hormone balance.
Then again, there are people who are already experiencing negative consequences if they have even a slightly visible six-pack. But what definitely applies to all people is that a stage-ready physique (in terms of leanness) cannot be maintained healthily in the long term.
By the way, this mostly applies to people with a very lean body, and should not discourage people with a high amount of body fat from losing weight. Anyone who is overweight and would benefit health-wise if they lost weight should do so without worrying about this!
This is only really about people with very low body fat, at the point where the body begins to rebel. And the point at which your body fat percentage is "very" low depends on you as an individual. You have to find out for yourself and then - for the sake of your health and quality of life - aim for a weight at which you feel good.
The point at which body fat is "too" low varies from individual to individual: for some, it is only when they have striations all over and for others it starts when they have only a slightly visible six-pack.
Now I want to tell a little personal story - namely about my own experience with a very low level of body fat.
4.5 years ago I started a diet for a bodybuilding competition. I had to lose 35 lbs and had taken 32 weeks to do so. So that was an average of just over a pound per week.
The first period of the diet was pretty easy. I had a big goal in mind that motivated me - namely to present my best form on stage - and I could still eat 3500 calories. My actual intake was around 4000 calories.
Then, of course, as the diet progressed, it gradually became more difficult. This is quite normal. As I explained above, the less fat reserves you have, the more your body rebels.
This manifested with me becoming a bit more listless and my food focus becoming a bit more pronounced. As I said... quite normal and nothing I wasn't aware of in advance. Towards the end of the diet it became really brutal: super listless, huge food focus, low libido, and also very low power in the gym.
But I didn't think about giving up, because I would describe myself as a person who can just grit my teeth when I have a big goal in mind.
But when the competition was over and the big goal was gone, I realized how poorly I was doing physically (and also mentally).
The first two days after the competition I ate whatever I felt like and in the quantities I felt like. By my rough estimate, that was about 10000 calories per day. That was no "special achievement." I could actually have eaten more, and a few of my fellow competitors did the same.
After these two days I counted calories again and ate in an aggressive surplus of 500-1000 calories per day. I had planned it that way in order to build up some fat reserves again, in the hope that I would feel better again quickly. Of course, I did build up fat reserves, but I didn't really feel any better.
I then thought to myself, "Well, I'll just have to go a few more weeks... then I'll be fine." But even after 3/4 of a year, by which point I had put on almost as much fat as before the diet, I still didn't feel any better.
Then I went to the doctor and had extensive blood work done. The results showed that my testosterone level was virtually non-existent and that some other important values were also not within the normal range.
So I was far from being healthy again. But my family doctor didn't really know how to deal with the problem either. After that, I saw a few other doctors and finally got a year of testosterone replacement therapy recommended by an endocrinologist.
His rationale was that we should give my hypothalamic-pituitary-adrenal axis a little time off by externally supplying a small amount of testosterone over a year.
That way, the body wouldn't have to produce that testosterone itself. Our hope was that after this time off with a "rested" axis, my body would produce testosterone again on its own.
So that's what we did. I received a testosterone injection every 6-8 weeks. This was the equivalent of the amount of testosterone a healthy man produces himself. That is the difference between doping and testosterone replacement therapy.
With doping, you add more testosterone than you would produce yourself, whereas with replacement therapy, you just replace the amount that your body should be producing itself, but is not.
Despite side effects like the acne and the mood swings, I also felt much better shortly after starting the therapy.
I suspect that these side effects occurred because there are large fluctuations in testosterone levels with a typical replacement therapy like the one we did, which used infrequent injections. The best type of replacement therapy, however, is another topic.
So I was doing really well during the therapy. Then after the therapy I fell into a bit of a slump. That is quite normal. The body is used to having testosterone being added from the outside and not having to produce it itself. It takes a while for the body to realize that nothing is actually being added from the outside anymore.
Fortunately, my body settled down after about half a year in such a way that I was producing testosterone myself and feeling great again. That's not something that can be taken for granted, by the way. Many people remain on testosterone replacement therapy for the rest of their lives.
Was this therapy necessary for me at this point? I can't say, because I don't know what would have happened if I hadn't done it. Maybe my own testosterone production would have started up again on its own if I had waited more than 3/4 of a year, and had instead gone 1.5 or 2 years, but maybe not.
In any case, it took or would have taken a very long time until I felt really well again and was healthy.
Excessively low body fat can lead to unbalanced hormones, which take a long time to recover from.
Why am I telling you this? I want to show you that dieting down to a level of leanness that is MUCH too low can have real long-term consequences for your health and well-being. You just have to be aware of that.
Especially now that the sport of natural bodybuilding is becoming so popular, I see more and more young athletes who have similar problems as I did back then.
For some, this normalizes relatively quickly after the end of the diet, when they gain weight again, but for some it takes a very long time until everything works normally again. By the way, this is sometimes even worse for women than it is for men!
Now you could of course say: Yes, but it also depends on how you diet. If you do everything right during the diet, then it's not so bad.
There is some truth to this: if you diet slowly, take diet breaks, cover all your micronutrients, eat enough fat, etc. then you will DEFINITELY be better off at the end of the diet than someone who does none of this.
Nevertheless, after the diet you will have a super low body fat level, which in itself - even detached from the way you got there - is simply very unhealthy. You will have hardly any fat reserves left and your body won't like that. Period. And that's a good thing, so that you don't get any stupid ideas, continue dieting, and then really die.
A too low body fat percentage is unhealthy - even if you design your diet PERFECTLY!
The moral of the story here is that if you want to achieve a very low body fat level for yourself (e.g. for a competition or a photo shoot), then be aware of the potential consequences for your health.
In addition, after the diet, you should not try to maintain this low level of body fat. Eat in a slight calorie surplus until you reach a level where you feel more comfortable again.
And that doesn't have to be 20% for men or 30% for women. It may well be that you feel great if you have 10% as a man or 20% as a woman and still have a six-pack.
However, it is very unlikely that you will feel comfortable if you are lean enough to have, say, striated glutes. Besides, it's also quite uncomfortable to sit on striated glutes - especially if you often sit on an unpadded chair!
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