Some time ago I talked to a woman – Alice. She asked me for help because she has a problem to maintain her body weight. It leads to the emotional roller coaster, frustration and resignation when her weight increases, and hope when it decreases. Alice tried every possible diet: fluid, low carb, low fat, raw food etc. Every time she lost weight, but after that, the weight quickly restored with some extra pounds. She persistently claimed that she did not eat much, yet she cannot keep the lower weight.
The story above applies to the major part of the society in highly developed countries. I am trying to keep the proper body weight as well, and it is not easy. That is why I understand those, who cannot deal with the problem of overweight and obesity. I came up with the idea to figure this out. Why does Alice gain weight, even though she does not eat much? We together decided to have her RMR (Resting Metabolic Rate) tested to find out how many calories are burned during her rest. In other words, the amount of energy that is used for biochemical processes which occur in an organism like brain activity, breathing, muscle building, fat storing, digestion, blood circulation etc. The test has revealed that Alice’s body burns fewer calories during the rest, that it should, as her muscle tissue is low, while body fat is high, especially visceral fat. White adipose tissue, or white fat, is located in the abdomen and it covers internal organs.
What has caused these results? The answer is easy. Alice is 45 years old and she always tried to stay fit. It was not easy, and continuously became harder. Her diets reduced the number of consumed calories, and it led to the fat loss, but also muscle loss due to gluconeogenesis. When the diet was over, Alice gained weight, mainly white adipose tissue and not muscles. This resulted in slower RMR (Resting Metabolic Rate), as the white adipose tissue is not metabolically active, because it serves only as fat storage in the form of triglycerides.
Our body has another type of fat tissue too – brown adipose tissue or brown fat. It is rich in mitochondria, and it is metabolically active. It takes part in the thermogenesis process, the heat production in organisms. Subsequent Alice’s diets led to a weight loss by muscle tissue (during diets muscle tissue may become the source of glucose, so energy, in gluconeogenesis process) and white fat reduction, both in comparable amounts. However, when Alice gained weight back again, it was mainly fat tissue, not muscle. Next cycles of losing and gaining weight worsened the problem and caused the disturbance of proportion between muscle and fat tissue. It slowed down her metabolism, as the loss of muscle tissue lowered the possibilities of the body to burn nutrients. This situation shows that one of the causes of overweight and obesity occurs when we periodically start diets to reduce body weight.
Our organisms, due to evolution, was shaped to work in high efficiency. To obtain as many nutrients from food, which then can be used to produce energy, for example, Adenosine triphosphate (ATP) in mitochondria. But what if we have 40% of fat tissue, from which only the brown fat is metabolically active? We have lower capacities to use the energy we ate, in comparison if we had for example 20%. That is why men, who have more muscles than fat, usually have a slightly faster metabolism.
Each diet cycle and weight gaining decreases not only the ratio of muscle tissue to fat tissue but also it lowers the muscle tissue mass. After that, each cycle reduces the ability to process food for energy. The fewer muscles we have, the slower metabolism. That is why in this certain case we should eat less. Otherwise, the excess of energy (“fuel”) which we get from food, instead of being burned, it will turn into fat tissue.
All the above is true when we do not combine the diet with exercising, so we do not care for our muscles. That exactly was Alice’s case. Her cycles of dieting and weight gaining slowed her Resting Metabolic Rate, and because she did not exercise, her ability to burn the energy from food was lower and lower. To avoid weight gaining, she should eat less after each dieting cycle, the amount her organism can utilize.
Are the statements like “Eat less, exercise more”, “Stop eating so much, and you will lose weight”, “You do not have a strong will” valid in Alice’s case? That is what I thought, but now I have a different view, as I fight to keep the proper body weight too.
The truth is, that no one wants to be fat. Yet, the percentage of overweight and obese people in highly developed countries is still increasing. What should worry us the most is the fact, that more often it affects children and youth.
There are many definitions of obesity and overweight. In general, it occurs when the body weight is bigger than the one which is considered good for our health. Moreover, it is a chronic state defined as the excess of fat tissue. A certain amount of fat is necessary to store the energy, heat isolation etc. Yet, the excess may result in many dangerous diseases. Even more dangerous is the excess of visceral adipose tissue, located in the abdomen.
What determines overweight and obesity? The Body Mass Index (BMI). The formula is:
Since BMI describes body mass to body height, there is a strong correlation between this index and body fat of the adult.
Nowadays, and it is right, the more important index of risk than BMI is the abdominal circumference. It is logical, especially when we know that the abdominal fat, in particular, the visceral adipose tissue, is the main focus of inflammation and may even cause cancer (for example prostate cancer). Moreover, the in case of visceral adipose tissue, we do not have to be overweight or obese at all. The excess of the fat tissue may not always be seen with the naked eye. It may turn out that you are sick, and you are not even aware of this fact. In this situation, BMI will not indicate overweight or obesity.
It comes to that especially when the muscle tissue is low. The cause of this is the lack of regular physical activity that strengthens muscles. It is worth to have your muscle and fat mass tested, especially the visceral adipose tissue. It is important to know, that the upper border of the proper fat tissue level is around 25% of body weight for men, and 30% for women.
We can say, that the main problem is the lack of knowledge of how to control our metabolism and body weight. Even if we had that knowledge, the cause of the obesity is very difficult to understand. The human body is very complicated, and it is not easy to state why a person has problems with weight. What more, in nutritional science there are two paradigms of obesity. One is the theory of calorie balance, the second is the hormonal explanation, known as carbohydrate hypothesis, or insulin hypothesis. According to the second theory, obesity is the effect of a body’s insulin excess due to high carbohydrates consumption. Calories of consumed food do not matter in this case.