I don't eat much, but my weight is still the same – why?

As a dietitian, I often meet people struggling with excess body weight. What's interesting, vast majority of those people try to explain such situation with atypical genetic conditioning reflected in the following statement: “I really don't eat much, and I still weigh the same, besides – you can see me...” Because of the fact that this phenomenon is so common, it's worth taking a closer look and trying to reveal the mechanisms causing it, as well as – diagnose its source.

What does “I don't eat much” mean?

There's no doubt that the expressions, like “much” or “a lot” are extremely imprecise. They relate to the individual imagination and, without proper reference points, they say almost nothing about the real supply of energy (relating to the body's expenditure) and quality of food. Whereas, these two aspects are the key factors for the body mass and composition. In order to visualize how much misunderstandings may be related to this matter, I would like to present an exemplary menu of a person who states that “doesn't eat much”.

The minimalist's diet

Matt came to my office with stage I obesity. He was 173cm tall, he weighed 93 kg and he had 102 cm in waistline. He used to workout and now he wanted to start doing that again, but so far, he lacked time. Matt was one of those people who thought they didn't eat much. However, his exemplary menu looks as follows:

Breakfast: 1 wholemeal toast with margarine “for cholesterol” and low-sugar jam. As an addition, 200ml of strawberry yoghurt with lowered amount of fat (1%) and before going to work – 1 glass of vitamin multi-fruit juice.

Second breakfast: small piece of cheesecake and coffee with cane sugar.

Dinner: small portion of spaghetti with salads and a bottle of one-day apple juice in a cafeteria.

Dessert: homogenized vanilla cheese (not to be so hungry), 1 small apple.

Supper: 1 slice of bread with margarine and yellow cheese, pickle, 1 boiled sausage (about 120g). A glass of vitamin multi-fruit juice.

Beverages: additionally, Matt drinks 1 energy drink during a day (on his way to work), 1-2 glasses of juice (always 100% without sugar) and after dinner (he cannot resist that) 1 or 2 bottles of beer.

Matt, as I mentioned before, thinks he doesn't eat much, at least for his size. He tries not to eat as much as to be completely full, besides, he can see how other people from work eat more, even some chocolates, or order two-course meals. Whereas, he never eats until full stomach (“just tell me – what is this one slice of bread for an adult man, and I just eat that for breakfast”), he tries to eat main meals only, and he just allows himself for “a piece of cake with coffee” for second breakfast. When I asked him about nutrition mistakes, he points at the cheesecake, sausage and beer without any hesitation and he admits that if I tell him to resign from those products, he will listen to me.


Unfortunately, the truth is, Matt eats a lot of food and he probably doesn't have the “evil gene” which causes his obesity. The real energy value of the menu mentioned above (including beverages) is about 3000 – 3200 kcal. Matt's energy demand is not higher than 2500kcal. So, excess amount of body fat is just a simple consequence of excess supply of energy and inappropriate choice of food. It is also significant that Matt eats over half a cup of sugar, mainly from beverages that he drinks. Resigning just from all the liquids and drinking water, sugar-free coffee and tea instead, would cause lowering the energy supply by about 600kcal! Let's add 2 – 3 workout sessions a week in a form of strength training and Matt could easily lose weight without changing his diet...


Of course, specific genetic conditioning, as well as some diseases, may cause that even with relatively low supply of energy, it will be difficult to lose weight. However, practically speaking, subjective beliefs resulting in expressions like “I don't eat much and my weight is still the same”, have nothing to do with reality. The problem of underestimation of daily energy supply is very common and it concerns vast majority of people suffering from overweight and obesity. Only scrupulous counting the energy value of the daily menu reveals the truth about the real cause of the problem with excess body weight.