What's a big reason why being overweight is harmful?

Overeating increases the immune response. This increased immune response causes the body to generate excessive inflammation, which may lead to a number of chronic diseases. It is therefore important to keep a balance. Too little and too much nutrition may both upset the immune defense system and increase the risk of disease.

Storage of energy causes an inflammatory reaction. The explanation lies in the close connection between the body's immune system, energy conversion and the way in which we store energy. Humans are not made to eat so much. We are intended to toil for our food.

Overeating causes stress to the mitochondria. The mitochondria are the cells' powerhouses, converting fatty acids to energy. When the cells receive excessive energy, the system starts to falter. Long-term stress on the mitochondria causes low-grade chronic inflammation over many years. When damaged mitochondria accumulate, the immune response is activated. This immune response is what causes the inflammation.