As problems of excess weight and obesity are becoming increasingly widespread, both a collective and individual effort is needed. For a serious approach to solving the problem, we need to act by changing our lifestyles, adopting a healthy diet and performing regular physical exercise. It is important to rebalance our energy levels, on the one hand moderating our calorie intake through our diet and, on the other, increasing the calories burnt by being active.
However, it is crucial that we also pay attention to the processes at the core of the formation of fat stores, for which not only the quantity of calories consumed is important but also the quality. The role of the fluctuations in blood glucose levels throughout the day, following consumption of carbohydrates, is particularly important. Carbohydrates, also known as glucides, are digested and transformed into glucose in the gastrointestinal tract. After meals, particularly if they are excessively rich in carbohydrates, the concentration of glucose in the blood (glycaemia) rises.
The increase in glycaemia stimulates an important gland in the digestive system, called the pancreas, to secrete the hormone insulin, which travels in the blood to all body tissues.
- favours the use of glucose by all the cells in the body;
- stimulates the storage of excess glucose in the form of fat, in particular triglycerides, in the fatty tissue (lipogenesis);
- inhibits the mobilisation of fats from the fatty stores (lipolysis) when the abundant availability of glucose make the use of energy reserves unnecessary.
Insulin, therefore, manages situations in which there is an abundance of energy resources, encouraging storage of the excess in fatty stores and blocking the use of reserves.
This is why insulin could also be thought of as a “hormone for excesses”.
Insulin then allows blood-sugar levels to be brought to normal concentration levels, both by making cells use it to produce energy, and by causing the excess to be stored as fat.