Blood sugar levels and insulin
With the rise in blood sugar levels, the carbohydrates have indeed arrived in the energy system of the body arrived, but cannot be used. For further utilization of glucose, a hormone called “insulin” (which is formed in the pancreas) is subsequently required.
Insulin is always released when the blood sugar level rises. The effect of insulin is that it makes the blood sugar levels drop again. It thus provides a regulatory mechanism in the energy metabolism. The amount of insulin secreted is significantly greater with a high rise in blood sugar levels by foods with a high GI than with foods with a low GI and thus lower blood sugar. Incidentally, a high level of insulin usually causes the blood sugar level to fall below the baseline level even in the case of a sharp increase. This is also the explanation of why you often get tired of junk food or sweets.
The main task of insulin is, in addition to the regulation of blood sugar levels, the supply of cells with energy. In addition to glucose, the energy used for this purpose can also be provided by fat absorbed from food.
If there is an oversupply of glucose and fat and the energy stores are already full, the excess nutrients are stored in the fat cells. This is a protective mechanism of the body that has outlived all of evolution and is designed to help people withstand even periods of low nutrition: in good times, accumulate nutrients for the bad days. No one could anticipate the constant abundance of nutrients in the affluent society today.
This also leads to a very simple rule, which states that foods that have a high GI and thus lead to a sharp increase in insulin levels, should under no circumstances be combined with fatty foods. This oversupply leads to a direct filling of the fat stores and thus, especially in people with a slow metabolism, faster gains in the love handles department.
Insulin is also an anabolic hormone because it carries the nutrients into the cells where they are needed. Without insulin, there is no muscle gain. This is also the reason why purely ketogenic (i.e. extremely low carbohydrate) diets in the long run bring much less success in bodybuilding. The only exception to this is the “anabolic diet” or “carb cycling”, in which there is a periodic refeed with carbohydrates.
The antagonistic hormone to insulin is glucagon. Glucagon attacks glycogen and fat storages in the human body and leads to a release of glucose, increasing blood sugar levels.