Role of insulin and carbohydrates in weight gain

Digestion of carbohydrates

What will happen when we eat a food containing carbohydrates, eg starch? Firstly, during chewing, a portion of the starch is hydrolyzed (digested, cut into small pieces) with amylase enzyme in saliva. Then the food reaches the stomach. It is gradually pushed into the intestine through the pylorus (closure of the stomach). In the small intestine, enzymes continue to attack carbohydrates to leave only single molecules, monosaccharides. The glucose is released and absorbed into the blood.





Glucose and insulin

Following the ingestion of carbohydrate food, such as after a meal or snack, the blood glucose (blood sugar) increases. At time T we can burn this glucose to a relatively intense effort to think (the brain consumes a lot of glucose), or to rebuild glycogen stores in the liver and muscles (storage form of glucose). High blood sugar is toxic to the body, that is why intervenes insulin, a hormone secreted by the pancreas. This hormone is hypoglycemic, that is to say, it lowers blood sugar for a return to homeostasis (physiological balance). Then, any excess of glucose is converted to fat necessarily, in adipocytes (fat cells) and liver [1].

Roles of insulin

Insulin is a hormone that promotes anabolism, both carbohydrates, but also proteins and lipids. This storage is a hormone. Insulin is the primary regulator of fat [2]. It is important to note that insulin metabolism leads to burning rather than to sugars that of fats.

Lipogenesis and lipolysis

Increasing insulin promotes lipogenesis, that is to say the formation of fatty tissue, thanks to the activation of lipoprotein lipase or LPL (enzyme enabling the formation of triglycerides from three fatty acids and glycerol). Conversely, the decrease in insulin promotes lipolysis and elimination of fat, thanks to the activation of homono-sensitive lipase or LHS (enzyme to "break" and triglycerides and free fatty acids so they can be burned). Lipogenesis and lipolysis are two processes always running hand in hand. The amount of insulin sets the trend.

High glycemic load and the role of insulin in weight gain: a vicious circle

Following an excessive intake of carbohydrates or foods with a high glycemic index, insulin acts to lower blood sugar. But what happens often is the appearance of a hypoglycemic reaction. Too low blood sugar and increases hunger and compulsions sweet. The new person eats and carbohydrates causes an increase in insulin and so on, each with a storage as fat. As seen above, as the high insulin metabolism is directed to the combustion of non-sugars and fat, a continuous vicious circle.

Why worry about insulin?

While insulin is not the only hormone involved in fat storage, but this is the main. In addition we can have a direct effect on its secretion by our food choices!

How secrete less insulin to lose weight?

Simply by reducing the total amount of ingested carbohydrates (see list of foods and their carb). This means avoid sugary products superfluous, who are also a source of "empty calories". But also reduce the consumption of carbohydrates, which is often excessive. Starchy foods should be eaten with the level of physical activity (a lot for a top athlete and very little for a sedentary).

Is also choosing foods based on their glycemic index (GI). IG is the potential of the feed hyperglycaemic. It replaces the old notion of carbohydrates and sugars, which is very often wrong. (See list of foods and their glycemic index database in English).

Fruits and vegetables should make the majority of carbohydrates in order to ensure that the diet is not too rich in carbohydrates and the glycemic index are not high.

conclusion

The first thing to do when we want to lose weight is to control blood glucose (to avoid peak) to reduce insulin secretion and thus promote the release of fat.