Insulin is a hormone with a very strong influence on our metabolism. Its counterpart is glucagon. Both are produced and released by the beta cells of the pancreas.

Almost all the cells in our body carry insulin and glucagon receptors, to a greater or lesser extent. The muscle cells are densely packed with insulin receptors but have few glycogen receptors. The muscles, next to the liver, are the biggest glycogen storehouses of the body.

Insulin is essential to the survival of all mammals as it keeps the blood sugar level constant. Insulin is also the most important hormone for blood sugar regulation, for sugar in excess quantities is toxic to the cells. “Only” about two teaspoons (4g) of glucose circulate through our bloodstream

It is the insulin that makes us fat

Insulin determines our body weight. For when there is an excess of glucose (blood sugar), insulin ensures the glucose is transported away to the appropriate storage organs. This includes the musculature and the liver. Both are among the most important glycogen storekeepers of the body. About 400kcal can be stored in this way.

Glycogen can be described as stored carbohydrates.

It consists of interlinked sugar or glucose molecules.


100 calories from the biscuits I consume will make me much fatter than 100 calories from salmon.

But what happens to the rest? Well, any remaining excess ends up in the fat cells. It is the insulin that ensures any excess glucose is stored in the fat cells as triglycerides. This is the where the process of weight gain begins. The more carbohydrates putting pressure on the blood sugar level, the more insulin has to be released. .


But unfortunately the cells lose their responsiveness to insulin over time. The receptors become deaf as a result of constant stimulation. That applies to almost one in two of us. We are talking about insulin resistance here. First a pre-diabetic then a diabetic metabolic state is created, with all the well-known consequences. This metabolic state also prevents you from losing weight. When there is a persistently raised insulin level, no stored fat can be burnt off.

Insulin resistance


When the receptors of a cell are constantly overloaded with signals, at some point the cells stop responding. Their receptors become deaf, just like our ears when they are constantly subjected to the same sound.

For many of us, when, as a result of the sugars (carbohydrates) we consume, insulin has to be continually released in order to keep our blood sugar level constant, the cells stop responding to that insulin impulse. It means we have become resistant to insulin and now suffer from Type 2 diabetes. 

Glycaemic index

This figure tells you how much insulin is released by a particular food. The lower the index is, the less insulin is required to keep your blood sugar at a constant level. Blood sugar spikes trigger insulin release. The level in your blood drops rapidly, so you start to feel hungry again or crave more food.

Highly processed, ready-to-eat meals and carbohydrates like sugar and cereals need a great deal of insulin. Fat requires no insulin.


Melatonin – a hormone produced by the pituitary gland and fat cells


Melatonin is a fascinating molecule. In my opinion it receives too little attention and I have been guilty of overlooking it myself in the past. It is an ancient hormone and is found in almost all living organisms from the plant to the human body.

It has a central role to play in our metabolism. Energy distribution, body weight regulation and our internal clock – the circadian rhythms of the body – are greatly influenced by melatonin. What’s more, insulin cannot be effective in the absence of melatonin.


Melatonin helps fatty tissue change from white to brown. Light stops melatonin production. Disruption to the release of melatonin, which typically occurs when we age, do shift work or are affected by environmental light pollution, can lead to insulin resistance, sleep problems and metabolic disorders like obesity.