What causes prediabetes?

What causes prediabetes?

• Some people are more at risk of getting prediabetes due to their genes. However, it is lifestyle factors that cause prediabetes to develop.
• Food choices are a key lifestyle risk factor. Excessive sugar, refined carbohydrate, and ultra-processed foods cause insulin resistance and fat to build up inside the abdomen (belly) and liver. This leads to a rise in blood glucose and a diagnosis of prediabetes.

No two people are the same. Some people seem to develop prediabetes whilst being quite careful about what they eat and their lifestyle. For others getting prediabetes comes as no surprise, and a diagnosis of prediabetes is the reality check they needed to get healthier. When I'm with a patient I think about their personal situation. A patient that has more belly fat and lots of family members with prediabetes is at higher risk.

For the human body to survive it must stay in balance. This balance is called homeostasis. The body must keep many things in balance, including blood glucose.

Prediabetes occurs when the body cannot keep the blood glucose level under control. This loss of control happens due to a combination of a person’s individual risk and their lifestyle. Some people are at greater risk of developing prediabetes because of their genes, but even so it is lifestyle that determines if insulin resistance and prediabetes develop.

When the body is in a healthy state it can keep control of the blood glucose level. After eating sugary or starchy foods blood glucose rises. This rise in glucose is sensed by the pancreas. The pancreas then releases the hormone insulin into the blood. Insulin travels in the blood and instructs parts of the body to take glucose out of the blood. This allows the blood glucose level to return to normal. Muscles and the liver are especially important for taking excess glucose out of the blood.

In prediabetes, the body has developed insulin resistance. The body is resisting the instruction from insulin to lower blood glucose. Insulin resistance can be thought of as body parts, such as the muscles and liver, being stuffed or overfull and having no room to take in more glucose. A consequence of insulin resistance is high blood glucose.

When an excessive amount of sugar, ultra-processed foods, and refined starchy carbohydrate foods are eaten the liver turns them into fat. If these foods are eaten frequently the liver, abdomen, muscles, and body’s fat stores become filled with fat. Once these body parts are filled with fat they stop responding to the signal from insulin – they are insulin resistant. It is important to note that it is the sugar and refined starchy carbohydrate foods that are the major contributor to the build of up fat.

It is the excess fat inside the abdomen that is more closely linked with insulin resistance and prediabetes rather than general body fat. As such, waist circumference (waistline) is a better indicator of insulin resistance than body weight. Body weight can be misleading as some people can build-up a lot fat inside the abdomen whilst having less overall body fat – this is an unhealthy state. Equally, some people can have more general body fat, and be heavier, whilst having less fat inside the abdomen – this is a healthier state. A person’s genes can influence where on the body fat gets stored.

• Mechanisms of Insulin Action and Insulin Resistance
• Visceral and ectopic fat, atherosclerosis, and cardiometabolic disease: a position statement