Diet & Nutrition: 5 Ways to Prevent Type-2 Diabetes

By Richard Béliveau, Ph.D.,
and Denis Gingras, Ph.D.

Given the serious consequences emanating from insulin resistance and Type-2 diabetes, preventing this disease is certainly our best weapon in reducing the damage caused by a surplus of blood sugar. Luckily for us, the preventive potential is extraordinary: Adopting a healthy lifestyle can prevent up to 90% of Type-2 diabetes cases! To see how we can reduce the risk of diabetes, let us review some lifestyle factors.

Controlling body weight – Given that excess weight and obesity are instrumental in the development of Type-2 diabetes, maintaining a normal body weight is an essential aspect of any preventive approach. The most spectacular illustration of how weight loss can influence the risk of diabetes is undoubtedly the effect of bariatric surgery (reducing stomach size) on morbidly obese people. Radically reducing the size of the stomach rapidly decreases obesity and almost completely eliminates Type-2 diabetes!

However, it is neither necessary nor desirable to undergo this type of surgery to reap the benefits of weight loss: Losing just 5 kg, even over several years, can reduce the risk of diabetes by 50%! At a time when overweight has become the norm rather than the exception, Type-2 diabetes undoubtedly illustrates the dangers of excess weight and the need to be as slim as possible in order to prevent this disease.

The second main form of sugar is starches. These are created by combining a number of sugar molecules. Starch is found in cereals, potatoes, and certain vegetables and legumes. Generally, the sugar present in foods in starch form is digested more slowly than simple sugars. Conversely, all starches are not digested at the same rate: For example, potato starch has a structure that breaks down into sugar very quickly while legume starches are much more resistant.

The third main form is dietary plant fibres, found only in plant products such as vegetables, fruits, and whole grains. These fibres are so complex that our stomach cannot digest them and only the bacteria present in our intestines can extract a small amount of their sugar content.

The main difference between the various types of carbohydrates is how fast they are absorbed by the intestine and transported into the bloodstream. In the case of simple sugars, their rapid assimilation forces the pancreas to react by secreting a large amount of insulin. Conversely, in the case of dietary plant fibres or complex starches, the intestine breaks down these sugars much more slowly, causing sugar to appear gradually in the blood and produce less insulin. To distinguish the effects of carbohydrates on blood glucose, we use the concepts of glycemic index and glycemic load.

Ingesting a food with a high glycemic load, such as corn flakes, rapidly increases the blood glucose level, which is accompanied by a massive secretion of insulin striving to absorb all the sugar. However, it may happen that the amount of insulin produced by the pancreas in response to this sugar level is too great, which can result in excessive glucose absorption, and paradoxically, a hypoglycemic state a few hours after eating a meal. This is not a desirable outcome as the lack of glucose in the blood greatly stimulates the centres involved in appetite control, causing a craving for more food to raise the glucose level. If repeated excessively, these fluctuations will not only wear out the pancreas but also promote obesity. Actually, insulin helps convert sugars into fats, as well as store them in the adipose tissues.

Conversely, consuming foods containing complex carbohydrates (with a low glycemic load, such as whole grain products and legumes) produces a much smaller amount of glucose and insulin in the blood. Under these conditions, the glycemia is stabilized over a longer period, without hypoglycemic episodes. By avoiding blood glucose fluctuations, this type of carbohydrate reduces insulin production and prevents overloading of the pancreas. In addition to being important for diabetics or pre-diabetics, who must maintain a stable glycemic level, consuming complex carbohydrates with a low glycemic load is a dietary change that can have a big impact on diabetes prevention in general.