Can diet and exercise prevent type 2 diabetes?

This study investigated the effects of diet and physical activity in preventing or delaying type 2 diabetes (T2D), and its complications, in people at high risk of developing T2D. It was determined that diet and/or physical activity reduces or delays the development of T2D in these people.

The number of people with T2D is expected to increase in coming years. Changes in lifestyle (such as diet and exercise) are an important treatment for T2D. It is recommended that people with prediabetes make similar lifestyle changes. People with prediabetes have blood glucose levels higher than considered normal, but lower than those in people with T2D. They are at high risk for developing T2D. Whether and how diet and physical activity can prevent or delay T2D in people with prediabetes is uncertain.

This study examined data from 12 different studies. 5238 adults with prediabetes participated in these studies. They were randomly divided into physical activity and/or diet groups, and control groups who did not diet or increase their physical activity. The studies lasted between 2 and 6 years.

11 studies compared diet and physical activity to control groups. Those in the diet and physical activity group were 43% less likely to develop T2D than the control group. Just 14.8% of participants in the diet and physical activity group developed T2D, compared to 25.7% in the control groups. 12 out of 2049 participants in the diet and physical activity group died during the study, compared to 10 out of 2050 in the control group. Serious side effects and death due to cardiovascular causes were rare. No significant difference in health-related quality of life was found between the two groups. Health-related quality of life is a measure of a person’s satisfaction with their life and health.

A smaller number of studies examined the effects diet or physical activity only. In one study 43.8% of people in the diet-only group developed T2D, compared to 41.1% of the physical activity-only group, and 67.7% of the control group. In another study, 11.9% of participants in the physical-activity only group developed T2D, compared with 18% of the control group. Serious complications and death were rare.

The study concluded that diet and physical activity delays or reduces the progression to T2D in people with prediabetes. There was not enough information to determine the effects on mortality, heart disease, and other complications of diabetes.

The different studies used different definitions of prediabetes and T2D, which may have made comparisons difficult. The intensity of diet and physical activity varied in different studies. This may have affected the results.

Discuss the effects of lifestyle changes, like diet and physical activity, with your physician. It is always important to check with your physician before starting a new exercise program or increasing the intensity of a previous program.