PHYSICAL ACTIVITY AND SATIETY IN PEOPLE WITH TYPE 2 DIABETES

Physical activity guidelines for people with prediabetes (impaired fasting glucose or impaired glucose tolerance) and type 2 diabetes are mainly based on research on the effects of exercise on health outcomes, such as glycemic control (e.g., HbA1c), insulin sensitivity, blood lipids (e.g., cholesterol and triglycerides), and blood pressure. The impacts of exercise on appetite (e.g., hunger, satiety, fullness, etc…), energy balance, and consequently body weight are less studied, although it has been acknowledged for over 60 years that a relationships exists between these factors.

In people with normal glucose tolerance, in the short term, exercise usually results in a relative energy (calorie/kilojoule) deficit due to the additional energy expended during physical activity. High-intensity exercise in particular has been shown to rapidly decrease feelings of hunger, and the phenomenon is known as exercise-induced anorexia. However, over longer periods of time, such an exercise-induced energy deficit is often diminished due to a compensatory increase in energy intake, as well as to a compensatory reduction in other areas of daily energy expenditure, e.g., non-exercise activity thermogenesis. These compensatory responses vary significantly between people and seem to become more pronounced with higher amounts of exercise.

There are indications that appetite regulation is altered in people with prediabetes or type 2 diabetes compared to individuals with normal glucose tolerance due to a dysregulation of central and peripheral sensitivity to appetite-regulating signals, including central insulin resistance, and decreased sensitivity to certain appetite hormones.

A recent systematic review of clinical trials investigated the effect of physical activity or a physical training interventions on hunger, satiety, fullness, appetite and hunger hormones in people with impaired glucose metabolism. Trials published before August 2023 were eligible for inclusion. After searching PubMed, Web of Science and the Cochrane Central Register of Controlled Trials, a final total of 7 eligible studies were identified, which included 211 adults, of which 28 had pre-diabetes and 183 had type 2 diabetes.

Results of the studies can be summarised as:

• the perception of fullness in patients with type 2 diabetes is increased immediately after exercise
• In the long term, aerobic endurance exercise performed for at least 150 min per week (e.g., brisk walking, 3–5 times per week) or in combination with resistance exercise (20 min/day, 2–3 times per week) is best for decreasing hunger and increasing satiety
• There was no clear association between hunger hormones (GLP-1, etc…) and appetite ratings

The authors concluded that there is evidence for an appetite-reducing rather than an appetite-increasing effect of chronic exercise in people with prediabetes or type 2 diabetes, but as is commonly the case, more research is needed due to the relatively small number of studies conducted to date.

Read more: