The effectiveness of physical activity interventions for the treatment of overweight and obesity and type 2 diabetes.

This review summarises current evidence relating to the effectiveness of physical activity (PA) interventions for treating overweight and obesity and type 2 diabetes. Interventions to increase PA for the treatment of overweight and obesity in both children and adults have primarily consisted of health education and behaviour modification strategies in clinical settings or with selected families or individuals. Although evidence is limited, strategies to reduce sedentary behaviours appear to have potential for reducing obesity among children and adolescents. Among adults, strategies that combine diet and PA are more effective than PA strategies alone. Combined lifestyle strategies are most successful for maintained weight loss, although most programs are unsuccessful in producing long-term changes. There is little evidence about compliance to prescribed behaviour changes or the factors that promote or hinder compliance to lifestyle changes. Limited evidence suggests that continued professional contact and self-help groups can help sustain weight loss. Most of the interventions for the treatment of type 2 diabetes have been conducted in clinical settings and have typically required the use of extensive resources. Evidence suggests that interventions can lead to small but clinically meaningful improvements in glycaemic control, even in the absence of weight loss. A recent study demonstrated that a multifactorial intervention (diet, PA and pharmaceutical) can reduce the risk of diabetes complications in individuals with type 2 diabetes. Nevertheless, there is little evidence about the effectiveness of community-based interventions in producing long-term changes in glycaemic control and reduced mortality in people with type 2 diabetes.