Preventing weight gain by lifestyle intervention in a general practice population: the Groningen Overweight And Lifestyle-(GOAL)-randomized controlled trail

According to (inter)national guidelines persistent lifestyle changes are necessary for preventing and managing obesity. Studies on lifestyle interventions have shown a decrease in the risk of type 2 diabetes mellitus and hypertension. Positive changes in lifestyle will improve health status even without losing weight. There’s no consensus on the most (cost)-effectiveness way for lifestyle-interventions but factors like attention for nutritional and physical activity aspects, continuity and intensity are important.

In this study we, therefore concentrate on preventing weight gain in a large study group with a body mass index 25 to 40 kg/m2 with either hypertension and/or dislipidemia (n=457). This early focus to prevent (progression of) future comorbidities might have larger long-term success than when aimed at weight loss. In the Netherlands, GPs are often responsible the treatment of risk factors like hypertension and dyslipidemia and they also give lifestyle advices. Lack of time and knowledge to achieve behavioral changes and insufficient continuity of care impede this approach by GPs To avoid these barriers specially trained nurse practitioners may give lifestyle advice (using a standardized computerized software program) instead of GPs.

This study primary investigates the effect (after 1 and 3 year follow-up) of lifestyle advice by NPs on bodyweight, waist circumference, physical activity and food intake in comparison to usual care of the GP. Secondary this effect is investigated on blood parameters like fasting glucose and cholesterol, blood pressure and quality of life.

We expect that lifestyle counseling by nurse practitioners will be more effective (also on the long term) on body weight and changes in lifestyle than usual care by the general practitioner.

At baseline, 1 year follow-up and 3 year follow-up.

The intervention group will visit the nurse practitioner for lifestyle counseling according to a standardized computerized software program. During the first year the lifestyle intervention consists of 4 individual visits and 1 feedback moment by phone.

The second and the third year consists of 2 feedback moments by phone and 1 individual visit each year.

The participants in de control group received usual care according to national guidelines from their own GP.