Randomised controlled trials (RCTs) that compared interventions primarily aimed at weight loss with placebo, no intervention or another active intervention were eligible if they enrolled patients with a mean age at least 60 years and a body mass index (BMI) of at least 30kg/m2 and had a minimum follow-up period of one year.
Outcomes of interest were weight, BMI, total cholesterol, high-density cholesterol (HDL), low-density cholesterol (LDL), triglycerides, fasting glucose, glycosylated haemoglobin (HbA1c), blood pressure, deaths, hospitalisations, morbidity, quality of life, measures of physical function and exercise capacity, and drop-outs.
All of the studies except one evaluated dietary advice. Other intervention components included exercise or advice about physical activity, behavioural counselling and various activities. Control interventions varied and included usual care, clinic appointments, talks, discussions and less intensive interventions. All of the studies except one were set in USA. Studies included single and multicentre studies. Interventions were conducted in primary care, the community and secondary care. Mean age ranged from 58 to 71 years. All patients lived in the community. A few studies targeted patients with BMI at least 35kg/m2. Most studies were in patients with specific medical conditions; these included diabetes mellitus, coronary artery disease and osteoarthritis.
The authors did not state how papers were selected for the review.