Bariatric treatments for adult obesity - Institute of Health Economics

greater reduction of weight and BMI. Increasing the intensity of exercise resulted in increased weightloss if participants were not on a dietary therapy; high-intensity exercisers lost 1.5 kilograms morethan did low-intensity exercisers. However, if exercisers were also on a dietary therapy, high exerciseintensity did not increase weight loss compared to low exercise intensity.A subgroup analysis by gender did not show any relevant changes in pooled estimates. Analysis byage demonstrated that, as compared to the dietary-therapy-alone group, the pooled effect for weightreduction in the exercise and diet group was 1.6 kilograms more for participants with a mean age of45 years or less, and 1.0 kilograms more for participants with a mean age greater than 45 years. Nosubgroup analysis was conducted based on BMI cutoffs.The other review 58 of adults with a BMI greater than 25 kg/m 2 showed that the combination ofdietary therapy and physical exercise resulted in a mean weight loss approximately 20% greater thanthat experienced by the dietary-therapy-alone group, both immediately after the intervention periodand after 1 year follow-up; these difference were not statistically significant. In both groups, themagnitude of weight reduction immediately after intervention and after 1 year of follow-up iscompatible with clinically significant benefits; that is, with a reduction in obesity-related risk factors.However, adults in both groups regained 50% of their lost weight after 1 year. Adding exercise todiet did not produce better long-term maintenance of the weight losses.Behavioural therapyDescription of the included studiesThe only systematic review 15 in this category assessed 36 RCTs for the effects of variouspsychological interventions on weight loss in 3495 overweight and obese adults (Table T.F.1-2). Theincluded studies were heterogeneous in terms of participants, interventions, outcome measures, andsettings. Most studies had a follow-up period of less than 12 months. Studies with an attrition ratehigher than 15% were excluded in this review.Methodological quality and limitationsAll 36 RCTs suffered from some methodological weakness. Only two studies reported the methodof randomization. Blinding of investigators to outcomes was not clear or not done in all but onestudy. Sample sizes in many studies are small. Intention-to-treat analysis was performed in only threestudies. Only one study met all the quality criteria.EffectsMain findings from this systematic review are summarized in Table T.7.Bariatric treatments for adult obesity 81