The impacts of lifestyle interventions in bariataric patients: a literature review

Background: The epidemic of obesity threatens the health of millions of people. When uncontrolled, obesity may progress to severe obesity (Body Mass Index ≥35 kg/m2). Bariatric surgery can induce substantial weight loss via gastric restriction and/or malabsorption and now is a viable treatment for severe obesity. The outcomes following surgery are variable. The long-term health of adults who have undergone bariatric surgery is influenced by how they reshape their lifestyles. Therefore, lifestyle modifications to diet, activity and related behaviors have great public health significance. This literature review summarizes findings from clinical studies on the effects of lifestyle interventions in bariatric surgery patients. Methods: A literature search was conducted in PubMed for English articles of clinical trials published between 1980 and 2015 that (1) enrolled adult (age ≥18 years) bariatric patients; (2) applied, either pre-operatively or post-operatively, a behavioral intervention aimed to improve patients’ diet, physical activity, or both that was delivered through counseling or educational sessions; (3) had a comparison group; (4) assessed any of the following outcomes: changes in weight, comorbidity status, cardiometabolic risk factors or targeted behaviors, such as physical activity. Results: The search using key terms yielded a total of 5944 articles, among which 15 met the eligibility criteria. Four studies assessing pre-operative interventions suggested the effectiveness of interventions on increasing pre-operative physical activity level. Eleven studies (3 lifestyle, 3 diet and 5 activity) examined post-operative interventions. The three studies with post-operative lifestyle interventions found the interventions effective at improving weight loss. None of the 3 diet studies observed difference in the weight loss between groups. The five studies with activity intervention observed effectiveness of intervention on increasing post-operative physical activity. The findings may not be valid due to their low quality. Conclusions: There is moderate evidence suggesting the effectiveness of pre-operative or post-operative lifestyle interventions on increasing activity level and of post-operative lifestyle interventions on improving weight loss. Due to heterogeneity in the design of the included studies, this review cannot conclude on the overall impacts of lifestyle interventions in bariatric patients. Future studies with high quality are needed to provide more evidence in this area