A systematic review of effects, potentialities, and limitations of nutritional interventions aimed at managing obesity in primary and secondary health care

Objectives: Obesity has been identified as an important risk factor for cardiovascular disease and other chronic diseases. However, dietary treatment of obesity is far from being a closed issue. Therefore, it is critical to identify the most appropriate obesity management approaches. The aim of this review was to summarize the effects, potentialities, and limitations of nutritional interventions aimed at managing obesity in primary and secondary health care settings, highlighting the most effective strategies and theories. Methods: This systematic review of randomized controlled trials evaluated nutritional interventions aimed at achieving weight loss in primary and secondary health care patients. All screening and extraction processes were conducted according to PRISMA. Results: From an initial 7816 studies that were identified, 28 met the criteria and were included in the review. Most studies were conducted in a developed country in primary care, with a higher proportion of women. Most of the nutrition interventions maintained continuous contacts during follow-up, and telephone calls were the most commonly used technology. A physical activity component was included in most studies, and the most common dietary approaches used were energy restrictions, changes in macronutrient distribution, and diet self-monitoring. Regarding theories, interventions mainly incorporated Social Cognitive Theory and Motivational Interviewing. Most trials presented significant and moderate weight loss (similar to 5%), in which the key contributors were behavioral theories, the dietary approach of calorie restriction, and interventions delivered by dietitians and psychologists. Conclusions: Most trials presented better weight loss results with the association of calorie restrictions and theory-based interventions delivered by dietitians or psychologists. We identified the need to develop interventions in other contexts, such as low- and middle-income countries; further trials comparing a theory-versus not-theory-driven intervention; group-based versus individually based intervention; and intervention using or not using technology. (C) 2020 Elsevier Inc. All rights reserved.