Impact of interventions to reduce overnutrition on healthcare costs related to obesity and type 2 diabetes: a systematic review

Context In recent decades, obesity and type 2 diabetes mellitus (T2DM) have both become global epidemics associated with substantial healthcare needs and costs. Objective The aim of this review was to critically assess nutritional interventions for their impact on healthcare costs to community-dwelling individuals regarding T2DM or obesity or both, specifically using CHEERS (Consolidated Health Economic Evaluation Reporting Standards) criteria to assess the economic components of the evidence. Data Sources Searches were executed in Embase, EconLit, AgEcon, PubMed, and Web of Science databases. Study Selection Studies were included if they had a nutritional perspective, reported an economic evaluation that included healthcare costs, and focused on obesity or T2DM or both. Studies were excluded if they examined clinical nutritional preparations, dietary supplements, industrially modified dietary components, micronutrient deficiencies, or undernutrition; if they did not report the isolated impact of nutrition in complex or lifestyle interventions; or if they were conducted in animals or attempted to transfer findings from animals to humans. Data Extraction A systematic review was performed according to PRISMA guidelines. Using predefined search terms, 21 studies evaluating food habit interventions or taxation of unhealthy foods and beverages were extracted and evaluated using CHEERS criteria. Results Overall, these studies showed that nutrition interventions and taxation approaches could lead to cost savings and improved health outcomes when compared with current practice. All of the included studies used external sources and economic modeling or risk estimations with population-attributable risks to calculate economic outcomes. Conclusions Most evidence supported taxation approaches. The effect of nutritional interventions has not been adequately assessed. Controlled studies to directly measure economic impacts are warranted.