The Association Between Consumption of Foods/Food Groups and the Risk of Overweight/Obesity and Metabolically Unhealthy Obesity in Children and Adolescents: A Systematic Review and Meta-Analysis.

Existing studies have suggested an association between consumption of foods/food groups and the risk of childhood overweight/obesity (OV/OB) and metabolic unhealthy obesity (MUO). However, they are heterogeneous in terms of design, samples and outcomes, and most do not provide evidence of long-term longitudinal associations given their cross-sectional nature. The aim of the present work was to systematically review longitudinal evidence of the association between foods/food groups and the risk of OV/OB and MUO in children and adolescents aged 2-19 years. Two databases (Scopus and PubMed) were searched for original research conducted in Western countries. Prospective epidemiological studies (PES) and randomized controlled trials (RCTs) with exposures/interventions related to the consumption of foods/food groups, OV/OB- or MUO-related outcomes and ≥1-year follow-up were considered eligible. A narrative evidence synthesis, complemented by random-effects meta-analyses where feasible, was performed. The review protocol was registered in PROSPERO (ID: CRD42024496148). The narrative synthesis of 23 longitudinal studies revealed a detrimental effect of sugar-sweetened beverages (SSBs) (n = 8/10 PESs and 1/2 RCTs) and ultra-processed foods (UPFs) (n = 2/3 PESs), and a beneficial effect of full/higher-fat dairy products (n = 2/3 PESs) on OV/OB-related outcomes, although certainty in evidence was (very) low. Evidence was inconclusive for artificially sweetened beverages, fruits and vegetables (primarily 100% fruit juices), milk and total dairy products. Random-effects meta-analysis of PESs focusing on SSBs revealed a positive association with follow-up body mass index (n = 3, pooled beta: 0.16 kg/m2, 95%CI: 0.09, 0.23) but a non-significant association with change in BMI (n = 3, pooled beta: 0.07 kg/m2, 95%CI: -0.05, 0.19). Only 1 PES reported on MUO-related outcomes and revealed a potential beneficial link between higher-fat milk intake and selected cardiometabolic indices. In conclusion, consumption of SSBs is positively associated with indicators of childhood OV/OB risk. A detrimental effect of UPFs and a beneficial effect of higher-fat dairy products on childhood adiposity outcomes were also observed, but the available evidence remains limited and insufficient to draw robust conclusions. Data for other foods/food groups and OV/OB, as well as for their link with childhood MUO, remain scarce and inconclusive.