Effect of breakfast eating versus breakfast skipping on obesity related anthropometry: a systematic review

Background Breakfast consumption is frequently recommended for weight loss and the prevention of obesity. Although breakfast eating has been repeatedly associated with lower BMIs through numerous observational studies and meta‐analyses of observational studies, the causal effects of eating versus skipping breakfast on obesity has not been systematically reviewed. Objective To synthesize available evidence on the effects of eating versus skipping breakfast on anthropometric measures related to weight in randomized controlled trials. Methods Scopus, PsycInfo, CINAHL, Alt‐HealthWatch, and Proquest Global Thesis and Dissertation databases were searched for randomized controlled trials in humans that investigated the effects of breakfast consumption or skipping on weight‐related outcomes. Inclusion criteria were: studies with 72 hours or longer of intervention; reported changes in weight‐related outcomes measured objectively; participants with normal weight or greater; participants without diseases expected to influence weight; and the effects of breakfast eating versus breakfast skipping could be isolated from other treatment components. Titles and abstracts were double coded. Results The search resulted in 4,047 results across databases; 3,255 after duplicates removed; and 3,182 after animal studies were removed using an automated approach. Titles and abstracts from 47 entries were reevaluated for inclusion, with 19 evaluated at the full text level. Two additional articles were identified from alternative sources. Only 6 articles met all criteria, with another 6 papers (possibly only 3 unique studies) seeming to meet all criteria except for reporting of weight. In the 6 papers that met all the criteria, 4 studies were conducted in the US, 2 in the UK; 5 studies in adults, 1 in adolescents (age 18+); study length ranged from 2–16 weeks; 4 parallel arm RCTs, 2 cross‐over RCTs; 3 provided meals and 3 gave recommendations/meal plans; weight‐related outcomes included fat mass, fat mass index, percent fat mass, BMI, fat free mass, waist circumference, waist:hip ratio, and body mass; and the n randomized ranged from 5 to 56 per treatment arm. Of 38 comparisons among breakfast vs skipping on weight‐related outcomes, 2 were significant in favor of a breakfast, and two were significant in favor of skipping. The rest were non‐significant. Conclusions This systematic review does not support the general contention that eating versus skipping breakfast is beneficial for weight‐related outcomes. This does not preclude the possibility that certain types of breakfasts or certain populations may respond positively or negatively to eating vs skipping, or that breakfast may have other health beneficial or detrimental effects. Quantitative synthesis of these results is forthcoming. This systematic review and meta‐analysis was registered at http://www.crd.york.ac.uk/PROSPERO/as CRD42016033290.