Studies conducted in Europe that investigated breakfast consumption of children or adolescents (under 18 years) and reported on at least one outcome of body weight, body weight changes and body mass index (BMI) were eligible for inclusion.
The included studies were cross-sectional or cohort studies conducted in Croatia, Czech republic, Denmark, Finland, Greece, the Netherlands, Norway, Portugal, Spain, Sweden and UK. Children and adolescents ranged in age from between seven and 21 years. Breakfast was defined in only a few studies. Several definitions of breakfast skipping were used (included breakfast frequency) to define the number of days in which breakfast was eaten. Definitions of being overweight and/or obese varied across studies.
The authors did not state how many reviewers performed study selection.