Effects of consuming compared with omitting breakfast on diet and physical activity in adolescent girls

Abstract

Epidemiological data has demonstrated that regular breakfast consumption is associated with favourable daily dietary intakes and reduced obesity risk in children and adolescents. There is also some evidence that regular breakfast consumers have higher levels of physical activity when compared with breakfast skippers. Therefore, it is of concern that breakfast skipping is particularly common among adolescent girls. However, the observational data on breakfast, diet and physical activity remains inconclusive and fails to infer causality. Therefore, the aim of this study was to experimentally examine the effects of consuming compared with omitting breakfast on diet and physical activity in adolescent girls. A sample of 33 girls (24 used in final analyses) aged 12-15 completed three, 3-day trials: habitual breakfast, no breakfast and high-energy breakfast. The participants’ dietary intakes were assessed using 3-day food diaries (and digital photography) and physical activity was measured with accelerometry. There was no main effect of trial on energy intake after breakfast (P=0.49), fruit and vegetable (P=0.21) and snack consumption (P=0.33). There was a significant main effect of breakfast condition on total daily energy intake (P=0.001) and on energy consumed from fat (P=0.001) and carbohydrate (P=0.001) when expressed as percentages of total daily energy intake. Daily energy intake was significantly higher in HEB compared with NB (P=0.001) and CON (P=0.002). Less energy from fat was consumed in HEB compared with CON (P=0.001) and NB (P=0.001), and more energy from carbohydrate was consumed in HEB compared with CON (P=0.001) and NB (P=0.001). There was no main effect of breakfast on time spent in sedentary (P=0.41), light (P=0.44), moderate (P=0.34) and vigorous (P=0.67) physical activity. Overweight and non-overweight adolescent girls did not compensate by consuming more energy or being less active for the remainder of the day when omitting compared with consuming breakfast consisting of ~475 kcal for three days.