Effect of breakfast omission and consumption on energy intake and physical activity in adolescent girls

Bowl of mixed berries and yogurt

The Nutrition Society Paper of the Month for September is from Public Health Nutrition and is entitled 'Effect of breakfast omission and consumption on energy intake and physical activity in adolescent girls: a randomised controlled trial'. 

Authors: Zakrzewski-Fruer JK, Plekhanova T, Mandila D, Lekatis Y, Tolfrey K.

‘Breakfast is the most important meal of the day’ is a well-known saying, but the literature on breakfast and health is dominated by cross-sectional data that cannot infer causality. The potential problem of skipping breakfast is of particular relevance to adolescent girls, as breakfast consumption frequency declines between childhood and adolescence and is lower in girls than boys. In large diverse samples of young people and adults, including adolescent girls, more frequent breakfast consumption is associated with lower risk of overweight and obesity. This association may be explained by higher energy intakes, lower energy expenditures, or a combination of the two in individuals who skip breakfast. The present study was the first to examine the causal nature of these links in adolescent girls by focusing on both sides of the energy balance equation. Specifically, we used an acute randomised, cross-over design, to compare the effect of three consecutive weekdays of breakfast omission with standardised breakfast consumption on free-living energy intake and physical activity (i.e. the most modifiable component of energy expenditure) in girls aged 11 to 15 years.

Our findings showed that post-breakfast energy intake was ~483 kJ/d higher during three days of breakfast omission compared with standardised breakfast consumption. However, as the standardised breakfast contained ~1962 kJ, total daily energy intake remained lower (by ~1479 kJ/d) during breakfast omission. This supports the small number of experimental studies showing that one day of breakfast omission does not increase subsequent energy intake to compensate for the energy deficit created by breakfast omission in children and in adolescents. Consistent with cross-sectional reports, total daily carbohydrate, fibre and protein intakes were lower during breakfast omission, whereas daily fat intake was not. These differences in daily macronutrient intakes were a direct effect of the breakfast meal, as post-breakfast intakes were not affected by breakfast manipulation. Although the small post-breakfast energy intake compensation suggests that higher physical activity energy expenditure may be more important in contributing to the lower adiposity in frequent breakfast consumers, breakfast manipulation did not affect time spent sedentary or in light or moderate-to-vigorous physical activity in our study. This is in contrast to some of the literature showing a causal link between breakfast consumption and physical activity energy expenditure in adults, highlighting that findings based on adult populations cannot necessarily be directly applied to adolescents. Due to the limited evidence base, further experimental research is required to determine the effects of extended periods of breakfast manipulation on energy intake and physical activity energy expenditure in young people, including children, adolescents, girls and boys. Ultimately, this will help to determine whether daily breakfast consumption should be promoted to improve dietary and physical activity behaviours that can reduce future disease risk in young people.

Photo with thanks to Eric Norris, Flickr, reproduced under a CC license.