Teenage girls who missed breakfast increased their post-breakfast EI, but their overall daily calorie consumption was lower than those who ate breakfast, discovered the research team, a collaboration between the University of Bedfordshire and Loughborough University.
The study also found that consuming breakfast made no difference to the amount of physical activity undertaken by the girls.
“In this sample of adolescent girls, breakfast omission increased post-breakfast free-living EI, but total daily EI was greater when a standardised breakfast was consumed. We found no evidence that breakfast consumption induces compensatory changes in physical activity,” wrote first author Dr. Julia Zakrzewski-Fruer, Lecturer in Health, Nutrition and Exercise at the University of Bedfordshire.
Some previous observational studies have suggested that skipping breakfast may be associated with overweight and obesity. Assumptions of a causal effect have led to calls for breakfast interventions as a means of curbing obesity.
These study findings are significant, because they provide interventional trial evidence to suggest the previous assumptions are unfounded.
The randomised crossover trial recruited 49 girls aged 11-15 years from schools in two locations in England.
“Participants completed two, 3-day conditions in a counter-balanced order: no breakfast (NB) and standardised breakfast (SB). The conditions were conducted across the same three weekdays (i.e., Tuesday, Wednesday and Thursday) with either a 4 or an 11 day washout between conditions,” explained the researchers.
The girls were asked to fast from 21.00 the previous evening. On arrival at school, the NB group received water and were told to avoid snacking until 10.30, and to report that they had complied with this instruction.
The SB group consumed their meal between 8.15 and 8.45. The SB consisted of 56 grams of wheat biscuits (Weetabix), 188 millilitres (ml) of semi-skimmed milk and 375 ml of orange juice. The energy content of the SB was around 470 kilocalories (kcal). This intake was considerably higher than the girls’ habitual breakfast EI of 183 kcal.
Girls who did not eat breakfast consumed around 115 kcal of snacks between 10.30 and 13.00 to compensate – around a quarter of the energy value of the SB.
Total daily EI was around 353 kcal higher in the SB group, which is almost exactly the calorific difference between the SB breakfast and the post-breakfast snacks consumed by the NB group.
This further suggests that skipping breakfast actually reduces overall energy consumption, rather than increasing it, contrary to previous observational study findings.
As this intervention looked at 3-day periods, the researchers suggested that further work should examine the effect of regularly missing breakfast over longer durations.
Recent research has also suggested that increasing protein content of breakfasts may promote satiety. It may therefore be interesting to conduct a similar study where the SB consists of a protein-rich meal.
Source: British Journal of Nutrition
Volume 118, issue 5, pp 392-400. DOI: 10.1017/S0007114517002148
“Effect of breakfast omission and consumption on energy intake and physical activity in adolescent girls: a randomised controlled trial”
Authors: Julia K. Zakrzewski-Fruer, T. Plekhanova, D. Mandila, Y. Lekatis and K. Tolfrey