Researchers have found that young adults who skip breakfast are more likely to gain weight than those who do not. They also discovered that teens who miss the first meal of the day have a larger waistline, on average, compared to those who eat breakfast.
Researchers affiliated with the University of São Paulo's (USP) Medical School in Brazil and colleagues at institutions in Europe suspected that skipping breakfast can lead to an unbalanced diet and other unhealthy habits that increase the likelihood of weight gain.
They investigated this hypothesis and found that skipping breakfast – a common habit among teenagers – was directly correlated with an increased waist circumference and body mass index (BMI).
"We found that skipping breakfast is associated with adiposity markers in adolescents regardless of where they live and how much sleep they get, or whether they're male or female."
Elsie Costa de Oliveira Forkert, Epidemiologist and Member of the Youth/Child Cardiovascular Risk and Environmental Research Group
Forkert believes that the reason for this association is that children and adolescents who skip breakfast are more likely to replace a relatively healthy meal made from homemade products, whole grains and fruit with fast foods obtained from places on the way to or at school.
"This typically means consuming industrialized hypercaloric foods of low nutritional value, such as deep-fried snacks, pastries, sodas, and other sugary drinks, which are all directly associated with the development of obesity," she says.
The study analyzed data obtained from large cohort surveys held in Brazil and in European countries including Austria, Belgium, Germany, Greece, Italy, and Spain.
Data for the European study came from a survey called the "Healthy Lifestyle in Europe by Nutrition in Adolescence,” which included 3,528 adolescent males and females across ten major cities who were aged 12.5 to 17.5 years. Participants were stratified by age, gender, socioeconomic status, and religion.
The data for the Brazilian cohort came from a survey called the "Brazilian Cardiovascular Adolescent Health," which involved 991 teenagers, aged 14 to 18 years. Since childhood obesity can favor the early development of health problems such as type 2 diabetes and cardiovascular disease, these teenagers were assessed for cardiovascular risk factors and health-related behaviors.
Principal investigator Augusto Cesar Ferreira De Moraes (University of Sao Paulo) and colleagues analyzed the teenagers’ weight, height, and body mass index (BMI) as indicators of overall obesity and used waist circumference and waist-to-height ratio as measures of abdominal obesity.
Energy-balance-related behaviors were assessed using data from a questionnaire about levels of physical activity, with 60 plus minutes per day of moderate-to-vigorous exercise considered adequate and less than that considered as insufficient.
Sedentary behaviors were considered in terms of time spent on computers, video games or watching TV and participants were questioned about how long they slept for during the week and at weekends.
Attitudes towards food choices, healthy eating and lifestyle were assessed using a survey that included a question specifically about breakfast where the teenagers were asked to agree or disagree on a scale of 1 to 7 with the statement “I often skip breakfast.”
Skipping breakfast was associated with a larger waistline
As reported in the journalScientific Reports, the researchers found that of all the energy-balance related behaviors analyzed, the strongest correlation was between missing the first meal of the day and levels of obesity markers.
The results from both surveys showed that boys who skipped breakfast had increased waist circumferences, compared with boys who did eat breakfast.
"For boys who skipped breakfast, the average waist circumference was 2.61 cm larger in Europe and 2.13 cm larger in Brazil than those of boys who usually ate breakfast," says Forkert. The same applied to European girls, who had an average waist circumference that increased by 1.97 cm and an average waist-to-height ratio that was 0.02 higher.
On the other hand, when the researchers analyzed the association between sleep time and obesity markers, they found that the average BMI for boys who skipped breakfast was 1.29 kg/m² among European boys and 1.69 kg/m² higher among the Brazilian boys, even when they got sufficient sleep.
Among both European and Brazilian boys, skipping breakfast was the energy-balance related behavior that correlated most strongly with indicators of obesity such as increased BMI, waist circumference and waist-to-height ratio.
According to Forkert, this was also true of European girls: “Skipping breakfast correlated positively with total and abdominal obesity even when sleep time was adequate.”
In the Brazilian cohort, sedentary behaviors were more common among girls than among boys, while in the European cohort, such behaviors were more common among boys.
Among the European girls, sedentary behaviors that took up more than two hours per day were associated with an average increase in waist circumference of 1.20cm, even when sleep was considered sufficient
Among Brazilian boys, however, sleeping for less than eight hours per day had a protective effect against total obesity, which fell by an average of 0.93 kg/m².
Forkert says that teenagers with more sedentary behaviors who watch more TV, use a computer more or play more video games probably have an unbalanced diet and eat unhealthy foods, although such behaviors were not assessed in the current study.
"Sedentary behaviors associated with relatively high-calorie consumption lead directly to obesity,” she points out.
Forkert, E. C. O., et al. (2019). Skipping breakfast is associated with adiposity markers especially when sleep time is adequate in adolescents. Scientific Reports.https://www.nature.com/articles/s41598-019-42859-7