The study, which followed nearly 400 adults over a three-year period, found that individuals who adhered to the recommended caloric range for breakfast exhibited a lower body mass index (BMI) compared to those who either consumed too few or too many calories.
Published in The Journal of Nutrition, Health and Aging, the research focused on 383 obese adults aged 55 to 75 in Barcelona, all of whom had metabolic syndrome—a condition characterized by health issues such as high blood pressure and elevated cholesterol levels, which increase the risk of heart disease and diabetes. Participants followed a Mediterranean diet rich in vegetables and whole grains to facilitate weight loss.
Throughout the study, researchers tracked the participants' breakfast calorie consumption at the outset, after two years, and at the conclusion of the study. Findings indicated that those who consumed inadequate or excessive calories at breakfast had a BMI that was 2 to 3.5 percent higher than those who consumed the appropriate amount. Additionally, waist circumference, a measure of abdominal fat, was found to be 2 to 4 percent larger in individuals with improper breakfast intake.
Blood tests revealed that individuals who either under-consumed or over-consumed calories at breakfast had elevated blood fat levels, a known risk factor for heart disease. The BMI scale categorizes a healthy range as 18.5 to 25, overweight as 25 to 29, and obesity as 30 or higher, which significantly increases health risks.
The research also evaluated the nutritional quality of breakfast meals. Participants who consumed breakfasts high in unhealthy fats, salt, and sugar faced increased health risks, independent of their calorie intake. While it is expected that individuals with higher calorie consumption would have elevated BMI and waist measurements, it remains unclear why those with lower calorie intake also exhibited similar adverse effects. Researchers propose that individuals who eat breakfast may experience greater satiety throughout the day, which could lead to less frequent snacking and a reduction in total calorie consumption.
Professor Álvaro Hernáez, one of the authors from Ramon Llull University, highlighted the importance of breakfast, noting that both quality and quantity are significant. He pointed out that a balanced intake—avoiding extremes of too much or too little—combined with proper nutrition, contributes to improved heart health.
The authors acknowledge certain limitations within the study. As it is observational in nature, it cannot conclusively establish that breakfast calorie intake directly influences health outcomes, despite the data indicating a potential link. They also took into account various other factors that could affect the results.