Achieving a healthy weight might involve more than just selecting nutritious foods; the timing of meals could also play a key role. According to a study in the International Journal of Behavioral Nutrition and Physical Activity, two practices are associated with a reduced body mass index (BMI) in the long term: lengthening the time without eating overnight and having breakfast soon after waking. The investigation was conducted by the Barcelona Institute for Global Health (ISGlobal), an organization backed by the ‘la Caixa’ Foundation.
The results stem from information gathered from over 7,000 people aged 40 to 65, participants in the GCAT | Genomes for Life project managed by the Germans Trias i Pujol Research Institute (IGTP). In 2018, these individuals submitted data on their height, weight, eating schedules, daily routines, and economic status via surveys.
By 2023, more than 3,000 of them participated in follow-up evaluations. Scientists noted new metrics and gathered additional questionnaire responses, enabling them to monitor developments and spot trends across the years.
Benefits of Early Meals and Prolonged Fasting for BMI
‘Our findings align with other recent research, indicating that a longer overnight fast might support weight management when paired with an early evening meal and morning meal. We believe this approach synchronizes better with the body’s natural rhythms, improving energy expenditure and hunger control, which could aid in sustaining a healthy weight. Still, it’s premature for firm conclusions, and guidelines should await stronger proof,’ said Luciana Pons-Muzzo, who was an ISGlobal researcher during the project and now works at IESE Business School.
Variations by Gender and Daily Habits
Analysis by gender revealed distinct patterns. Women tended to have lower BMIs, adhered more to the Mediterranean diet, and consumed less alcohol. However, they often reported worse mental well-being and greater involvement in home or family duties.
Employing cluster analysis, the team categorized participants with comparable traits. A minor subset of men was distinctive: they usually started eating after 2 p.m. and fasted for around 17 hours. Relative to others, this group smoked and drank more, exercised less, deviated from the Mediterranean diet, had lower education, and faced higher unemployment. No equivalent group emerged among women.
Insights on Intermittent Fasting and Omitting Breakfast
‘Various methods exist for intermittent fasting, and our work examines one form: fasting through the night. In a specific group of men who fast intermittently by forgoing breakfast, we saw no impact on weight. Other trials with obese individuals have found this method no better than cutting calories for long-term weight loss,’ noted Camille Lassale, an ISGlobal scientist and the study’s senior co-author.
Chrononutrition and Internal Body Rhythms
‘This work contributes to the growing area of chrononutrition, which explores not just dietary content but also eating times and frequency,’ stated Anna Palomar-Cros, an ISGlobal researcher at the time and now at IDIAP Jordi Gol. ‘It draws on the understanding that irregular eating can disrupt the circadian system, which governs daily cycles and related bodily functions,’ she explained.
Connections to Wider Health Advantages from Timely Eating
The current study expands on prior ISGlobal chrononutrition research. Earlier work linked earlier dinners and breakfasts to decreased risks of heart disease and type 2 diabetes, underscoring the importance of meal scheduling for overall health.
