"Larks" and "owls" age differently

This is the conclusion reached by researchers from the University of Barcelona after analysing data on the relationship between biological rhythms and lifestyle, muscle mass and metabolic health.

The results are presented in a scientific review paper published in the journal Nutrients. The study involved experts from the University of Barcelona, the University Hospital of Belvidge, the Biomedical Research Institute of Belvidge (IDIBELL) and the Spanish Network for Diabetes and Metabolic Diseases (CIBERDEM). The project was led by Professor Pablo M. Garcia-Roves.

Biological clock and muscle health

The authors note that chronotype - a person's innate biological tendency to be more active during certain hours of the day - plays an important role in the maintenance of muscle mass, quality and strength, as well as influencing metabolic health. This may explain why the same recommendations for diet, physical activity and daily routines have different effects in different people.

The researchers analysed existing scientific evidence on the interaction between biological clocks and lifestyle habits - diet, physical activity and sleep - particularly in the context of obesity and ageing.

"Chronotype determines how we distribute activity throughout the day and indirectly influences key factors of muscle health - resting, exercise and meal timing," explains IDIBELL researcher Roberto Barrientos-Salinas.

When social schedules go against biology

According to the review, people with an evening chronotype are more likely to eat late, have less stable sleep patterns and are less likely to stick to regular physical activity. This mismatch between internal biological clocks and social schedules can lead to a less healthy lifestyle and negatively affect muscle quality and metabolism.

However, the scientists emphasise: chronotype is not a matter of willpower or habits, but a biologically determined trait linked to genetics and physiology.

Muscle is a key factor in healthy ageing

Special attention is paid to the role of muscle tissue as an essential organ for health. Muscle is essential not only for movement and strength, but also for normal metabolism and maintaining functional independence in old age.

Researchers warn of the risk of sarcopenic obesity, a condition in which excess fat mass is combined with muscle loss and reduced muscle function. This combination substantially increases the risk of deteriorating quality of life as we age.

Towards personalised recommendations

The authors of the review call for a move towards more personalised prevention and treatment strategies that take into account a person's chronotype. This involves matching meal timing (chrono-nutrition), exercise and sleep to individual biological rhythms.

"Taking chronotype into account can help make health recommendations more accurate and sustainable in the long term - especially in weight loss programmes, preventing muscle loss and supporting healthy ageing," notes Professor Nuria Villarraza, Head of Endocrinology and Nutrition at the Belvidge Clinic.

Significance for medicine and public health

Although the work is observational in nature, the findings may have important implications for clinical practice and public health. An individualised approach to activity and rest regimes could form the basis of more effective prevention programmes, especially in the context of irregular work schedules and ageing populations.

"The main goal is for people to stay active and avoid sedentary lifestyles. But understanding individual biological characteristics allows us to develop more precise interventions that actually improve health and functional capacity," Professor Garcia-Roves concluded.