Adult macronutrient intake and physical capability in the MRC National Survey of Health and Development

Background: poor physical capability is associated with higher subsequent risk of disability and mortality in older people. Energy and macronutrient intakes may play a role in the maintenance of physical capability. This analysis aimed to examine the role of intakes of energy and the macronutrients, protein, carbohydrate and fat in early and mid-adulthood on objective measures of physical capability in later adulthood in the MRC National Survey of Health and Development (1946 British birth cohort). Methods: adult diet assessed by a 5-day diary at 36 years (1982) and 43 years (1989). Physical capability was assessed at 53 years. Objective measures were height, weight and three measures of physical capability: grip strength, standing balance time and chair rises. Results: using multiple linear regression analysis, modest positive associations were found between energy intake at 36 and 43 years and grip strength at 53 years. Results for macronutrients were mixed although there was some indication of relationships of protein intake with grip strength and standing balance time. Conclusions: higher energy intake in midlife may play a role in the prevention of muscle weakness in later life. Higher protein intakes may also be related to physical capability but further research is needed.