Greater male variability in daily energy expenditure develops through puberty.

There is considerably greater variation in metabolic rates between men than between women, in terms of basal, activity and total (daily) energy expenditure (EE). One possible explanation is that EE is associated with male sexual characteristics (which are known to vary more than other traits) such as musculature and athletic capacity. Such traits might be predicted to be most prominent during periods of adolescence and young adulthood, when sexual behaviour develops and peaks. We tested this hypothesis on a large dataset by comparing the amount of male variation and female variation in total EE, activity EE and basal EE, at different life stages, along with several morphological traits: height, fat free mass and fat mass. Total EE, and to some degree also activity EE, exhibit considerable greater male variation (GMV) in young adults, and then a decreasing GMV in progressively older individuals. Arguably, basal EE, and also morphometrics, do not exhibit this pattern. These findings suggest that single male sexual characteristics may not exhibit peak GMV in young adulthood, however total and perhaps also activity EE, associated with many morphological and physiological traits combined, do exhibit GMV most prominently during the reproductive life stages.

A new doubly labelled water anthropometry-based equation for prediction of total daily energy expenditure in older people from low- and middle-income countries.

BACKGROUND: For community-living older people, the ability to estimate total daily energy expenditure (TDEE) with validated predictive equations based on anthropometry is limited. To our knowledge no studies exist for non-Caucasian populations OBJECTIVE: To design and validate an anthropometry-based equation to estimate TDEE using doubly-labelled water (DLW) as the criterion measure, and to assess the performance of three other published equations in community-living older people from rural and urban areas of Brazil, Chile, Guatemala, Senegal, Cuba, and Mexico METHODS: This cross-sectional study measured anthropometry and TDEE using DLW in 69 men and 43 women aged 60-89 years. TDEE was also estimated with an anthropometry-based equation derived from the sub-sample of Mexico (n = 38) and with three other published equations. Predictive accuracy of the equations was tested by an external validation procedure RESULTS: TDEE by DLW in the six country sample was 2411 ± 41 kcal/day (mean ± SE) in men and 1939 ± 51 kcal/day in women. The best new Mexican equation was TDEE, kcal/d = [223.4 + (27.9 × weight, kg) + (239.7 × sex)]; where sex: Man = 1 and Woman = 0; having high precision; R2 = 0.89, lowest RMSE = 149.2, and Cp value of 2.0. This new Mexican equation estimated TDEE accurately in the five country sample and at country level after correction for Guatemalan older men, while the published equations performed poorly CONCLUSIONS: The Mexican equation performed better that other published equations and is recommended to accurately estimate energy requirements for community-living older people in five Latin American and one African country.