Table 15.

Future research agenda

Topic area	What we need to know
Life stages of growth for interventions	Are interventions more effective during different stages of growth (e.g., rapid or slow)? Can deficiencies in one stage be overcome subsequently?
	Is there an influence of fetal programming?
	What are the most effective diet and physical activity interventions at each stage?
	What is the influence of diet and physical activity patterns, in the short-term and over long periods?
	What are the determinants of bone acquisition and the impact of interventions in the understudied period of late adolescence to early adulthood?
	Does response to intervention vary by factors such as sex and population ancestry?
	Are there other understudied or unstudied lifestyle or environmental factors affect peak bone mass development (i.e., sleep, stress, etc.)?
Gene–environment interactions	Are there interactions that affect peak bone mass development?
Biomarkers of exposure and effect	How do we generate better markers of nutritional status, physical activity and bone loading, and other environmental exposures?
	Among adolescents, exposures to consider include lifestyle habits such as smoking (both nicotine and marijuana) and alcohol, among others.
	How do we generate better markers of stage of maturity, peak bone strength development, and associated intermediate mechanisms?
	Attention to the multiple factors involved in bone and mineral metabolism is needed in interpreting responses to dietary interventions, including a focus on interactions between vitamin D, phosphorus, calcium, and fibroblast growth factor 23.
Organ and tissue interactions	What are bone interactions with other tissues (i.e., brain, fat, muscle, gut, etc.) on development of peak bone mass?