Skinny Dieters at Risk for Bone Loss (Journal of Nutrition Nov 2009)

PRLog (Press Release) - Nov 28, 2009 -
According to a recent study in the Journal of Nutrition, reduced bone density is more apparent in lean subjects compared to heavier subjects when diet is restricted.  Although the study was done on rats, it warrants attention especially for  individuals who are not obese.  This category of individuals include models, those fasting to detoxify, and those with eating disorders.

The goal of the study was to observe how bone density and geometry responded to dieting  (energy restricted diets).  During a 10 week diet (40% food restriction) obese rats lost more weight than the lean rats.  Three serum factors were measured in regards to bone synthesis: estradiol, calcefidiol and parathyroid hormone.  Estradiol is a major estrogen in humans that affects reproductive organs and bones. Calcefediol, a precursor to active vitamin D undergoes hydroxylation in the liver and is the most sensitive indicator to vitamin D status in the blood. Parathyroid hormone (PTH) is secreted by the parathyroid gland and is responsible for increasing calcium concentration in the blood.

Overall results revealed reduced blood serum levels in lean rats for estradiol, calcefidiol and parathyroid hormone which may have contributed to bone loss. The research suggested that bone metabolism was greatly affected by dietary energy restriction (fasting or dieting) in lean rats.  Clinical trials on humans are yet to confirm.

Log onto http://www.foodinformantonline.com/ for the latest on how to keep your bones healthy.


RESOURCE:
Jaleah Hawkins, Mariana Cifuentes, Nancy L. Pleshko, Hasina Ambia-Sobhan4 and Sue A. Shapses; Nutrition and Disease:  Energy Restriction Is Associated with Lower Bone Mineral Density of the Tibia and Femur in Lean but Not Obese Female Rats: J. Nutr. (November 18, 2009). doi:10.3945/jn.109.111450
© 2009 American Society for Nutrition