Effect of Two-Year Caloric Restriction on Bone Metabolism and Bone Mineral Density

Researchers randomly assigned 218 healthy, non-obese adults to either reduce their calorie intake or keep eating normally for two years. The calorie-restriction group aimed to eat 25% fewer calories, but achieved about a 12% reduction on average. Their bone mineral density, the amount of mineral packed into their bones, fell more at the hip and thigh bone than in the comparison group. Blood tests also suggested that bone breakdown and rebuilding became more active. The study did not show whether these changes led to more broken bones.

What this means for you: Long-term calorie cutting may reduce bone strength, especially at the hips, even in healthy adults. If you are considering substantial weight loss, do not ignore calcium, vitamin D, and strength exercise, and discuss a safe plan with a clinician.