Bone mineral density of overweight sedentary women chronically consuming low calcium diets

Abstract

Previous reports suggest that being overweight helps preserve bone mineral density (BMD) in women. Exercise and ethnicity can also influence bone preservation. The objective of this study was to investigate the relationship between BMD and low calcium diets in overweight sedentary women. Measures of lumbar spine (LS), hip and total body BMD were obtained by DXA in 3 African American and 5 Caucasian females between the ages of 33–43. Two dietary recalls were obtained by a multi‐pass approach using Nutrition Data System software. Mean body mass index was 28.2 ± 0.6 kg/m2. LS BMD was 1.28 ± 0.04 g/cm2 with a T‐Score of 0.7 ± 0.3. Total body BMD was 1.22 ± 0.03 g/cm2 and total hip BMD was 1.04 ± 0.04 g/cm2. Mean BMDs were within normal limits. T‐Scores for total body BMD and total hip BMD were 1.2 ± 0.3 and 0.3 ± 0.3 respectively. Mean calcium intake was 533 ± 50 mg/d. Correlations were examined between calcium intake and LS BMD (r = −0.65; p = 0.08), total hip BMD (r = −0.34; p = 0.41), and total body BMD (r = −0.51; p = 0.20). Until we attain our larger, final sample size, these data suggest a trend toward a relationship between low calcium intake and low LS BMD in a diverse ethnic sample. While these findings are preliminary in nature, they suggest that being overweight may not protect LS BMD when calcium intake is low in sedentary women. Exercise and adequate calcium intake remain prudent strategies for osteoporosis prevention.