Although it is widely accepted that adequate calcium intake is essential for maximal development of bone mass during childhood and adolescence, concern exists that high calcium diets may lead to excessive weight gain. The purpose of this analysis is to determine if pubertal females on high calcium diets experience significantly greater increase in body mass index (BMI) than pubertal females on their usual calcium intakes. This analysis was conducted on data accrued during an experimental study to test the effect of increasing dietary calcium intake to 1500 mg/day on increases in bone quality in pubertal females. The intervention for this report is high calcium diet while the outcome variable is change in BMI. Participants were nine years of age and in Tanner pubertal stage 1 upon entry into study. Girls with BMI equal to or greater than the 85th percentile for age and gender were excluded. The sample includes 59 pubertal females (mean age 11.5 plus/minus 0.3 years) who completed three years of study. The 27 girls in the treatment group are directed to consume 1500 mg of calcium from food per day, while the 32 girls in the control group are asked to continue on their usual diets. The participants are allowed to use calcium-fortified foods but not calcium supplements. The study provides the high calcium foods. Each family is given an expense card to be used at a local supermarket for purchase of dairy and calcium-fortified foods. Participants are asked to come to the research center quarterly for study visits. Dietary calcium intake is determined by diet diaries completed quarterly by the girls and their parents. The girls in the high calcium group also record their calcium intake daily. Height is determined with a Harpenden stadiometer, and weight is obtained with a balance scale. BMI is calculated as weight in kilograms/height in meters*height. The control group consumed an average of 881 mg of calcium/day while the treatment group consumed an average of 1559 mg/day. Two-tailed t-tests indicate no significant differences between the treatment and control groups in rate of change in BMI from baseline to the three-year measurement. Thus, we conclude that high dietary calcium is not contributing to excessive weight gain in this group of girls. This has implications for professionals providing bone health information to girls and their parents. Clients should be encouraged that ingesting optimum levels of dietary calcium to maximize bone health will not lead to unhealthy weight gain.
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