Boosting Calcium Without Weight Gain
No Risk of Extra Pounds for Girls Eating Calcium-Rich Foods
Aug. 31, 2004 -- Bring on the calcium and don't worry about the scale. Young girls can eat calcium-rich foods without increasing their risk of gaining weight, according to Creighton University researchers.
Youth is a crucial time for building bones. Near-maximum or peak bone density occurs by age 18 and an adequate intake of calcium is necessary to attain and maintain healthy bones and prevent future risks of osteoporosis. But many young American girls don't get enough calcium in their diets. There are also concerns that dairy foods, which are rich in calcium, may lead to weight gain.
In fact, 9- to 13-year-old girls in the U.S. on average get 69% of the recommended calcium intake. The numbers are even lower for 14- to 18-year-old girls, who average getting 55% of the recommended level. The recommended intake of calcium for children and adolescent girls of this age is 1,300 milligrams per day.
Nursing and medicine professor Joan Lappe, PhD, RN, and colleagues studied 59 girls aged 9. Thirty-two were randomly assigned to a high-calcium diet; the rest ate normally.
The girls in the calcium group were told to consume at least 1,500 milligrams of calcium per day, and it had to come from food, not supplements. The average intake of calcium in the other group was 1,000 milligrams per day.
To help out, the researchers taught the girls and their parents how to pick calcium-rich or calcium-fortified foods and provided a "credit card" for purchases.
No Major Difference in Weight, Fat Mass in Calcium Group
Throughout the two-year study, the test group got more than 70% of their dietary calcium from dairy foods including milk, cheese, ice cream, and yogurt. They also ate calcium-fortified foods.
Every three months, the girls from both groups turned in their food journals and had their height, weight, physical activity, and health checked.
Bone mass and body composition (fat and muscle mass) were measured twice a year, and the researchers also tracked the girls' intake of 14 nutrients.
The results showed no significant difference between the groups in height, weight, BMI, muscle amount, or fat mass, even though the test group consumed nearly twice as much dietary calcium. Primarily their intake of calcium was from diary products.
They also boosted their intake of protein, vitamins A and D, phosphorus, potassium, and magnesium. In contrast, the girls in the comparison group only increased their iron and zinc.
All that extra calcium didn't break the bank. Overall, the families spent $9.81 per week to buy their calcium-rich foods.
The take-home message: "... calcium-rich diets do not increase the risk of excessive weight gain," write the researchers in the Journal of the American Dietetic Association.