Here is something that should send couch potatoes among girls to the running track. A study has established the link between loss of bone density and a sedentary life.

The study conducted on 186 girls from Delhi University — including those who are into sports — shows that only 1% of non–sportswomen meet the recommended dietary allowance for calcium, a major factor for bone strength. Their exposure to sunlight is also less than required, putting them at higher risk for bone loss after they turn 50.

Doctors advise that girls should exercise more and eat healthy during adolescence because that is the time when bones develop. Decline in bone strength starts after 30 years.

“Approximately 40% of bone acquisition takes place during adolescence, which protects against post–menopausal osteoporosis or bone loss. Our study highlights the need for girls to indulge in physical activity and focus on a healthy diet during this period so that they develop strong bones. Fragility fractures in women and bone loss is common these days,” said Dr Nikhil Tandon, professor endocrinology and metabolism at AIIMS, who headed the study. Institute of Nuclear Medicine and Allied Sciences, and Institute of Home Economics, DU, also participated.

Tandon said two groups of students were formed for the study. One had 90 sportswomen from Gargi College, Kamala Nehru College, Jesus and Mary College and Mata Sundri College. The second group had 96 girls from Sur Homeopathic Medical College, who were involved in less than 150 minutes of physical activity per week, including walking to college. “Blood samples were taken to assess their estimation of total serum calcium and serum ionic calcium phosphorus, among other clinical parameters. Dietary information was collected using 24–hour dietary recall,” he said. “Sportswomen showed significantly higher intake of all nutrients — energy, protein, carbohydrate and fat — as compared to other women. Only 2.1% girls in nonsports category could meet the dietary allowance recommended by Indian Council of Medical Research for energy compared to 47% of the sportswomen,” Tandon said.

Bone mineral density was also less in girls who did not participate in physical activities. “Today’s generation mostly remains indoors. Recreational activities for them are facebooking and chatting. Girls avoid stepping out in the sun and when they do, it is only after applying sunscreen lotion,” said Dr Seema Puri, who teaches at the Institute of Home Economics. “Sunshine is a major source of Vitamin D. As girls do not workout regularly, their dietary intake is poor compared to sportswomen. Such girls are more prone to developing osteoporosis,” she said.