A prospective exploration of associations among cognitive dietary restraint, cortisol excretion, ovarian function and bone health in premenopausal women

About 16 per cent of Canadian women over age 50 have osteoporosis – a condition with low bone density that increases their risk of fracture. Osteoporosis costs the health system $1.3 billion annually, and both prevalence and costs are expected to rise in the next two decades as the population ages. Optimizing peak bone mass during women’s younger years is key to preventing osteoporosis. In western culture where thinness is idealized, many women experience body dissatisfaction. In response, women attempt to control their body size and weight, typically through diet and/or exercise. The eating attitudes of many women are characterized by high levels of cognitive dietary restraint (CDR) - the perception that one is constantly monitoring and attempting to limit food intake in an effort to control weight. While the adverse consequences of clinical eating disorders (e.g. anorexia nervosa) are well-recognized, the potential health effects of subtle disturbances of eating attitudes, such as high levels of CDR, are only beginning to receive researchers’ attention. Jennifer Bedford is studying whether these eating attitudes affect young women’s bone density. Previous research in the area suggests that women with high CDR have higher levels of the stress hormone, cortisol, which may negatively affect bone density directly by disrupting bone and calcium metabolism. It also affects bone indirectly by disturbing the menstrual cycle hormones, resulting in disturbances in ovarian function. Jennifer is conducting the first prospective study to examine the relationships between eating attitudes, cortisol levels, ovarian function and bone density in young women. The findings should lead to health and nutrition education strategies to inform young women of the potential health effects of their attitudes about food, eating and their bodies.