Relationships among cognitive dietary restraint, subclinical ovulation disturbances, cortisol and 2‐yr change in bone density in premenopausal women

Cognitive dietary restraint (CDR) is the perception of limiting food intake to achieve/maintain a perceived ideal body weight. The objective of this 2‐yr prospective study was to determine if women with higher CDR have more subclinical ovulation disturbances (SOD; anovulation or luteal phase <10 d), elevated cortisol excretion and less positive changes in areal bone mineral density over two years (ΔaBMD). Participants were 123 healthy, non‐obese, regularly menstruating women aged 19–35. Annually participants completed questionnaires (Three Factor Eating Questionnaire, physical activity, general stress, dietary intake), anthropometrics and 24‐hr urine collections for measurement of 24‐hr urinary free cortisol (UFC). At baseline and final follow‐up, dual energy x‐ray absorptiometry scans measured ΔaBMD at the lumbar spine (L1‐4), hip and total body. Quantitative waking temperature was used to determine SOD frequency. SOD correlated positively with CDR and inversely with hip ΔaBMD but not with UFC. CDR and UFC were not associated with each other or ΔaBMD. Women with higher CDR had more SOD. Women with more SOD had less positive ΔaBMD and higher CDR. Physical activity, general stress, body mass and energy intake did not explain differences by CDR or SOD. In conclusion, CDR was the only study variable associated with SOD which was associated with less positive ΔaBMD. Canadian Institutes of Health Research 79563. Grant Funding Source : Canadian Institute of Health Research