Imagine you're at a business meeting that your identical twin is also attending. Both of you are are of normal weight. There is a plate of cookies on the boardroom table. Your identical twin feels hungry, has a cookie and fully engages in the meeting. You, on the other hand, spend the meeting thinking: 'Gee, the cookies look awfully good. I bet they have about 300 calories. What have I eaten so far today? Do I have time to go to the gym later?' Eventually, you have a cookie.

In the scenario above, your twin has low cognitive dietary restraint - meaning she doesn't think about food much and eats when she feels like it. You, on the other hand, are showing signs of high cognitive dietary restraint. "You're giving lots of thought to your decisions around food," says Dr. Susan Barr of the University of British Columbia. "You're constantly monitoring and trying to limit food intake to either achieve or maintain your desired weight."

Dr. Barr, a Canadian Institutes of Health Research supported researcher, is leading a four-year study tracking food attitudes to gauge the health impacts of high levels of dietary restraint, which affects about 25% of women - regardless of their body weight. Previous research by Dr. Barr and her colleagues has shown that normal-weight women with high restraint are more likely to have menstrual cycle disturbances, affecting their chances of becoming pregnant. They also have higher levels of the stress hormone cortisol, which has been linked to diminished bone density and higher blood pressure.

But here's the kicker: while all that stressing over food may be putting women at higher risk of poor health, it doesn't appear to help them be slim.

Dr. Barr is in the process of analyzing the health impacts of worrying too much about what you eat. If the impacts are significant, her research will be important in developing ways to help women adopt new behaviours. "Is there some way of intervening with women to help them be less concerned about food? That's what we will be looking at down the road."

The Study

Because most of the previous work on dietary restraint has focused on young women, the first part of the study focused on learning more about dietary attitudes and restraint in postmenopausal women. Approximately 1,000 women completed questionnaires at baseline and two years later about their dietary habits, attitudes and behaviours. The questionnaire, designed to identify high cognitive dietary restraint behaviours in women, included questions such as:

How likely are you to consciously eat less than you want? Unlikely? Slightly likely? Moderately likely? Very likely?

In the second part of the study, approximately 70 postmenopausal women and 120 university-aged women participated in intensive follow-up studies in which measurements of their cortisol, bone density and blood pressure were recorded to gauge health impacts of high levels of dietary restraint over time. The data collection is near completion and the results will be analyzed to see if these women are at higher risk of poor health.

Canadian Institutes of Health Research