Food Restriction Adds Stress

Dieting may increase risks of bone loss and infertility

Women who restrict food intake for the purpose of dieting have higher levels of stress, according to research published in the American Journal of Clinical Nutrition (ACJN). That stress causes the body to release excess cortisol, which can cause serious health problems such as bone loss, decreased fertility, or heart disease.

College-aged women are especially vulnerable to societal or self-imposed pressure to attain or maintain a specific weight or body shape, according to a statement released by the Public Information Committee of the American Society for Nutritional Sciences.  Dieting women tend to make conscious decisions about trying to eat less rather than letting the body's hunger and satiety mechanisms govern their eating patterns.

"When it comes to good health and achieving and maintaining a healthy weight, changing your overall dietary pattern is more important than restricting any specific foods," stated Susan Barr, coauthor of the study. "Our study suggests that normal-weight women should enjoy 'eating well' rather than be excessively concerned about monitoring or limiting food intake."

Other scientists agree that 'eating well' can help prevent the development of chronic diseases. Authors from Harvard published a separate study in the AJCN - comparing dietary patterns and the relationship that diets high in fruits, vegetables, whole grains, fish, and poultry have on reducing fasting insulin and homocysteine levels. Diets high in red and processed meats, refined grains, and full-fat dairy products were, conversely, associated with higher levels of fasting insulin, leptin, homocysteine, and C-reactive proteins which can lead to serious health problems.  Eating prudently, according to the authors, raises plasma folate and reduces insulin and homocysteine concentrations in the body.

The take home message seems to indicate a need to change the typical focus of many chronic dieters from restricting intake to making better food choices.  When increases in fruit and vegetable consumption improve blood levels of micronutrients that are known to decrease risks of heart disease and cancer, it appears that it is more important what you eat than how little you eat when it comes to dieting for long-term health. 

McLean JA, Barr SI, Prior JC.  Cognitive dietary restraint is associated with higher urinary cortisol excretion in healthy premenopausal women. ACJN 73:7-12 
Fung TT, Association between dietary patterns and plasma biomarkers of obesity and cardiovascular disease risk. ACJN 73:61-67