HealthDay News — Sustained calorie restriction can influence disease risk factors and possible predictors of longevity in healthy, non-obese people, according to a study published in the September issue of the Journal of Gerontology: Medical Sciences.
The research included 218 healthy adults, young or middle-aged, and either at normal weight or slightly overweight. They were randomly assigned to either a calorie restriction group or to a control group who continued their regular eating habits. The participants in the calorie restriction group were given a target of 15.5% weight loss in the first year, reducing their calorie intake by 25%. They were asked to keep their weight stable in the second year of the study.
The participants in the calorie restriction group showed significant improvements in several predictors of heart disease, including a 6% decrease in total cholesterol, a 4% fall in blood pressure, and increased levels of high-density lipoprotein (HDL) cholesterol. Calorie restriction also led to a 47% decrease in levels of C-reactive protein and reduced insulin resistance. Levels of triiodothyronine fell by more than 20%. Some studies have suggested that lower thyroid activity may be associated with longer life span.
Some of the participants in the calorie restriction group developed temporary anemia. Some also had larger-than-expected decreases in bone density, the researchers found. These findings highlight the importance of medical monitoring during calorie restriction, according to the study authors.
In a news release from the US National Institutes of Health, study author Evan Hadley, MD, director of the National Institute on Aging’s Division of Geriatrics and Clinical Gerontology, said it’s important to see if calorie restriction would offer additional long-term benefits. And, he added, it would be useful to learn if calorie-restricted weight loss offered more benefits than exercise-induced weight loss.