Calorie restriction 'significantly' improves health in thin adults

A study out of Duke Health has found that eliminating approximately 300 calories from one's daily diet has a significant protective effect on health. This beneficial effect was found in adults who were a healthy weight or who had 'a few pounds' to lose, according to the researchers, spurring an improvement in health markers like blood pressure and blood sugar that were already in the 'good' range.

Duke Health has revealed the outcome of a recent trial it conducted as part of the National Institute of Health project CALERIE, which is focused on the idea that calorie restriction, not just weight loss, triggers the positive health changes associated with dieting. Duke Health's trial involved 218 adults who were under the age of 50.

During the first month of this trial, the participants ate three daily meals that reduced their daily caloric consumption by one-fourth, something intended to help them ease into the new diet. Over the next two years, the participants were instructed to eat at a 25-percent daily calorie reduction, though by the end they only averaged a 12-percent reduction over that time period.

Despite not quite hitting the 25-percent goal, the researchers report that the participants were collectively able to maintain a weight loss of 10-percent, the majority of which was caused by fat loss. As well, the participants were found to have improvements to a number of health markers associated with metabolic disease risk, including blood sugar, blood pressure, and cholesterol.

In addition, at the end of the study the participants were found to have lower levels of a biomarker that indicates the presence of chronic inflammation. As a number of past studies have revealed, chronic inflammation is a risk factor for serious long-term health issues, including the development of cancer, memory problems, and cardiovascular disease.

Despite the positive outcomes, the researchers point out that cutting 300 calories out of one's daily diet isn't terribly burdensome: it amounts to less than a medium order of french fries, for example.

The study's lead author, Duke professor of medicine and cardiologist William E. Kraus, MD, explained:

There's something about caloric restriction, some mechanism we don't yet understand that results in these improvements. We have collected blood, muscle and other samples from these participants and will continue to explore what this metabolic signal or magic molecule might be.