Contrary to the widespread belief that calorie restriction is only relevant for plumpy people, while the slim folks have no need for calorie reduction, a new study conducted by scientists from Duke University in Durham, NC, has recently found that healthy, slim people can benefit from cutting 300 calories a day from their diet.
The strategy could reduce the “devastation” of cardiovascular disease, diabetes and obesity, possibly boosting longevity, the authors wrote.
According to the findings reported on Journal the Lancet Diabetes & Endocrinology, people who followed the calorie-restriction diet for two years had a lower blood pressure, lower total cholesterol, lower risk of metabolic syndrome and improvements in insulin sensitivity.
The lead author of the study, Dr William E. Kraus a cardiologist and distinguished professor of medicine, and colleagues explained in their paper that some cardiometabolic markers such as cholesterol, blood pressure, and blood sugar can raise the risk of cardiovascular disease and cardiovascular death even when they are within ranges that healthcare professionals consider to be normal.
On the other hand, numerous studies have suggested that calorie restriction benefits both a person’s health span and life span. However, are these benefits due to weight loss?
The researchers started their new study from the hypothesis that it isn’t just losing weight, but also some other, more complex molecular mechanism that explains the benefits of calorie restriction for cardiometabolic health.
All the trial participants had an average body mass index (BMI) of between 22 and 27.9. To begin, the researchers randomly assigned them to one of two groups: one group reduced their caloric intake by 25 percent (the intervention group), and the other group did not change their caloric intake (the control group).
The participants in the intervention group ate three meals per day and were free to choose from six different meal plans. They also “attended group and individual counseling sessions for the first 6 months of the trial.” The study started in May 2007 and continued through to February 2010.
During this time, the remaining participants those in the control group continued to follow their regular diet.
Not all the participants in the intervention group managed to maintain a 25 percent calorie reduction throughout the study period, but they did reduce their intake by almost 12 percent, on average.
After the intervention, the participants in this group lost and maintained the loss of 10 percent of their weight 71 percent of which was fat mass. The calorie restriction resulted in significant cardiometabolic benefits.
Specifically, “Calorie restriction caused a persistent and significant reduction from baseline to 2 years of all measured conventional cardiometabolic risk factors,” wrote the authors. This included changes in low density lipoprotein cholesterol, high density lipoprotein (HDL) cholesterol, and systolic and diastolic blood pressure.
Also, “calorie restriction resulted in a significant improvement at 2 years in C-reactive protein.” This is a marker of inflammation that scientists have linked to heart disease, cancer, and cognitive decline. Insulin sensitivity and markers of metabolic syndrome also improved.
The benefits remained robust after Dr Kraus and team conducted a sensitivity analysis that adjusted the results for relative weight loss.
Dr William E. Kraus explained that “this shows that even a modification that is not as severe as what we used in this study could reduce the burden of diabetes and cardiovascular disease that we have in the United States.”
Dr Kraus also made it clear that his study examined biomarkers for a person’s health span, and he says that he and his colleagues were “impressed” by the “dramatic” improvements and “remarkably” positive effects that caloric restriction had on waist circumference, triglycerides, HDL cholesterol, glucose control, and blood pressure.