Cutting 300 calories daily protects heart health, study says
Reducing caloric intake by about 300 calories a day can significantly improve already good levels of cholesterol, blood pressure, blood sugar, and other biomarkers in adults already at a health weight or slightly overweight, according to a new study published in The Lancet Diabetes & Endocrinology.
The trial, part of an ongoing project with the National Institutes of Health called the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE) build on the researchers' hypothesis that it's not just weight loss that leads to these improvements, but some more complex metabolic change triggered by eating fewer calories than what's expended, according to William Kraus, MD, lead author and cardiologist and professor at Duke University Medical Center in Durham, North Carolina.
"There's something about caloric restriction, some mechanism we don't yet understand that results in these improvements," said Kraus in a statement. "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."
For the first month of the trial, participants ate three meals a day that would cut one-fourth of their daily calories to help train them on the new diet. They could choose from six different meal plans that accommodated cultural preferences or other needs. Participants also attended group and individual counseling sessions for the first six months of the trial, while members of a control group simply continued their usual diet and met with researchers once every six months.
Participants were asked to maintain the 25 percent calorie reduction for two years. Their ability to do so varied, with the average calorie reduction for all participants being about 12 percent. Still, they were able to sustain a 10-percent drop in their weight, 71 percent of which was fat, according to the study abstract.
There were numerous improvements in markers that measure risk for metabolic disease. After two years, participants also showed a reduction in a biomarker that indicates chronic inflammation which has also been linked to heart disease, cancer, and cognitive decline, said Kraus.
"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 this country," Kraus said. "People can do this fairly easily by simply watching their little indiscretions here and there, or maybe reducing the amount of them, like not snacking after dinner."