DALLAS, Texas — Counting calories is not only good for helping with weight loss, it may help older adults improve their heart health too, a new study finds. Researchers with the American Heart Association say obese seniors who cut out just 250 calories a day and do some moderate exercise enjoy better heart function than older adults who just focus on exercising.
Surprisingly, the findings also reveal that obese adults who cut their calorie count even further don’t experience any added health gains from dieting. Patients on the less strict diet who also exercised four times a week displayed the greatest improvements in their weight and aortic stiffness after five months. Aortic stiffness measures vascular health and is a key predictor of cardiovascular disease.
“This is the first study to assess the effects of aerobic exercise training with and without reducing calories on aortic stiffness, which was measured via cardiovascular magnetic resonance imaging (CMR) to obtain detailed images of the aorta,” says lead author Tina E. Brinkley, Ph.D., an associate professor of gerontology and geriatric medicine at the Sticht Center for Healthy Aging and Alzheimer’s Prevention at Wake Forest School of Medicine, in a media release.
“We sought to determine whether adding caloric restriction for weight loss would lead to greater improvements in vascular health compared to aerobic exercise alone in older adults with obesity.”
Modest lifestyle changes with big results
Study authors examined 160 obese adults with a sedentary lifestyle between 65 and 79 years-old. The team notes their volunteers were predominantly female (74%) and white (73%). Researchers split those seniors into three groups for 20 weeks, one focusing on exercise and enjoying a regular diet, one doing moderate exercise and cutting out 250 calories a day, and one group exercising and cutting out 600 calories.
Scientists measured the function of the aorta using MRI scans. These tests revealed each person’s aortic arch pulse wave velocity (PWV), which is the speed at which blood moves through a patient’s aorta. The tests also gauged the ability of the aorta to expand and contract, which doctors call distensibility.
After five months of aerobic exercise and moderate calorie restriction, the results show obese seniors dropping their calorie count by 250 a day lost nearly 10 percent of their body weight. On average, that added up to about 20 pounds over the 20 weeks. Moreover, these participants saw a 21-percent increase in distensibility and an eight-percent decrease in PWV levels.
Overly restrictive diets not necessary?
Despite cutting out more than double the calories, seniors in the intensive calorie restriction group did not experience any added benefits in aortic stiffness.
“We were surprised to find that the group that reduced their calorie intake the most did not have any improvements in aortic stiffness, even though they had similar decreases in body weight and blood pressure as the participants with moderate calorie restriction,” Brinkley adds.
“These results suggest that combining exercise with modest calorie restriction — as opposed to more intensive calorie restriction or no-calorie restriction — likely maximizes the benefits on vascular health, while also optimizing weight loss and improvements in body composition and body fat distribution. The finding that higher-intensity calorie restriction may not be necessary or advised has important implications for weight loss recommendations to improve cardiovascular disease risk in older adults with obesity.”
The study appears in the journal Circulation.