Reducing Daily Calories by 200, Exercise Associated With Heart Health Improvements in Obese Older Adults

New research from the American Heart Association (AHA) has found that cutting just 200 calories a day combined with moderate exercise had more of a benefit than exercise alone for older obese adults. Additionally, among this population, combining aerobic exercise with a moderate reduction in daily calories resulted in greater improvements in aortic stiffness versus exercise only or exercise plus a more restrictive diet.

Modifiable lifestyle factors, such as a healthy diet and regular physical activity, may help balance age-related increases in aortic stiffness. Although aerobic exercise generally has favorable effects on aortic structure and function, previous studies have shown that exercise alone may not be sufficient to improve aortic stiffness in older adults with obesity, according to the AHA.

“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 to obtain detailed images of the aorta,” said Tina E. Brinkley, PhD, lead author of the study, in a press 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.”

The controlled trial included 160 sedentary adults between 65 and 79 years of age with obesity, with 74% being female and 73% being white. The participants were randomly assigned to 1 of 3 intervention groups for 20 weeks: exercise only with their regular diet, exercise plus moderate calorie restriction (reduction of approximately 250 a day), or exercise plus more intensive calorie restriction (reduction of approximately 600 calories a day).

The 2 calorie-restricted groups received pre-made lunches and dinners with less than 30% of calories from fat and at least 0.8 grams of protein per kg of their ideal body weight. These meals were prepared under the direction of a registered dietitian, with participants making their own breakfasts according to the dietitian-approved menu. Further, all participants in the study received supervised aerobic exercise training 4 days per week for the duration of the 20-week study at the Geriatric Research Center at Wake Forest School of Medicine.

The results showed that weight loss of nearly 10% of total body weight or about 20 pounds over the 5-month study period was associated with significant improvements in aortic stiffness, only in the participants assigned to the exercise plus moderate calorie restriction group.

Some additional findings include:

• The exercise plus moderate calorie restriction group had a 21% increase in distensibility and an 8% decrease in pulse wave velocity.
• None of the aortic stiffness measures changed drastically in either the exercise-only group or the exercise plus more intensive calorie restriction group.
• Changes in body mass index, total fat mass, percent body fat, abdominal fat ,and waist circumference were greater in both of the calorie-restricted groups compared to the exercise-only group.
• Weight loss was similar between the calorie-restricted groups despite nearly 2 times fewer calories in the intensive calorie restriction group.

“Our findings indicate that lifestyle changes designed to increase aerobic activity and moderately decrease daily calorie intake may help to reduce aortic stiffness and improve overall vascular health,” Brinkley said in a press release. “However, 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 added that these results indicate that combining exercise with modest calorie restriction versus a 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,” Brinkley said in a press release.

REFERENCE

Cutting 200 calories daily and exercising may improve heart health in obese older adults. American Heart Association. August 2, 2021. Accessed August 2, 2021. https://newsroom.heart.org/news/cutting-200-calories-daily-and-exercising-may-improve-heart-health-in-obese-older-adults