A modest reduction in energy intake from food of 200 calories per day — combined with moderate aerobic exercise — was linked to an improvement in cardiovascular health in older adults with obesity, according to a new study published in the journal Circulation.
Researchers were interested in looking at the effects of moderate exercise on body weight and other health-related measures in a group of 160 men and women ages 65 to 79, all of whom were obese. These participants were divided into one of three study groups. The first group did aerobic exercise training only — 30 minutes on a treadmill at 65% to 70% of heart rate reserve, four days per week. The second group did also this aerobic exercise, and also reduced their energy intake by 200 calories per day. The third group did the aerobic exercise and reduced their energy intake by 600 calories per day, and each intervention lasted for 20 weeks.
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All participants underwent a number of measurements before and after the 20 weeks, including their body weight and body fat distribution. They also underwent magnetic resonance imaging (MRI) to measure the blood flow rate (pulse wave velocity) and flexibility (distensibility) of their aorta, the major artery that begins in the heart.
Cutting 200 calories linked to weight loss, additional health benefits
The researchers found that in the group that cut their energy intake by 200 calories daily, participants lost an average of 8.0 kilograms (17.6 pounds) of body weight, while the group that cut 600 calories daily lost an average of 8.98 kilograms (19.8 pounds). The group that did only aerobic exercise lost an average of only 1.66 kilograms (3.65 pounds). These results demonstrate that cutting 200 calories led to nearly as much weight loss as cutting 600 calories. Both groups also saw large improvements in total fat mass, body fat percentage, waist circumference, and abdominal fat that corresponded with weight loss.
But weight loss wasn’t the only major benefit seen in the group that cut 200 calories — these participants also experienced an average 21% increase in aortic flexibility, along with an 8% decrease in the rate of blood flow. No significant improvements in these measures were seen in either of the other groups, which demonstrated that weight loss alone wasn’t responsible for this improvement in cardiovascular health.
“This is the first study to assess the effects of aerobic exercise training with and without reducing calories on aortic stiffness,” said study author Tina E. Brinkley, PhD, 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 Winston-Salem, North Carolina, in a press release. “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.”
These results, Brinkley noted, suggest that combining moderate exercise with a moderate reduction in caloric intake — rather than a more drastic approach to cutting calories — may be the best way to achieve sustained weight loss while improving cardiovascular health in older adults with obesity. More research is needed to find out whether similar findings apply to other groups, such as younger adults or those who are overweight but not obese.