"Exercise and diet are the two most profound and easy-to-implement interventions in our environment that can reduce our cardiovascular risk," he said. "There are not five drugs on the market once combined that could approach what we saw in this study from a moderate caloric restriction."
How a caloric restriction could protect the heart
The study involved 218 healthy adults, aged 21 to 50, spread across three clinical centers across the United States. Between 2007 and 2010, 143 of these adults were randomly assigned to start a 25% calorie restriction diet – which means they tried to cut their usual consumption by 25% – while the remaining 75 Adults have followed a "ad libitum" diet or "free diet" diet, which means that they eat normally.
Researchers in the caloric restriction group reduced their calorie intake by 11.9%, and not the 25% predicted, went from 2,467 calories per day to 2,170, a reduction of 297 calories.
"This trial lasted two years, so some participants were able to maintain the restrictions and others did not have the same success," Kraus said.
In each group, the researchers closely monitored each adult's cholesterol, blood pressure, and triglyceride levels over a two-year period. These factors can affect your risk of heart disease.
The researchers found that in the caloric restriction group, total cholesterol and LDL cholesterol levels dropped significantly after one year and that the change was maintained at two years, while the changes were very low in the ad libitum group.
The researchers also found that in the caloric restriction group, the drop in blood pressure was evident as early as six months, had statistical significance for one year, and persisted throughout the duration of the study.
This study is the first of its kind to study the potential impact of caloric restriction on the cardiovascular health of healthy, non-obese adults, young adults and middle-aged adults, the researchers wrote.
"It would be interesting to see what will happen to candidates for this study two years after the end of the study, whether they maintain these habits or not," said Dr. Subbarao Myla, director cardiac cardiac laboratories at Hoag Memorial Hospital Presbyterian in Newport Beach, California, who did not participate in the study.
Myla, who described the study as "well-designed," pointed out that during the study, participants had benefited from behavioral counseling sessions to help them adhere to their diet.
"All diet plans focus on two-tiered portion control – what you put on the plate and how much you eat," he said. "Having a life coach who can monitor, push and give a hand is very important to maintain change."
"Finally, none of this works without controlling the activity," said Myla, referring to physical activity or exercise. "The study did not address activity measures that are very difficult to control.Loss weight is best supplemented and maintained by increased activity."
"Food choices are shaped by the food environment"
"As individual food choices are shaped by the food environment, the long-term sustainability of caloric restriction and its benefits on body weight can be easily compromised," Hu wrote in the editorial.
"Therefore, improving the food environment by making healthy food choices more accessible, affordable and consistent with the standard while reducing the accessibility of ultra-processed and highly appetizing foods is essential to support healthy food choices, "he wrote. "To this end, policy solutions including sugar taxes, financial incentives for the production and purchase of healthy foods, food labeling and better regulation of product marketing are needed to improve the global food environment. "