Moderate caloric restriction for 2 years may modify several cardiovascular risk factors — including blood pressure, lipid profile, inflammatory markers, metabolic syndrome, and glucose homeostasis — in young and middle-aged healthy individuals, according to study results published in The Lancet Diabetes & Endocrinology.
In the 2-year multicenter randomized controlled CALERIE trial (Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy; ClinicalTrials.gov Identifier: NCT00427193), researchers aimed to assess the effect of calorie restriction on resting metabolic rate and body core temperature. The objective of the current study was to assess the short- and long-term effects of a 25% calorie restriction regimen on cardiometabolic risk factors in healthy young and middle-aged (21-50 years) participants without obesity.
Of the 238 patients recruited for the study, 218 started the assigned randomized intervention. A total of 143 were randomly assigned to moderate calorie restriction diet, of whom 117 completed the study. For the ad libitum control diet, 75 patients were assigned and 71 completed the study.
During the first 6 months, the mean reduction in energy intake was reduced by 19.5%±0.8% (480 kcal/d) in the calorie-restriction group, but decreased over time to an average reduction over the entire 2-year period of 11.9%±0.7%. Conversely, in the control group, there was no change in average daily energy intake over the study period. In a similar fashion, while the calorie restriction group had a sustained weight reduction of 7.5±0.3 kg (10.4%) and fat mass decrease of 5.3±0.3 kg over 2 years, the control group had no significant change in weight or fat mass.
Compared with the control diet, moderate calorie restriction was associated with persistent and significant improvements in multiple cardiometabolic risk factors at 2 years, including systolic (P <.0011) and diastolic (P <.0001) blood pressure, high-density lipoprotein cholesterol level (P =.0065), low-density lipoprotein cholesterol level (P <.0001), insulin resistance and glucose control (P <.0001), metabolic syndrome score (P <.0001), and chronic inflammation according to C-reactive protein levels (P =.012).
One of the major limitations of this study was the lack of clinical measurement of atherosclerotic plaque modifications.
“These data combined with previously published safety data for calorie restriction, indicate that inexpensive and safe dietary interventions, such as moderate calorie restriction, can be implemented early in life to [optimize] cardiometabolic health and reduce the lifetime risk of developing some of the most common, disabling, and expensive chronic diseases, such as hypertensive and atherosclerotic cardiovascular disease,” concluded the researchers.
Kraus WE, Bhapkar M, Huffman KM, et al. 2 years of calorie restriction and cardiometabolic risk (CALERIE): exploratory outcomes of a multicentre, phase 2, randomised controlled trial [published online July 11, 2019]. Lancet Diabetes Endocrinol. doi:10.1016/S2213-8587(19)30151-2