Study Explores Health Benefits of Nutrient-Filled Calorie-Restricted Diet

Introduction

Researchers conducted a two-year study to investigate the health advantages of a nutrient-rich, calorie-restricted diet. Cardiovascular disease continues to be the leading cause of mortality worldwide, with previous research indicating that calorie restriction can diminish the risks associated with atherosclerosis.

Objective of the Study

The primary question this study aimed to answer was: How does a two-year, nutrient-dense calorie restriction mitigate long-term cardiovascular risks in healthy individuals?

Study Overview

Published in The Lancet Diabetes & Endocrinology, the study involved participants in a controlled and randomized trial known as the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE). The participants, aged between 21 and 50 years, included both men and women who were deemed healthy, either slim or slightly overweight (non-obese).

Methodology

During the trial, the participants were divided into two groups. One group maintained their regular eating habits (the regular-diet group), while the other adopted a 25% calorie-restricted diet (the calorie-restricted group). For the first month, participants in the calorie-restricted group consumed three meals daily at a multicenter location, following specific meal plans to acclimatize to the new diet. Additionally, they received counseling during the first six months, whereas the regular-diet group had biannual consultations with the researchers.

The study included a variety of assessments before and after the trial, measuring factors such as body mass index, fat mass, insulin resistance, blood pressure, and blood samples. Participants’ energy intake and expenditure were also closely monitored.

Findings

The results indicated that the calorie-restricted group reduced their caloric intake by an average of 12%, equating to approximately 279 calories per day in the first year and 216 calories per day in the second year. This group experienced a 10% reduction in body weight, with over half of that weight loss attributed to fat. In contrast, the regular-diet group showed minimal weight loss.

The study revealed significant positive changes in metabolic disease risk factors among the calorie-restricted group. Notable reductions in risks for cancer, chronic inflammation, cognitive decline, and heart disease were observed. Additionally, LDL-cholesterol levels decreased significantly in the calorie-restricted group while showing only slight changes in the regular-diet group. Fasting glucose levels also declined.

Conclusion and Future Research

The strength of this study lies in its two-year duration and substantial sample size. The author emphasized that further research is essential to fully understand the health benefits of calorie restriction, particularly in healthy individuals. Additional studies are recommended to explore the implications of nourishing calorie restriction more comprehensively.

References

Even in svelte adults, cutting about 300 calories daily protects the heart. 2019, https://www.eurekalert.org/pub_releases/2019-07/dumc-eis071019.php, assessed 18 July 2019.
Kraus, William E., et al. “2 years of calorie restriction and cardiometabolic risk (CALERIE): exploratory outcomes of a multicentre, phase 2, randomised controlled trial”. The Lancet Diabetes & Endocrinology. 2019. 1-11. Online.

Written by Laura Laroche, HBASc, Medical Writer.