Is Caloric Restriction Associated with Better Healthy Aging Outcomes? A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Nutrients
Q1
Jul 2020
Citations:34
Influential Citations:1
Systematic Reviews / Meta-Analyses
87
S2 IconPDF Icon

Enhanced Details

Methods
Eight randomized controlled trials in adults (≥18 years) with overweight/obesity or metabolic risk; total 704 participants; 67.9% women; follow-up 3 to 24 months.
Intervention
Caloric restriction diet: reduce daily energy intake by 20-30% of energy requirements (estimated ~1600 kcal/day for women and ~2000 kcal/day for men), taken as a daily diet for 3 to 24 months; some trials implemented CR with or without accompanying exercise.
Results
CR produced weight loss of about 7.9 kg, BMI −2.68 kg/m2, fat mass −4.40 kg. Total cholesterol decreased by ~12.72 mg/dL and LDL by ~22.03 mg/dL. Fasting insulin fell by ~2.76 mIU/L and fasting glucose by ~1.31 mg/dL. HDL and blood pressure effects were inconsistent; hormonal/metabolic changes included lower leptin and thyroid hormones (T3, T4) with higher ghrelin and adiponectin; IGF-1/IGFBP-1 ratio decreased. Mood and quality of life improved in some trials. Conclusion: CR is associated with improved cardiometabolic status in adults, especially overweight individuals, but evidence for broader health dimensions is limited and long-term effects require more high-quality studies.
Limitations
Small number of trials; short follow-ups; heterogeneity in CR definitions and outcomes; some baselines were imbalanced; risk of bias in several trials; largely North American samples; potential publication bias; limited data on bone health, other hormones, inflammation; lack of long-term safety data.

Abstract

Background: Global dietary patterns have gradually shifted toward a ‘western type’ with progressive increases in rates of metabolic imbalance. Recently, animal and human studies have revealed positive effects of caloric restriction (CR) on many healt...