Is Caloric Restriction Associated with Better Healthy Aging Outcomes? A Systematic Review and Meta-Analysis of Randomized Controlled Trials
What this study found
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…
- Study & population
- 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.
- Key limitation
- 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.
View source
Open PDFOriginal 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 health domains, giving new knowledge for prevention of ill and health promotion; Methods: We conducted a systematic review (SR) of randomized controlled trials (RCTs) investigating the role of CR on health status in adults. A meta-analysis was performed on anthropometric, cardiovascular and metabolic outcomes; Results: A total of 29 articles were retrieved including data from eight RCTs. All included RCTs were at low risk for performance bias related to objective outcomes. Collectively, articles included 704 subjects. Among the 334 subjects subjected to CR, the compliance with the intervention appeared generally high. Meta-analyses proved benefit of CR on reduction of body weight, BMI, fat mass, total cholesterol, while a minor impact was shown for LDL, fasting glucose and insulin levels. No effect emerged for HDL and blood pressure after CR. Data were insufficient for other hormone variables in relation to meta-analysis of CR effects; Conclusion: CR is a nutritional pattern linked to improved cardiometabolic status. However, evidence is limited on the multidimensional aspects of health and requires more studies of high quality to identify the precise impact of CR on health status and longevity.