Affiliation:
1. Department of Industrial Food Engineering, Basic Science Faculty Islamic Azad University Kazerun Iran
2. Islamic Azad University, Rasht Branch Rasht Iran
3. School of Medical Sciences Shiraz University of Medical Sciences Shiraz Iran
4. Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics Tehran University of Medical Sciences Tehran Iran
5. Department of Sports Physiology Semnan University Semnan Iran
6. Nutrition Research Center, School of Nutrition and Food Sciences Shiraz University of Medical Sciences Shiraz Iran
7. Department of Nutrition, School of Health Yasuj University of Medical Sciences Yasuj Iran
8. Department of Biochemistry University of KwaZulu‐Natal (Westville Campus) Durban South Africa
Abstract
SummaryBackground and ObjectiveAlmond consumption has an inverse relationship with obesity and factors related to metabolic syndrome. However, the results of available clinical trials are inconsistent. Therefore, we analyzed the results of 37 randomized controlled trials (RCTs) and evaluated the association of almond consumption with subjective appetite scores and body compositions.MethodsNet changes in bodyweight, body mass index (BMI), waist circumference (WC), fat mass (FM), body fat percent, fat‐free mass (FFM), waist‐to‐hip ratio (WHR), visceral adipose tissue (VAT), and subjective appetite scores were used to calculate the effect size, which was reported as a weighted mean differences (WMD) and 95% confidence interval (CI).ResultsThis meta‐analysis was performed on 37 RCTs with 43 treatment arms. The certainty in the evidence was very low for appetite indices, body fat percent, FFM, VAT, and WHR, and moderate for other parameters as assessed by the GRADE evidence profiles. Pooled effect sizes indicated a significant reducing effect of almond consumption on body weight (WMD: −0.45 kg, 95% CI: −0.85, −0.05, p = 0.026), WC (WMD: −0.66 cm, 95% CI: −1.27, −0.04, p = 0.037), FM (WMD: −0.66 kg, 95% CI: −1.16, −0.17, p = 0.009), and hunger score (WMD: −1.15 mm, 95% CI: −1.98, −0.32, p = 0.006) compared with the control group. However, almond did not have a significant effect on BMI (WMD: −0.20 kg m−2, 95% CI: −0.46, 0.05, p = 0.122), body fat percent (WMD: −0.39%, 95% CI: −0.93, 0.14, p = 0.154), FFM (WMD: −0.06, 95% CI: −0.47, 0.34, p = 0.748), WHR (WMD: −0.04, 95% CI: −0.12, 0.02, p = 0.203), VAT (WMD: −0.33 cm, 95% CI: −0.99, 0.32), fullness (WMD: 0.46 mm, 95% CI: −0.95, 1.88), desire to eat (WMD: 0.98 mm, 95% CI: −4.13, 2.23), and prospective food consumption (WMD: 1.08 mm, 95% CI: −2.11, 4.28). Subgroup analyses indicated that consumption of ≥50 g almonds per day resulted in a significant and more favorable improvement in bodyweight, WC, FM, and hunger score. Body weight, WC, FM, body fat percent, and hunger scores were decreased significantly in the trials that lasted for ≥12 weeks and in the subjects with a BMI < 30 kg/m2. Furthermore, a significant reduction in body weight and WC was observed in those trials that used a nut‐free diet as a control group, but not in those using snacks and other nuts. The results of our analysis suggest that almond consumption may significantly improve body composition indices and hunger scores when consumed at a dose of ≥50 g/day for ≥12 weeks by individuals with a BMI < 30 kg/m2.ConclusionHowever, further well‐constructed randomized clinical trials are needed in order ascertain the outcome of our analysis.