Effect of nuts on components of metabolic syndrome in healthy adults with overweight/obesity: A systematic review and meta-analysis


      • Effects of nut consumption on components of metabolic syndrome were summarized.
      • Nut consumption led to a significant reduction in some components of lipids profile.
      • Nut intake had no effect on glycemic markers and blood pressure.



      Randomized controlled trials evaluating the effects of nut consumption on the metabolic profile of healthy adults with overweight/obesity have yielded conflicting results. This systematic review and meta-analysis aimed to summarize the effects of incorporating nuts into the diet on serum lipid profile, glycemic markers, and blood pressure in healthy adults with overweight/obesity.

      Data synthesis

      PubMed, Embase, Scopus, Web of Science, and Cochrane Library were searched up to April 2021. The random-effects model was used to determine the pooled effect sizes expressed as weighted mean difference (WMD) with % 95 confidence intervals (CIs). Ten eligible RCTs (with 12 arms) were included in the meta-analysis. The meta-analysis revealed that nut intake significantly decreased serum triglycerides (TG) (WMD: -13.19 mg/dL, 95% CI: - 25.90, - 0.48). Furthermore, subgroup analysis showed a significant reduction in serum LDL-cholesterol (LDL-C) following adherence to normocaloric, nut-enriched diets (WMD: - 4.56 mg/dL, 95% CI: - 8.24, - 0.88). However, nuts did not affect serum total cholesterol, high-density lipoprotein cholesterol, glycemic markers, and blood pressure.


      Overall, incorporating nuts into the diet of healthy adults with overweight/obesity have favorable effects on serum TG and LDL-C. Thus, nuts might exert protective effects against dyslipidemia in this population.

      Registry number

      PROPSPERO CRD42021250662.


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        • WHO
        Obesity and overweight: World health organization.
        ([Available from:)
        • Fruh S.M.
        Obesity: risk factors, complications, and strategies for sustainable long-term weight management.
        J Am Assoc Nurse Pract. 2017; 29: S3-S14
        • Hruby A.
        • Hu F.B.
        The epidemiology of obesity: a big picture.
        Pharmacoeconomics. 2015; 33: 673-689
        • Smethers A.D.
        • Rolls B.J.
        Dietary management of obesity: cornerstones of healthy eating patterns.
        Med Clin. 2018; 102: 107-124
        • Rolls B.J.
        Dietary energy density: applying behavioural science to weight management.
        Nutr Bull. 2017; 42: 246-253
        • Souza R.G.
        • Gomes A.C.
        • Naves M.M.
        • Mota J.F.
        Nuts and legume seeds for cardiovascular risk reduction: scientific evidence and mechanisms of action.
        Nutr Rev. 2015; 73: 335-347
        • Bazshahi E.
        • Sheikhhossein F.
        • Amini M.R.
        • Shab-Bidar S.
        The association of dietary energy density and the risk of obesity, type 2 diabetes and metabolic syndrome: a systematic review and meta-analysis of observational studies.
        Int J Clin Pract. 2021; 75e14291
        • Stopyra M.A.
        • Friederich H.C.
        • Lavandier N.
        • Mönning E.
        • Bendszus M.
        • Herzog W.
        • et al.
        Homeostasis and food craving in obesity: a functional MRI study.
        Int J Obes. 2021; 45: 2464-2470
        • DGA
        U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015 – 2020 dietary guidelines for Americans.
        • Hassannejad R.
        • Mohammadifard N.
        • Kazemi I.
        • Mansourian M.
        • Sadeghi M.
        • Roohafza H.
        • et al.
        Long-term nuts intake and metabolic syndrome: a 13-year longitudinal population-based study.
        Clin Nutr. 2019; 38: 1246-1252
        • Hosseinpour-Niazi S.
        • Hosseini S.
        • Mirmiran P.
        • Azizi F.
        Prospective study of nut consumption and incidence of metabolic syndrome: tehran lipid and glucose study.
        Nutrients. 2017; 9
        • Jaceldo-Siegl K.
        • Haddad E.
        • Oda K.
        • Fraser G.E.
        • Sabaté J.
        Tree nuts are inversely associated with metabolic syndrome and obesity: the Adventist health study-2.
        PLoS One. 2014; 9: e85133
        • Kim R.J.
        • Wang L.
        • Worley S.
        • Leonard D.
        Nut consumption and metabolic syndrome in US adolescents.
        Publ Health Nutr. 2018; 21: 3245-3252
        • O'Neil C.E.
        • Fulgoni 3rd, V.L.
        • Nicklas T.A.
        Tree Nut consumption is associated with better adiposity measures and cardiovascular and metabolic syndrome health risk factors in U.S. Adults: nhanes 2005-2010.
        Nutr J. 2015; 14: 64
        • Mohammadifard N.
        • Haghighatdoost F.
        • Mansourian M.
        • Hassannejhad R.
        • Sadeghi M.
        • Roohafza H.
        • et al.
        Long-term association of nut consumption and cardiometabolic risk factors.
        Nutr Metabol Cardiovasc Dis. 2019; 29: 972-982
        • Abazarfard Z.
        • Salehi M.
        • Keshavarzi S.
        The effect of almonds on anthropometric measurements and lipid profile in overweight and obese females in a weight reduction program: a randomized controlled clinical trial.
        J Res Med Sci. 2014; 19: 457-464
        • Abbaspour N.
        • Roberts T.
        • Hooshmand S.
        • Kern M.
        • Hong M.Y.
        Mixed nut consumption may improve cardiovascular disease risk factors in overweight and obese adults.
        Nutrients. 2019; 11: 1488
        • Johnston C.S.
        • Trier C.M.
        • Fleming K.R.
        The effect of peanut and grain bar preloads on postmeal satiety, glycemia, and weight loss in healthy individuals: an acute and a chronic randomized intervention trial.
        Nutr J. 2013; 12: 35
        • Iacobini C.
        • Pugliese G.
        • Blasetti Fantauzzi C.
        • Federici M.
        • Menini S.
        Metabolically healthy versus metabolically unhealthy obesity.
        Metabolism. 2019; 92: 51-60
        • Lin H.
        • Zhang L.
        • Zheng R.
        • Zheng Y.
        The prevalence, metabolic risk and effects of lifestyle intervention for metabolically healthy obesity: a systematic review and meta-analysis: a PRISMA-compliant article.
        Medicine (Baltim). 2017; 96: e8838
        • Wildman R.P.
        • Muntner P.
        • Reynolds K.
        • McGinn A.P.
        • Rajpathak S.
        • Wylie-Rosett J.
        • et al.
        The obese without cardiometabolic risk factor clustering and the normal weight with cardiometabolic risk factor clustering: prevalence and correlates of 2 phenotypes among the US population (NHANES 1999-2004).
        Arch Intern Med. 2008; 168: 1617-1624
        • Eckel N.
        • Li Y.
        • Kuxhaus O.
        • Stefan N.
        • Hu F.B.
        • Schulze M.B.
        Transition from metabolic healthy to unhealthy phenotypes and association with cardiovascular disease risk across BMI categories in 90 257 women (the Nurses' Health Study): 30 year follow-up from a prospective cohort study.
        Lancet Diabetes Endocrinol. 2018; 6: 714-724
        • Mongraw-Chaffin M.
        • Foster M.C.
        • Anderson C.A.M.
        • Burke G.L.
        • Haq N.
        • Kalyani R.R.
        • et al.
        Metabolically healthy obesity, transition to metabolic syndrome, and cardiovascular risk.
        J Am Coll Cardiol. 2018; 71: 1857-1865
        • Hosseinpanah F.
        • Tasdighi E.
        • Barzin M.
        • Mahdavi M.
        • Ghanbarian A.
        • Valizadeh M.
        • et al.
        The association between transition from metabolically healthy obesity to metabolic syndrome, and incidence of cardiovascular disease: tehran lipid and glucose study.
        PLoS One. 2020; 15: e0239164
        • Caleyachetty R.
        • Thomas G.N.
        • Toulis K.A.
        • Mohammed N.
        • Gokhale K.M.
        • Balachandran K.
        • et al.
        Metabolically healthy obese and incident cardiovascular disease events among 3.5 million men and women.
        J Am Coll Cardiol. 2017; 70: 1429-1437
        • Hwang L.C.
        • Bai C.H.
        • Sun C.A.
        • Chen C.J.
        Prevalence of metabolically healthy obesity and its impacts on incidences of hypertension, diabetes and the metabolic syndrome in Taiwan.
        Asia Pac J Clin Nutr. 2012; 21: 227-233
        • Stelmach-Mardas M.
        • Walkowiak J.
        Dietary interventions and changes in cardio-metabolic parameters in metabolically healthy obese subjects: a systematic review with meta-analysis.
        Nutrients. 2016; 8: 455
        • Vilela D.L.S.
        • Fonseca P.G.
        • Pinto S.L.
        • Bressan J.
        Influence of dietary patterns on the metabolically healthy obesity phenotype: a systematic review.
        Nutr Metabol Cardiovasc Dis. 2021; 31: 2779-2791
        • Moher D.
        • Liberati A.
        • Tetzlaff J.
        • Altman D.G.
        Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement.
        PLoS Med. 2009; 6e1000097
      1. Higgins J.P.T. Thomas J. Chandler J. Cumpston M. Li T. Page M.J. Welch V.A. Cochrane Handbook for systematic reviews of interventions version 6.3. 2022 (Cochrane)
        • Fernández-Rodríguez R.
        • Mesas A.E.
        • Garrido-Miguel M.
        • Martínez-Ortega I.A.
        • Jiménez-López E.
        • Martínez-Vizcaíno V.
        The relationship of tree nuts and peanuts with adiposity parameters: a systematic review and network meta-analysis.
        Nutrients. 2021; 13
        • Higgins J.
        • Altman D.
        • Sterne J.
        On behalf of the Cochrane statistical methods group and the Cochrane bias methods Group.Chapter 8: assessing risk of bias in included studies.
        in: Higgins J.P.T. Green S. Cochrane Handbook for systematic reviews of interventions version 5.1.0. The Cochrane Collaboration, 2011 (Available from)
        • McKay D.L.
        • Eliasziw M.
        • Chen C.Y.O.
        • Blumberg J.B.
        A pecan-rich diet improves cardiometabolic risk factors in overweight and obese adults: a randomized controlled trial.
        Nutrients. 2018; 10: 339
        • Moreira Alves R.D.
        • Boroni Moreira A.P.
        • Macedo V.S.
        • Bressan J.
        • de Cássia Gonçalves Alfenas R.
        • Mattes R.
        • et al.
        High-oleic peanuts: new perspective to attenuate glucose homeostasis disruption and inflammation related obesity.
        Obesity. 2014; 22: 1981-1988
        • de Souza R.G.M.
        • Gomes A.C.
        • de Castro I.A.
        • Mota J.F.
        A baru almond-enriched diet reduces abdominal adiposity and improves high-density lipoprotein concentrations: a randomized, placebo-controlled trial.
        Nutrition. 2018; 55–56: 154-160
        • Tey S.L.
        • Gray A.R.
        • Chisholm A.W.
        • Delahunty C.M.
        • Brown R.C.
        The dose of hazelnuts influences acceptance and diet quality but not inflammatory markers and body composition in overweight and obese individuals.
        J Nutr. 2013; 143: 1254-1262
        • Foster G.D.
        • Shantz K.L.
        • Vander Veur S.S.
        • Oliver T.L.
        • Lent M.R.
        • Virus A.
        • et al.
        A randomized trial of the effects of an almond-enriched, hypocaloric diet in the treatment of obesity.
        Am J Clin Nutr. 2012; 96: 249-254
        • Li Z.
        • Song R.
        • Nguyen C.
        • Zerlin A.
        • Karp H.
        • Naowamondhol K.
        • et al.
        Pistachio nuts reduce triglycerides and body weight by comparison to refined carbohydrate snack in obese subjects on a 12-week weight loss program.
        J Am Coll Nutr. 2010; 29: 198-203
        • Rock C.L.
        • Zunshine E.
        • Nguyen H.T.
        • Perez A.O.
        • Zoumas C.
        • Pakiz B.
        • et al.
        Effects of pistachio consumption in a behavioral weight loss intervention on weight change, cardiometabolic factors, and dietary intake.
        Nutrients. 2020; 12: 2155
        • Blanco Mejia S.
        • Kendall C.W.
        • Viguiliouk E.
        • Augustin L.S.
        • Ha V.
        • Cozma A.I.
        • et al.
        Effect of tree nuts on metabolic syndrome criteria: a systematic review and meta-analysis of randomised controlled trials.
        BMJ Open. 2014; 4: e004660
        • Del Gobbo L.C.
        • Falk M.C.
        • Feldman R.
        • Lewis K.
        • Mozaffarian D.
        Effects of tree nuts on blood lipids, apolipoproteins, and blood pressure: systematic review, meta-analysis, and dose-response of 61 controlled intervention trials.
        Am J Clin Nutr. 2015; 102: 1347-1356
        • Ros E.
        Health benefits of nut consumption.
        Nutrients. 2010; 2: 652-682
        • DiNicolantonio J.J.
        • O'Keefe J.H.
        Effects of dietary fats on blood lipids: a review of direct comparison trials.
        Open Heart. 2018; 5: e000871
        • Ooi E.M.
        • Watts G.F.
        • Ng T.W.
        • Barrett P.H.
        Effect of dietary Fatty acids on human lipoprotein metabolism: a comprehensive update.
        Nutrients. 2015; 7: 4416-4425
        • Islam S.U.
        • Ahmed M.B.
        • Ahsan H.
        • Lee Y.-S.
        Recent molecular mechanisms and beneficial effects of phytochemicals and plant-based whole foods in reducing LDL-C and preventing cardiovascular disease.
        Antioxidants. 2021; 10: 784
        • Sepandi M.
        • Abbaszadeh S.
        • Qobady S.
        • Taghdir M.
        Effect of L-Arginine supplementation on lipid profiles and inflammatory markers: a systematic review and meta-analysis of randomized controlled trials.
        Pharmacol Res. 2019; 148: 104407
        • Ras R.T.
        • Geleijnse J.M.
        • Trautwein E.A.
        LDL-cholesterol-lowering effect of plant sterols and stanols across different dose ranges: a meta-analysis of randomised controlled studies.
        Br J Nutr. 2014; 112: 214-219
        • St-Onge M.P.
        • Jones P.J.
        Phytosterols and human lipid metabolism: efficacy, safety, and novel foods.
        Lipids. 2003; 38: 367-375
        • Brown R.C.
        • Tey S.L.
        • Gray A.R.
        • Chisholm A.
        • Smith C.
        • Fleming E.
        • et al.
        Nut consumption is associated with better nutrient intakes: results from the 2008/09 New Zealand Adult Nutrition Survey.
        Br J Nutr. 2016; 115: 105-112
        • Dikariyanto V.
        • Berry S.E.
        • Pot G.K.
        • Francis L.
        • Smith L.
        • Hall W.L.
        Tree nut snack consumption is associated with better diet quality and CVD risk in the UK adult population: national Diet and Nutrition Survey (NDNS) 2008-2014.
        Publ Health Nutr. 2020; 23: 3160-3169
        • Pearson K.R.
        • Tey S.L.
        • Gray A.R.
        • Chisholm A.
        • Brown R.C.
        Energy compensation and nutrient displacement following regular consumption of hazelnuts and other energy-dense snack foods in non-obese individuals.
        Eur J Nutr. 2017; 56: 1255-1267
        • Wibisono C.
        • Probst Y.
        • Neale E.
        • Tapsell L.
        Changes in diet quality during a 12 month weight loss randomised controlled trial.
        BMC Nutrition. 2017; 3: 38
        • Capel F.
        • Viguerie N.
        • Vega N.
        • Dejean S.
        • Arner P.
        • Klimcakova E.
        • et al.
        Contribution of energy restriction and macronutrient composition to changes in adipose tissue gene expression during dietary weight-loss programs in obese women.
        J Clin Endocrinol Metab. 2008; 93: 4315-4322
        • Minderis P.
        • Fokin A.
        • Dirmontas M.
        • Kvedaras M.
        • Ratkevicius A.
        Caloric restriction per se rather than dietary macronutrient distribution plays a primary role in metabolic health and body composition improvements in obese mice.
        Nutrients. 2021; 13: 3004
        • Lee-Bravatti M.A.
        • Wang J.
        • Avendano E.E.
        • King L.
        • Johnson E.J.
        • Raman G.
        Almond consumption and risk factors for cardiovascular disease: a systematic review and meta-analysis of randomized controlled trials.
        Adv Nutr. 2019; 10: 1076-1088
        • Li J.
        • Jiang B.
        • Santos H O.
        • Santos D.
        • Singh A.
        • Wang L.
        Effects of walnut intake on blood pressure: a systematic review and meta-analysis of randomized controlled trials.
        Phytother Res. 2020; 34: 2921-2931
        • Yang L.
        • Guo Z.
        • Qi S.
        • Fang T.
        • Zhu H.
        • Santos H.O.
        • et al.
        Walnut intake may increase circulating adiponectin and leptin levels but does not improve glycemic biomarkers: a systematic review and meta-analysis of randomized clinical trials.
        Compl Ther Med. 2020; 52: 102505
        • Jafari Azad B.
        • Daneshzad E.
        • Azadbakht L.
        Peanut and cardiovascular disease risk factors: a systematic review and meta-analysis.
        Crit Rev Food Sci Nutr. 2020; 60: 1123-1140
        • Tindall A.M.
        • Johnston E.A.
        • Kris-Etherton P.M.
        • Petersen K.S.
        The effect of nuts on markers of glycemic control: a systematic review and meta-analysis of randomized controlled trials.
        Am J Clin Nutr. 2019; 109: 297-314
        • Ghanavati M.
        • Rahmani J.
        • Clark C.C.T.
        • Hosseinabadi S.M.
        • Rahimlou M.
        Pistachios and cardiometabolic risk factors: a systematic review and meta-analysis of randomized controlled clinical trials.
        Compl Ther Med. 2020; 52: 102513
        • Nowrouzi-Sohrabi P.
        • Hassanipour S.
        • Sisakht M.
        • Daryabeygi-Khotbehsara R.
        • Savardashtaki A.
        • Fathalipour M.
        The effectiveness of pistachio on glycemic control and insulin sensitivity in patients with type 2 diabetes, prediabetes and metabolic syndrome: a systematic review and meta-analysis.
        Diabetes Metabol Syndr. 2020; 14: 1589-1595
        • Mohammadifard N.
        • Salehi-Abargouei A.
        • Salas-Salvadó J.
        • Guasch-Ferré M.
        • Humphries K.
        • Sarrafzadegan N.
        The effect of tree nut, peanut, and soy nut consumption on blood pressure: a systematic review and meta-analysis of randomized controlled clinical trials.
        Am J Clin Nutr. 2015; 101: 966-982
        • Deeks J.J.
        • Higgins J.P.T.
        • Altman D.G.
        Chapter 10: analysing data and undertaking meta-analyses.
        in: Higgins J.P.T. Thomas J. Chandler J. Cumpston M. Li T. Page M.J. Welch V.A. Cochrane Handbook for systematic reviews of interventions version 6.3. 2022 (Cochrane)
        • Page M.J.
        • Higgins J.P.T.
        • Sterne J.A.C.
        Chapter 13: assessing risk of bias due to missing results in a synthesis.
        in: Higgins J.P.T. Thomas J. Chandler J. Cumpston M. Li T. Page M.J. Welch V.A. Cochrane Handbook for systematic reviews of interventions version 6.3. 2022 (Cochrane)