Nut intake and adiposity: meta-analysis of clinical trials.

Unitat de Suport a la Recerca Tarragona-Reus, Institut Universitari d'Investigació en Atenció Primària Jordi Gol, Tarragona, Spain.
American Journal of Clinical Nutrition (Impact Factor: 6.5). 04/2013; 97(6). DOI: 10.3945/ajcn.111.031484
Source: PubMed

ABSTRACT BACKGROUND: Epidemiologic studies have shown an inverse association between the frequency of nut consumption and body mass index (BMI) and risk of obesity. However, clinical trials that evaluated nut consumption on adiposity have been scarce and inconclusive. OBJECTIVE: We performed a systematic review and meta-analysis of published, randomized nut-feeding trials to estimate the effect of nut consumption on adiposity measures. DESIGN: MEDLINE and the Cochrane Central Register of Controlled Trials databases were searched for relevant clinical trials of nut intake that provided outcomes of body weight, BMI (in kg/m(2)), or waist-circumference measures and were published before December 2012. There were no language restrictions. Two investigators independently selected and reviewed eligible studies. The weighted mean difference (WMD) between nut or control diets was estimated by using a random-effects meta-analysis with 95% CIs. RESULTS: Thirty-one clinical trials met our inclusion criteria. Pooled results indicated a nonsignificant effect on body weight (WMD: -0.64 kg; 95% CI: -2.32, 1.05 kg; I(2) = 99%), BMI (WMD: -0.30; 95% CI: -0.92, 0.32; I(2) = 98%), or waist circumference (WMD: -1.10 cm; 95% CI: -3.34, 1.14 cm; I(2) = 96%) of diets including nuts compared with control diets. These findings were remarkably robust in the sensitivity analysis. No publication bias was shown. CONCLUSION: Compared with control diets, diets enriched with nuts did not increase body weight, body mass index, or waist circumference in controlled clinical trials.

  • [Show abstract] [Hide abstract]
    ABSTRACT: The past few decades have witnessed a rapid rise in nutrition-related disorders such as obesity in the United States and over the world. Traditional nutrition research has associated various foods and nutrients with obesity. Recent advances in genomics have led to identification of the genetic variants determining body weight and related dietary factors such as intakes of energy and macronutrients. In addition, compelling evidence has lent support to interactions between genetic variations and dietary factors in relation to obesity and weight change. Moreover, recently emerging data from other 'omics' studies such as epigenomics and metabolomics suggest that more complex interplays between the global features of human body and dietary factors may exist at multiple tiers in affecting individuals' susceptibility to obesity; and a concept of 'personalized nutrition' has been proposed to integrate this novel knowledge with traditional nutrition research, with the hope ultimately to endorse person-centric diet intervention to mitigate obesity and related disorders.
    Annals of Medicine 04/2014; 46(5). · 4.73 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Nuts are rich in many bioactive compounds that can exert beneficial effects on cardiovascular health. We reviewed the evidence relating nut consumption and the metabolic syndrome (MetS) and its components. Nuts reduce the postprandial glycemic response; however, long-term trials of nuts on insulin resistance and glycemic control in diabetic individuals are inconsistent. Epidemiologic studies have shown that nuts may lower the risk of diabetes incidence in women. Few studies have assessed the association between nuts and abdominal obesity, although an inverse association with body mass index and general obesity has been observed. Limited evidence suggests that nuts have a protective effect on blood pressure and endothelial function. Nuts have a cholesterol-lowering effect, but the relation between nuts and hypertriglyceridemia and high-density lipoprotein cholesterol is not well established. A recent pooled analysis of clinical trials showed that nuts are inversely related to triglyceride concentrations only in subjects with hypertriglyceridemia. An inverse association was found between the frequency of nut consumption and the prevalence and the incidence of MetS. Several trials evaluated the effect of nuts on subjects with MetS and found that they may have benefits in some components. Compared with a low-fat diet, a Mediterranean diet enriched with nuts could be beneficial for MetS management. The protective effects on metabolism could be explained by the modulation of inflammation and oxidation. Further trials are needed to clarify the role of nuts in MetS prevention and treatment.
    American Journal of Clinical Nutrition 06/2014; 100(Supplement_1). · 6.92 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Snack foods can contribute a high proportion of energy intake to the diet. Peanuts are a snack food rich in unsaturated fatty acids, protein and fibre which have demonstrated satiety effects and may reduce total energy intake, despite their high energy density. This study examined the effects of consuming Hi-oleic (oleic acid ~75% of total fatty acids) peanuts and regular peanuts (oleic acid ~ 50% and higher in polyunsaturated fatty acids) compared with a high carbohydrate snack (potato crisps) on satiety and subsequent energy intake. Using a triple crossover study design, 24 participants (61±1 years) consumed iso-energetic amounts (56-84g) of Hi-oleic or regular peanuts or (60-90g) potato crisps after an overnight fast. Hunger and satiety were assessed at baseline, 30, 60, 120 and 180 minutes following snack consumption using visual analogue scales, after which a cold buffet meal was freely consumed and energy intake measured. The same snack was consumed on 3 subsequent days with energy intake assessed from dietary records. This protocol was repeated weekly with each snack food. Total energy intake was lower following consumption of Hi-oleic and regular peanuts compared with crisps, both acutely during the buffet meal (-21%; p < .001 and -17%; p < .01) and over the 4 days (-11%; p < .001 and -9%; p < .01). Despite these reductions in energy intake, no differences in perceived satiety were observed. The findings suggest peanuts may be a preferred snack food to include in the diet for maintaining a healthy weight.
    Appetite 07/2014; · 2.52 Impact Factor


Available from
Sep 30, 2014