title: Does regular walnut consumption lead to weight gain?
abstract: Studies consistently show the beneficial effects of eating nuts, but as high-energy foods, their regular consumption may lead to weight gain. We tested if daily consumption of walnuts (approximately 12 % energy intake) for 6 months would modify body weight and body composition in free-living subjects. Ninety participants in a 12-month randomized cross-over trial were instructed to eat an allotted amount of walnuts (28-56 g) during the walnut-supplemented diet and not to eat them during the control diet, with no further instruction. Subjects were unaware that body weight was the main outcome. Dietary compliance was about 95 % and mean daily walnut consumption was 35 g during the walnut-supplemented diet. The walnut-supplemented diet resulted in greater daily energy intake (557 kJ (133 kcal)), which should theoretically have led to a weight gain of 3.1 kg over the 6-month period. For all participants, walnut supplementation increased weight (0.4 (se 0.1) kg), BMI (0.2 (se 0.1) kg/m(2)), fat mass (0.2 (se 0.1) kg) and lean mass (0.2 (se 0.1) kg). But, after adjusting for energy differences between the control and walnut-supplemented diets, no significant differences were observed in body weight or body composition parameters, except for BMI (0.1 (se 0.1) kg/m(2)). The weight gain from incorporating walnuts into the diet (control-->walnut sequence) was less than the weight loss from withdrawing walnuts from the diet (walnut-->control sequence). Our findings show that regular walnut intake resulted in weight gain much lower than expected and which became non-significant after controlling for differences in energy intake.
authors.affiliation: Department of Nutrition, School of Public Health, Loma Linda University, Loma Linda, CA 92350, USA. jsabate@llu.edu
authors.forename: Joan
authors.initials: J
authors.lastname: Sabaté
authors.forename: Zaida
authors.initials: Z
authors.lastname: Cordero-Macintyre
authors.forename: Gina
authors.initials: G
authors.lastname: Siapco
authors.forename: Setareh
authors.initials: S
authors.lastname: Torabian
authors.forename: Ella
authors.initials: E
authors.lastname: Haddad
mesh_terms: D000273:Adipose Tissue / Q000502:physiology; D000328:Adult; D000368:Aged; D001823:Body Composition / Q000502:physiology; D015992:Body Mass Index; D018592:Cross-Over Studies; D019587:Dietary Supplements; D002149:Energy Intake / Q000502:physiology; D004910:Erythrocyte Membrane / Q000378:metabolism; D015444:Exercise / Q000502:physiology; D005260:Female; D006801:Humans; D031324:Juglans; D008297:Male; D008875:Middle Aged; D010349:Patient Compliance; D015430:Weight Gain / Q000502:physiology*; D017962:alpha-Linolenic Acid / Q000097:blood
chemical_list: D017962:alpha-Linolenic Acid