Walnut ingestion in adults at risk for diabetes: effects on body composition, diet quality, and cardiac risk measures

Abstract

BackgroundDespite their energy density, walnuts can be included in the diet without adverse effects on weight or body composition. The effect of habitual walnut intake on total calorie intake is not well studied. Effects on overall diet quality have not been reported.MethodsRandomized, controlled, modified Latin square parallel design study with 2 treatment arms. The 112 participants were randomly assigned to a diet with or without dietary counseling to adjust calorie intake. Within each treatment arm, participants were further randomized to 1 of the 2 possible sequence permutations to receive a walnut-included diet with 56 g (providing 366 kcal) of walnuts per day and a walnut-excluded diet. Participants were assessed for diet quality, body composition, and cardiac risk measures.ResultsWhen compared with a walnut-excluded diet, a walnut-included diet for 6 months, with or without dietary counseling to adjust caloric intake, significantly improved diet quality as measured by the Healthy Eating Index 2010 (9.14±17.71 vs 0.40±15.13; p=0.02 and 7.02±15.89 vs -5.92±21.84; p=0.001, respectively). Endothelial function, total and low-density lipoprotein (LDL) cholesterol improved significantly from baseline in the walnut-included diet. Body mass index, percent body fat, visceral fat, fasting glucose, glycated hemoglobin, and blood pressure did not change significantly.ConclusionsThe inclusion of walnuts in an ad libitum diet for 6 months, with or without dietary counseling to adjust calorie intake, significantly improved diet quality, endothelial function, total and LDL cholesterol, but had no effects on anthropometric measures, blood glucose level, and blood pressure.Trial registration number:NCT02330848

Changes in diet quality during a 12 month weight loss randomised controlled trial

“…Regardless of the index used the high diet quality scores for IW is consistent with studies when walnuts and nuts more generally were provided in controlled portions [69][70][71][72][73][74]. It has been suggested that providing nuts may improve diet quality by displacing consumption of other less nutritious foods [70].…”

“…The consumption of walnuts (and other nuts) is associated with cardio-protective effects [78,79] including improving serum lipid profiles [80] without promoting weight gain [81]. Providing these foods in trial settings may support adherence towards dietary interventions [69][70][71][72][73][74] provided quantities for consumption were deemed acceptable [72]. At least in the trial setting, providing a healthy food supplement, such as walnuts, in trials appears to lead to superior adherence and improvements in diet quality outcomes.…”

Association of Adherence to Specific Mediterranean Diet Components and Cardiorespiratory Fitness in Young Adults

“…(2) Consumption of 4 or more tablespoons (1 tablespoon = 13.5 g) of olive oil/day; (3) Consumption of 2 or more servings (1 serving = 200 g) of vegetables/day; (4) Consumption of 3 or more pieces of fruit/day; (5) Consumption of less than 1 serving (1 serving = 100 g) of red meat or hamburger or sausages/day; (6) Consumption of less than 1 serving (12 g) of animal fat, such as butter, margarine, or cream/day; (7) Consumption of less than 1 glass (100 mL) of sugar-sweetened beverages/day; (8) Consumption of 7 or more glasses (100 mL) of red wine/week; (9) Consumption of 3 or more servings (1 serving = 150 g) of pulses/week; (10) Consumption of 3 or more servings (1 serving = 150 g) of fish/week; (11) Consumption of less than two commercial pastries/week; (12) Consumption of 3 or more servings (1 serving = 30 g) of tree nuts/week; (13) Preferring white meat over red meat; (14) Consumption of "sofrito" (a sauce made with tomato, onion, garlic or leek simmered with olive oil) 2 or more times/week. DIAL program (Alce Ingenieria Madrid, Spain 2008) was used for the 24 h questionnaire assessment.…”

The Effect of Walnut Oil Consumption on Blood Sugar in Patients With Diabetes Mellitus Type 2

“…Increase in consumption of nuts was reported to reduce the risk of CAD development and mortality caused by CAD (16, 17). The risks for progression of DM type 2 and health threatening conditions were reduced by consumption of nuts such as walnut (18). In this regard, because of the lower mortality caused by CAD and cancers in the Mediterranean population, the Mediterranean diet is still considered a favorable choice (19).…”