Abstract
Objectives
To examine the effect of consuming one ounce of peanuts (PNUT) as an evening snack on fasting plasma glucose and other cardiovascular disease risk factors, compared to an isocaloric lower fat higher carbohydrate snack (LFHC), in individuals with IFG.
Methods
Fifty-one individuals with IFG (52% male; 42 ± 15 y; BMI 28 ± 5.6 kg/m2; glucose 105 ± 4.9 mg/dL) were enrolled in this two-period, randomized, crossover trial. In random order, subjects consumed each snack in the evening (after dinner and before bedtime) for 6 weeks (PNUT: 164 kcal, 14 g fat, 2.2 g saturated fat, 6 g carbohydrate, 7 g protein, 2.4 g fiber; LFHC: 165 kcal, 6 g fat, 2 g saturated fat, 22 g carbohydrate, 7 g protein, 3.0 g fiber). Subjects were told not to consume other caloric foods/beverages after dinner. On two consecutive days at the beginning and end of each diet period a fasting blood sample was assessed for plasma glucose, serum lipids/lipoproteins, and insulin. Blood pressure (BP) and pulse wave velocity (PWV) were measured at each time point.
Results
Compared with baseline (100 mg/dL, 95% CI 99, 102), glucose was unchanged following both conditions (PNUT: −0.9 mg/dL 95% CI −2.1, 1.3; LFHC: −0.4 mg/dL 95% CI −2.6, 0.8) with no between-condition difference (P > 0.05). Changes for LDL-C from baseline differed between conditions (−4.8 mg/dL; 95% CI −9.2, −0.4); there were no within-condition changes from baseline (LFHC −2.3 mg/dL, 95% CI −5.7, 1.0; PNUT 2.5 mg/dL, 95% CI −0.9, 5.8). Greater triglyceride lowering was observed with PNUT (−17 mg/dL, 95% CI −28, −6.2) vs. LFHC (−5.7 mg/dL, 95% CI −17, 5.1). There were no condition effects for weight, HDL-C, insulin, BP or PWV. In a post hoc analysis of subjects who had IFG (>99 mg/dL) at baseline (107 mg/dL, 95% CI 106, 108), glucose was lowered compared to baseline for both conditions (PNUT: −2.6 mg/dL, 95% CI −4.6, −0.6; LFHC: −3.1 mg/dL, 95% CI −5.1, −1.0).
Conclusions
In individuals with IFG, consuming a relatively low-calorie, mixed macronutrient, nighttime snack improves fasting glucose levels. Greater reductions in triglycerides were observed with evening peanut consumption, which may be explained by the lower carbohydrate and higher fat content.
Funding Sources
The Peanut Institute Supported by the National Center for Advancing Translational Sciences, National Institutes of Health.