Scientific Study

OBJECTIVE: To evaluate the effect of an almond-enriched (high monounsaturated fat; MUFA) or complex carbohydrate-enriched (high carbohydrate) formula-based low-calorie diet (LCD) on anthropometric; body composition and metabolic parameters in a weight reduction program. DESIGN: A randomized; prospective 24-week trial in a free-living population evaluating two distinct macronutrient interventions on obesity and metabolic syndrome-related parameters during weight reduction. SUBJECTS: In total; 65 overweight and obese adults (age: 27-79 y; body mass index (BMI): 27-55 kg/m(2)). INTERVENTION: A formula-based LCD enriched with 84 g/day of almonds (almond-LCD; 39% total fat; 25% MUFA and 32% carbohydrate as percent of dietary energy) or self-selected complex carbohydrates (CHO-LCD; 18% total fat; 5% MUFA and 53% carbohydrate as percent of dietary energy) featuring equivalent calories and protein. MAIN OUTCOME MEASUREMENTS: Various anthropometric; body composition and metabolic parameters at baseline; during and after 24 weeks of dietary intervention. RESULTS: LCD supplementation with almonds; in contrast to complex carbohydrates; was associated with greater reductions in weight/BMI (-18 vs -11%); waist circumference (WC) (-14 vs -9%); fat mass (FM) (-30 vs -20%); total body water (-8 vs -1%) and systolic blood pressure (-11 vs 0%); P=0.0001-0.05. A 62% greater reduction in weight/BMI; 50% greater reduction in WC and 56% greater reduction in FM were observed in the almond-LCD as compared to the CHO-LCD intervention. Ketone levels increased only in the almond-LCD group (+260 vs 0%; P<0.02). High-density lipoprotein cholesterol (HDL-C) increased in the CHO-LCD group and decreased in the almond-LCD group (+15 vs -6%; P=0.05). Glucose; insulin; diastolic blood pressure; total cholesterol; triglycerides; low-density lipoprotein cholesterol (LDL-C) and LDL-C to HDL-C ratio decreased significantly to a similar extent in both dietary interventions. Homeostasis model analysis of insulin resistance (HOMA-IR) decreased in both study groups over time (almond-LCD: -66% and CHO-LCD: -35%; P<0.0001). Among subjects with type 2 diabetes; diabetes medication reductions were sustained or further reduced in a greater proportion of almond-LCD as compared to CHO-LCD subjects (96 vs 50%; respectively) [correction]. CONCLUSION: Our findings suggest that an almond-enriched LCD improves a preponderance of the abnormalities associated with the metabolic syndrome. Both dietary interventions were effective in decreasing body weight beyond the weight loss observed during long-term pharmacological interventions; however; the almond-LCD group experienced a sustained and greater weight reduction for the duration of the 24-week intervention. Almond supplementation of a formula-based LCD is a novel alternative to self-selected complex carbohydrates and has a potential role in reducing the public health implications of obesity.