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. 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. In total, 65 overweight and obese adults (age: 27-79 y, body mass index (BMI): 27-55 kg/m(2)). 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. Various anthropometric, body composition and metabolic parameters at baseline, during and after 24 weeks of dietary intervention. 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]. 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.
