Controlling diet in a clinical trial of the effects of barley beta glucan on glucose metabolism and insulin sensitivity in subjects at high risk for type 2 diabetes

We used the Therapeutic Lifestyle Changes (TLC) diet to counsel subjects in a clinical trial designed to assess the impact of a flavored, water beverage containing barley β‐glucan (barley betafiber; Barliv TM ) on glucose levels and insulin sensitivity. The beverage was consumed three times a day for 12 weeks, providing 0 grams, 3 grams or 6 grams of β‐glucan per day. Adherence to the TLC diet was assessed using 3‐day food records at baseline, 3, 6, 9 and 12 weeks of the trial. Dietary intake data was analyzed using the Nutrient Data System for Research software. Subjects had improvements in glucose levels and insulin sensitivity during this trial while they maintained their weight (as required) during the trial by following the TLC diet. P‐values for comparisons of macronutrient intake among and between randomization groups and within randomization groups from baseline to 12 weeks were not significant (> 0.05). Parameter [mean(SD)] 0 g/d BBG (n=13) 3 g/d BBG (n=11) 6 g/day BBG (n=14) Body Weight (kg) 92.3 (12.2) 90.9 (14.4) 90.7 (12.9) BMI (kg/m 2 ) 32.1 (3.7) 32.2 (4.5) 32.2 (4.9) Energy (kcal) 1687 (383) 1720 (322) 1513 (319) Fat (g) 61 (18) 68 (22) 58 (20) Fat (% energy) 31 (7) 34 (7) 33 (8) Carbohydrate (g) 199 (63) 195 (26) 175 (67) Carbohydrate (% energy) 46 (7) 45 (9) 44 (10) Protein (g) 83 (23) 75 (26) 75 (16) Protein (% energy) 21 (7) 18 (4) 21 (4) Fiber (g) 19 (7) 18 (7) 20 (12) This trial demonstrates the application of the TLC diet and analysis of dietary intake data to a clinical trial setting in which weight maintenance and stability of the diet is preferred in order to isolate the effects of a nutritive test article.