Lentils as a Functional Food to Improve Glucose and Decrease Cardiovascular Risk (LEN-0-2012)

Compared to control foods, consumption of 3 cups of cooked lentils given weekly for 12 weeks will significantly improve glucose tolerance and lower LDL-cholesterol in individuals with high cholesterol and obesity.

This is a multi-site, randomized, controlled, parallel group food study designed to examine the health benefits, specifically glucose tolerance, insulin sensitivity and LDL-cholesterol in overweight individuals with a high waist circumference and elevated LDL-cholesterol. Recruitment will consist of approximately 102 overweight participants (n= 51 participants per site, at 2 sites located in Winnipeg and Toronto) with high waist circumference and elevated LDL-cholesterol.

• Obesity
• Hypercholesterolemia

• Other: Consumption of cooked lentils
  Consumption of food items containing one serving of (0.3 cups) of cooked lentils per day for the first 5 days, followed by one serving of (0.6 cups) of cooked lentils per day 5 times per week (equivalent of 3 cups cooked lentils per week) for the remainder of the 12-week schedule. The foods will be incorporated into the participant's normal dietary pattern.
• Other: Consumption of potato-based foods
  Consumption one serving per day of potato-based foods in matrices similar to those containing lentils in the same 12-week schedule, including the smaller serving size for the first 5 days. The foods will be incorporated into the participant's normal dietary pattern.

• Experimental: Consumption of cooked lentils
  Intervention: Other: Consumption of cooked lentils
• Active Comparator: Consumption of potato-based foods
  Intervention: Other: Consumption of potato-based foods

• Abdul-Ghani MA, Matsuda M, Balas B, DeFronzo RA. Muscle and liver insulin resistance indexes derived from the oral glucose tolerance test. Diabetes Care. 2007 Jan;30(1):89-94.
• Phillips DI, Clark PM, Hales CN, Osmond C. Understanding oral glucose tolerance: comparison of glucose or insulin measurements during the oral glucose tolerance test with specific measurements of insulin resistance and insulin secretion. Diabet Med. 1994 Apr;11(3):286-92.
• American Heart Association Nutrition Committee, Lichtenstein AH, Appel LJ, Brands M et al. (2006). Circulation 114: 82-96.

Inclusion Criteria:

• Male or non-pregnant, non-lactating females aged 30 to 75 years;
• Body Mass Index of ≤40 kg/m2 and ≥23 kg/m2 if Asian or ≥25 kg/m2 if non-Asian;
• Waist circumference ≥94 cm for males and ≥80 cm for females of Asian ethnicity,and ≥102 cm for males and ≥88 cm of non-Asian ethnicity;
• Fasting plasma glucose <7 mmol/L;
• Fasting triglycerides <4.00 mmol/L and LDL-cholesterol >2.50 mmol/L and <5.00 mmol/L;
• Must be on a stable regime for the past 3 months if taking medications to treat hypertension or if taking vitamin and mineral/dietary/herbal supplements;
• Stable body weight (±3 kg) for the past 3 months

Exclusion Criteria:

• Previous diagnosis of type 2 diabetes;
• High pulse consumption (≥2 servings per week);
• Presence of liver disease (aspartate transaminase >2 times Upper Normal Limit), renal insufficiency (creatinine >1.5 times Upper Normal Limit); inflammatory bowel disease or other gastrointestinal disorders influencing gastrointestinal motility or nutrient absorption;
• Use of medication which influence carbohydrate metabolism (i.e., steroids), or medications used to treat diabetes or to lower blood lipids, or any active medical or surgical conditions within the past 3 months;
• Conditions or medications which are likely to increase the risk to the participants or study personnel, or to reduce the ability of the participant to comply with the protocol, or affect the results;
• History of gastrointestinal reactions or allergies to lentils or potato-based foods, or to one or more ingredients in the study foods which significantly limits the number of study foods that can be consumed.