Legume Diet Satiety Pilot Study

This pilot study is designed to test the effects of a high legume (dried bean) diet on hunger and other indicators of health over the course of eight weeks, compared to a more conventional healthy diet.

The goal of the currently proposed study is to conduct a randomized controlled feeding pilot study within a more diverse population also at high risk for colorectal carcinoma (CRC) to evaluate whether a high-legume diet will result in increased satiety and in turn will facilitate reduced energy intake and weight loss compared to a control diet provided under similar conditions. In addition, explore potential beneficial effects of the high-legume diet on gastric emptying and circulating levels of appetite-regulating hormones and other biomarkers. Dietary behaviors that are even moderately more satiating over time have the potential to enhance weight loss and could lead to a significant public health impact among populations at high risk for colorectal carcinoma (CRC) and other chronic diseases. Towards the end of the study, the participants will do an additional test, looking at how long food takes to pass through the digestive system using a SmartPill capsule. The SmartPill is a pill about the size of a large multivitamin that can measure pH, pressure, and temperature changes, which it uses to assess where in the digestive tract it is. The participant swallows the pill, and carries around a receiver that is about the size of a deck of cards for the next 3-5 days. The SmartPill is expelled, and the receiver notifies the participant that they can return the receiver to the study personnel.

Meals will include approximately 1 ½ cups of cooked legumes, such as pinto, baked and navy beans as part of your 2 daily main dishes (lunch and dinner) and additional foods and snacks, preferably from the recommended healthy foods list. The smartpill will be administered at the end of the study.

Meals will be healthy, typical American foods (without legumes) for 2 daily main dishes and additional foods and snacks, preferably from the recommended healthy foods list.The smartpill will be administered at the end of the study.

Evaluate the effects of a high-legume diet compared to a control diet with a similar macronutrient profile on weight change in a randomized controlled feeding study.

Compare the effects of the high-legume and control diets on plasma insulin level in a meal response time (30 min) course experiment.

Compare the effects of the high-legume and control diets on self-reported dietary intake measured by telephone 24-hour dietary recalls.

Inclusion Criteria: BMI overweight-obese: 25.0-40 kg/m2 Colonoscopy within the last two years that found ≥1 adenoma English speaking Ambulatory, able to come to either food distribution site to pick up food and participate in clinical examinations and laboratory tests Exclusion Criteria: Serious medical condition (e.g., cancer, heart disease, kidney disease, diabetes) History of CRC, bowel resection, polyposis syndrome, or inflammatory bowel disease Smoked regularly in the past year Dietary restrictions substantially limiting compliance or vegetarian or Vegan diet Planning on changing diet or exercise behavior in the next 6 months Regular use of medication that may alter inflammation markers, insulin, glucose, or gut function (i.e. regular use of non-steroidal anti-inflammatory medication, insulin therapy, steroid therapy, or antibiotics)