Use of a Soy-based Meal Replacement Weight Loss Intervention to Impact Ectopic Fat
Condition: Abdominal Obesity
MeSH terms: Cardiac Complexes, Premature; Obesity, Abdominal; Weight Loss
Study type: Interventional

Summary: 
      The main objectives of this study are to collect pilot data to assess feasibility (accrual,
      retention, compliance), to estimate the variability of outcome measures, and to obtain
      preliminary estimates of treatment efficacy based on group differences in body composition
      (decreases in ectopic fat stores while maintaining lean mass), cardio-metabolic risk factors
      including glucoregulatory function (glucose, insulin), inflammation (C-reactive protein,
      IL-6), blood pressure and lipids (HDL, LDL, TC, TG), and measures of physical function and
      muscle strength. While this is just a pilot study, randomization will be used so that the
      investigators can obtain a realistic estimate of accrual (which is often less in a randomized
      trial) and an unbiased estimate of treatment efficacy.

      The investigators will accomplish these objectives by conducting a 2-arm, 3-month randomized,
      clinical trial in 24 older (60-79), abdominally obese (BMI ≥30 kg/m2 and waist circumference
      ≥ 102 cm and ≥ 88 cm in men and women, respectively) men and women. Participants will be
      randomized to a soy-based or animal-based, 3-month, hypocaloric dietary intervention to
      achieve our specific aims:

      Primary Aim: To determine our ability to recruit and retain older, obese adults to a 3 month
      soy-based meal replacement weight loss intervention and assess the study participant's
      ability to adhere to the intervention protocol (weight, compliance logs, serum isoflavones).

      Secondary Aims:

        1. To estimate the variability of and obtain preliminary estimates of the effect of the
           soy-based meal replacement on measures of body composition, including abdominal (total,
           subcutaneous and visceral fat), liver, and pericardial fat; anthropometrics (body
           weight, waist/hip circumference); and whole body fat and lean mass.

        2. To estimate the variability of and obtain preliminary estimates of the effect of the
           soy-based meal replacement on biomarkers of cardiometabolic risk including
           glucoregulatory function (glucose, insulin), inflammation (C-reactive protein, IL-6),
           blood pressure and lipids (HDL, LDL, TC, TG).

        3. To estimate the variability of and obtain preliminary estimates of the effect of the
           soy-based meal replacement on physical function (short physical performance battery,
           400-m walk) and muscle strength (grip and knee extensor strength) and size (CT thigh
           muscle).

        4. To document any adverse events associated with the soy-based meal replacement.
    


Intervention name(s): Medifast meal replacement products; Medifast meal replacement products
Intervention type(s): Dietary Supplement; Dietary Supplement
Intervention description(s): A total of 4 meal replacement (MR)products per participant per day will be used. Approximately 2/3rd of the Medifast® MR product line is soy protein-based (i.e. at least 7 g of total protein coming from soy) with the remaining 1/3rd of items deriving total protein content from animal sources (whey and egg). The soy used in Medifast products is Solae SUPRO® water-washed soy protein isolate. Depending on seasonal variations, soy MR products contain approximately 1.5-3.0 milligrams of soy isoflavones for every 1 gram of soy protein. Thus, participants in the soy treatment arm will consume at least 28 g/soy protein and 42-108 mg/isoflavones per day.; A total of 4 meal replacement (MR)products per participant per day will be used. Approximately 2/3rd of the Medifast® MR product line is soy protein-based (i.e. at least 7 g of total protein coming from soy) with the remaining 1/3rd of items deriving total protein content from animal sources (whey and egg). This group will receive the non soy supplements.
Other intervention name(s): Soy; whey
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Investigator)
Primary purpose: Prevention
Keywords: Obesity; Aging; Soy; Weight Loss; Ectopic Fat