Whole Soy Replacement Diet on Metabolic Features

A Randomized Controlled Trial of Whole Soy Diet in Place of Red/Processed Meat and High Fat Dairy Products on Metabolic Features in Postmenopausal Women

Project title: A randomized controlled trial of whole soy diet in place of red/processed meat and high fat dairy products on metabolic features in postmenopausal women Objectives: Metabolic syndrome (MetS) is an escalating public health problem especially in postmenopausal women. Traditional whole soy foods are rich in unsaturated fats, high quality plant protein and various bioactive phytochemicals that could benefit on MetS. The aim of the study is to examine the effect of whole soy replacement diet on the features of MetS among postmenopausal women. Hypothesis to be tested: Whole soy diet in place of red or processed meat and high fat dairy products will significantly improve metabolic features. Design and subjects: This will be a 12-month randomized, single-blind, controlled trial among 208 postmenopausal women with high risk of MetS or early MetS. Study instruments: After 4 weeks' run-in, participants will be randomly allocated to either of two intervention groups, whole soy replacement group or control group, each for 6 months. Interventions: Subjects in whole soy group will be required to include 4 servings of whole soy foods (containing 25g soy protein) into their daily diet isocalorically replacing red or processed meat and high fat dairy products. Subjects in the control group will remain an usual diet. Main outcome measures: The outcome measures will include the indices of metabolic features as well as a 10-year risk for ischemic cardiovascular disease. Data analysis: The changes and %change of the metabolic features at 6- and 12-month will be compared among the two groups. Expected results: Whole soy diet substitution of high saturated fat and cholesterol rich animal products will notably decrease the risk of MetS.

Whole soy replacement diet: to incorporate 4 servings of whole soy foods (equivalent to 25g soy protein) into their daily diet and reduce high saturated fat and cholesterol rich animal foods.

Participants who are allocated to Whole soy group will receive a 30~40 min counseling session by an experienced nutritionist on: 1) conventional lifestyle education on metabolic syndrome (MetS); 2) The benefits of whole soy diet; 2) Practical techniques to incorporate of 4 servings of whole soy foods (equivalent to 25g soy protein) into their daily diet and reduce high saturated fat and cholesterol rich animal foods based on their prior 7-day dietary record during run-in; (3) Participants will also receive a pamphlet and an 30 min DVD which will provide practical cooking recipes with both illustration and demonstration on how to prepare whole soy foods/diet in an easy and fun way to replace fatty animal meat and dairy products

Participants who are assigned to the usual diet group (control group) will receive a 5~10 min conventional lifestyle education on MetS by a research staff in which the general recommendation for macronutrient composition of the control diet will be 50-60% of energy as carbohydrate, 15-20% of energy as protein, and <30% of energy as total fat.

Changes of metabolic components of MetS (body weight, waist circumference, blood pressure, serum lipids and fasting glucose).

Inclusion Criteria: Postmenopausal women aged 45~70y within 15 years after menopause; Participants who meet 2 or more of the following items: waist circumference WC ≥80 cm; triglyceride concentration ≥1.7 mmol/l; HDL-c <50 mg/dl (1.29 mmol/l); SBP/DBP ≥130/85 mm Hg; fasting glucose ≥5.6 mmol/l. Exclusion Criteria: On use of medications known to affect body weight, lipids and glucose within past 3-month; Medical history or presence of severe systemic or endocrine diseases; Present or history of breast, endometrial or ovarian cancer; Abnormal uterine bleeding after menopause; On prescribed or vegetarian diet; Known soy allergy.

Liu ZM, Ho S, Hao YT, Chen YM, Woo J, Wong SY, He Q, Xie YJ, Tse LA, Chen B, Su XF, Lao XQ, Wong C, Chan R, Ling WH. Randomised controlled trial of effect of whole soy replacement diet on features of metabolic syndrome in postmenopausal women: study protocol. BMJ Open. 2016 Sep 27;6(9):e012741. doi: 10.1136/bmjopen-2016-012741.