The specific aim of this study is to determine the effects of substituting brown for white rice on the treatment of metabolic syndrome (MetS).

Metabolic syndrome (MetS), a constellation of metabolic abnormalities including central obesity, dyslipidemia, elevated blood pressure and hyperglycemia, is associated with the development of type 2 diabetes and CVD. It has become one of the major public health challenges in China due to rapidly nutrition transition and the nature of obesity epidemic. Treatment of MetS in China is very important for the prevention of the epidemic of its consequences (such as CVD and type 2 diabetes).

Compelling evidence from recent human studies has demonstrated that diet modifications are effective means in MetS management. Consumption of carbohydrate-rich foods such as rice affects blood glucose and influences diabetes risk. Specifically, eating polished white rice may increase diabetes risk, whereas eating brown rice, a whole grain product, may decrease risk. This is likely related to the different ability of white and brown rice to raise blood glucose levels, as measured by their glycemic index (GI) and glycemic load (GL), and to the higher levels of dietary fiber, vitamin B complex, magnesium and other micronutrients in brown rice.

A total of 200 participants with MetS (defined by ATP-III criteria) will be randomly assigned to a brown rice diet or an isocaloric white rice diet for 16 weeks. Effects of substituting brown for white rice will be evaluated by measuring metabolic profile (BMI, blood pressure, total cholesterol, triglyceride, LDL-C and HDL-C, fasting glucose and insulin, HbA1C).

Inclusion Criteria:

• The updated National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria for the diagnosis of the MetS will be used. MetS will be defined with at least three of the following abnormalities:

  • central obesity (defined as waist circumference ≥ 80 cm for women or ≥ 90 cm for men)
  • Raised triglycerides level: ≥ 150 mg/dL (1.7 mmol/L), or specific treatment for this lipid abnormality;
  • Reduced HDL cholesterol: < 40 mg/dL (1.0 mmol/L) in males and < 50 mg/dL (1.3 mmol/L) in females, or specific treatment for this lipid abnormality;
  • Elevated blood pressure (BP): systolic BP ≥ 130 or diastolic BP ≥ 85 mm Hg, or treatment of previously diagnosed hypertension;
  • Increased fasting plasma glucose (FPG): ≥ 100 mg/dL (5.6 mmol/L), or previously diagnosed type 2 diabetes.

• Being able to comply with the specified feeding conditions

• Being able to eat brown rice

• Being between the ages of 35 and 60 years

Exclusion Criteria:

• Pregnancy or lactation
• Use of insulin
• Severe kidney disease
• Cardiovascular diseases, stroke, cancer and psychological disorders
• Brown rice allergies
• Drug or alcohol abuse