Effects of native banana starch on body weight and insulin resistance.

INTERVENTION: Forty obese women were selected and divided in two groups in a 2‐arm parallel trial. Participants were randomly assigned to receive either 30 g of native banana starch (NBS) by day dissolved in 240 ml of water or metformin 850 mg/day. Each subject attended the laboratory on three occasions, once before any intervention, again following 4 weeks of intervention and the last at the end of the experimentation after 8 weeks of treatments. An oral glucose tolerance test (OGTT) was carried out before any intervention and after 8 weeks of experimentation. After 12 h fasting a 75g OGTT was performed according to the World Health Organization (WHO) criteria. Blood samples were taken at 0, 30, 60, 90 and 120 min after oral glucose for measuring glucose and insulin. CONDITION: Obesity PRIMARY OUTCOME: Body weight measured by a Tanita BF‐350 body composition analyzer. Insulin resistance estimated according to the Homeostasis Model Assessment (HOMA). SECONDARY OUTCOME: Glucose tolerance as evaluated by an oral glucose tolerance test (OGTT). After a 10‐12‐h overnight fast, a catheter is inserted into an antecubital vein for blood sampling. Baseline samples are obtained and a glucose drink (75 g) is administered. Glucose and insulin are determined at 0,30,60,90 and 120 min after oral glucose. Markers of nutritional status such as height, abdominal circumference and body fat percentage (measured by impedance). Other metabolic responses as assessed through blood concentration changes of cholesterol, tryglycerides, Magnesium, aspartate amino transferase (AST)and alanin aminotransferase (ALT). INCLUSION CRITERIA: 1. Female 2. Body Mass Index (BMI) >30 3.HOMA‐Index > 2.5 4. Fast glycemia under 126 mg/dL 5. 2 h postprandial glycemia under 200 mg/dl 6. Have mantained stable weight during three months prior to experimentation 7. To be under the care of a health care provider from the Instituto Mexicano del Seguro Social (IMSS) 8. Available for the duration of the study.