La Diabetes

Clinical Care/Education/Nutrition
O R I G I N A L A R T I C L E

A Flexible, Low–Glycemic Index Mexican-Style Diet in Overweight and Obese Subjects With Type 2 Diabetes Improves Metabolic Parameters During a 6-Week Treatment Period
ARTURO JIMENEZ-CRUZ, MD PHD1 MONTSERRAT BACARDI-GASCON, MD EDD1 WILFRED H. TURNBULL, PHD2 PERLA ROSALES-GARAY, MD MSC1 ISIS SEVERINO-LUGO1 associations between the GIand/or GL and control of blood glucose, despite the imprecision of the measures (8,12). Results from two large prospective studies, the Nurses’ Health Study (7) and the Health Professionals’ Follow-Up Study (13), showed a positive association between a high-GI diet and risk of developing diabetes. On the other hand, there have been studies examining the incidence of type 2 diabetes in AfricanAmericans (14) that showed no association of GI and GL with diabetes risk. In a recent study conducted in Australian overweight subjects, eating a low-GI diet showed a reduction of A1c, triacylglycerol, and LDL cholesterol after 12 weeks of treatment (15). Another study using a low-GI diet in healthy French men demonstrated a reduction of fat mass and triacylglycerol after a 5-week period (16).However, we have not found long-term studies showing the effect of low-GI diets containing Mexican-style foods on either Mexicans or Mexican Americans with diabetes. The typical Mexican diet includes beans (legumes) and corn tortillas (traditionally made), which are foods with a low GI. However, in Mexico and in the U.S., current dietary guidelines for people with diabetes focus on lowering dietary fatand increasing carbohydrate intake but do not mention the GI (17,18). The aim of this study was to compare the effects of a lower and higher GI and flexible Mexican-style diet on biochemical data and BMI during a 6-week treatment period. RESEARCH DESIGN AND METHODS Subjects Thirty-six subjects with type 2 diabetes (age, 53 9 years; range, 35–75 years), and a mean diabetes duration of 8 7
1967OBJECTIVE — The aim of this study was to compare the effects of a flexible lower– and higher– glycemic index (GI) Mexican-style diet on biochemical data and BMI during a 6-week treatment period. RESEARCH DESIGN AND METHODS — This study was a randomized, crossover design of two 6-week periods with a 6-week washout period between treatments. Subjects with type 2 diabetes (n 36) with a BMI 25 kg/m2 wereselected. Fourteen subjects completed the study with eligible dietary records. Dietary instruction was provided on flexible diets with both a high and low GI. Fasting venous blood samples were taken at the start and finish of each dietary period, and biochemical data were analyzed. Multi- and univariate one-factor repeated-measures ANOVA were used to compare biochemical data. RESULTS — Glycemic loadand GI were lower during the low-GI diet, and dietary fiber was lower during the high-GI diet. The participants in the low-GI period consumed significantly fewer carbohydrates, such as white-wheat bread, white long-grain rice, potatoes, high-GI fruits, and carrots, and more carbohydrates, such as pinto beans, whole-meal wheat bread, and low-GI fruits than did participants in the high-GI period.There were no differences in the amount of carbohydrates consumed, such as corn tortillas and dairy products. At the end of the study periods, A1c was improved on the low- compared with the high-GI diet (P 0.008). CONCLUSIONS — We conclude that a low-GI diet, containing Mexican-style foods, may help to improve the metabolic control in type 2 obese diabetic subjects during a 6-week period. DiabetesCare 26:1967–1970, 2003

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n Mexico, the incidence of diabetes has been increasing, and this epidemic is likely to continue to escalate. The prevalence of diabetes increased from 8.2% in 1993 to 11.8% in 2000. In Mexico City, the central and southern states, and among underprivileged people (including the Mexican Indians), the prevalence of diabetes increased to 14% (1). It is well established...