Abstract:
The GlycaemicIndex (GI) of foods is a widely recognised tool for the dietary management of chronic diseases, especially Type 2 Diabetes Mellitus, a metabolic disease associated with life threatening complications and reduction in quality of life. Existing dietary management uses information on GI of single foods but, data on GI of mixed meals ‘as eaten’ may be more useful.However,available data on GI of mixed meals are limited. This study was designed to determine the GI of commonly-consumed mixed meals ‘as eaten’ by apparently healthy young adults in southwestern, Nigeria.
This quasi-experimental study involved 120 volunteers screened for Fasting Blood Glucose (FBG), Proteinuria, Body Mass Index (BMI),haemoglobin and Blood Pressure (BP) after which 80 apparently healthy young adults were selected. Following a 10–12 hour overnight fast, each participant was made to consume 50g of glucose dissolved in 350ml of water.Fifty-two (52) mixed meals and Eighteen (18) single foods were identified as test mealsfrom theRoots and Tubers (RT), Cereals and Grains (CG) and Legumes food groups. For each test food, 8 participants were randomly selected and served a meal containing 50g available carbohydrate. Each participant served as his/her control with a day (wash-out) period allowed between meals. Capillary blood samples obtained by finger prick were used to determine blood glucose concentrations with aglucometer at 0, 30, 60, 90 and 120 minutes. Blood glucose curves were constructed to calculate the GI of test meals with values classified as high (70 – 100), intermediate (55 – 69) and low (˂ 55).Data were analysed using descriptive statistics and ANOVA at α0.05.
Participants age was 22.28±3.49 years, BMI 20.96±2.31 kg/m2, FBG 84.74±6.59 mg/dL, haemoglobin 13.64±1.26 g/dl, and BP 112.19/72.45±11.55/8.75 mmHg. For the RT products: eba+efoelegusi, fufu+ewedu soup and fufu+okra souphad GI values of 74, 78 and 80, respectively. Amala+eforiro and amala+okra soup had a GI of 75 and 78. Same GI value (84) was obtained for amala+efoelegusi, pounded yam+okra, and boiled yam+fried egg. The CG: white rice+stew+fried plantain had GI of 74; while GI of 76 was obtained for white rice+stew+boiled beans and ogi+moin-moin. Ogi+akara had a GI of 77. The Legumes: boiled beans+stew, boiled beans+stew+ plantain and beans porridge had GI of 83, 84 and 85, respectively. The GI of eba (99) and amala(97) as single foods, was reduced to (74, 75), respectively when consumed with efoelegusi and eforiro. The GI values of eba, amala, whiterice, ogi as single foods were significantly higher than when eaten as mixed meals.However,eba+efoelegusi, white rice+friedplantain+stew, had the least GI of 74, while beans+garri (soaked), eba+ewedu andamala+ewedu, had the highest GI of 93.
Commonly consumed mixed meals in southwestern Nigeria have high GlycaemicIndex. However, the more diversified the meals, the lower the glycaemicindex when compared to single foods. To improve the GlycaemicIndex of mixed meals, further evidence-based research on reduced varied mixed meals portion sizes “as eaten” is recommended.
