Evaluation of preference and postprandial effect of selected carbohydrate staples by very active manual workers in Nairobi, Kenya

In Kenya, the overwhelming reliance on “Ugali” continues to pose a major problem socially, economically, and politically. There is a general perception that Ugali has higher satiety and energy compared to other staple foods, making it a common choice by very active individuals. The objective of this study was to evaluate the preference and postprandial effect of selected carbohydrate staples by very active manual workers (VAMW) compared to less active groups in Nairobi, Kenya. A total of 322 questionnaires were administered to respondents categorized into three groups: very active manual workers (VAMW); and for comparison, two moderately active groups: civil servants (CS) and university students (US). Respondents were asked to indicate their main carbohydrate staple from a choice of six commonly consumed carbohydrate foods: Ugali, rice, chapati, Irish potatoes, bananas, and “others” [foods such as Githeri (mixed maize and beans), cassava, spaghetti, noodles, Sweet potatoes, and bread among many alternatives], explain reasons for preferences, describe how they felt when they did not eat enough food or when hungry, and indicate their meal frequency per day. The minimum sample size was determined using G*Power version 3.1.9.4. Data was analyzed using Excel Data Analysis Tools for Descriptive Statistics and Analysis of Variance, Scheffé’s test and G*power for Post hoc tests. Results indicated that Ugali was the main carbohydrate for 90% of the VAMW, compared to 79 percent of all respondents combined. The average number of meals consumed was 3, reported by 80% of VAMW compared to 59% of CS and 48% of US. Analysis of variance indicated a significant difference in the number of meals consumed by VAMW compared to that of Civil servants and University students; F (0.05, 2,330) = 13.089, P< 0.0001; and final Power (1- err prob) of 0.97. Pairwise comparison of the mean ranks indicated significant differences between the mean ranks of all foods, except for rice versus chapati, and Irish potatoes versus bananas where there was no significant difference. Results also indicated that the choice of main staple by VAMW depends on energy value, occupation, and satiety index. Satiety of the foods depends on carbohydrate type, carbohydrate factor, glycemic load, quantity, and the combination with other nutrients.