A culture-sensitive semi-quantitative FFQ for use among the adult population in Nairobi, Kenya: development, validity and reproducibility

Abstract

Objective: To develop a semi-quantitative FFQ and to evaluate its validity and reproducibility for the assessment of total dietary intake of Kenyan urban adult population, given its non-existence in Kenya. Design: The current study adopted a cross-sectional design. A culture-sensitive semi-quantitative FFQ was developed and its validity was tested relative to three non-consecutive 24-h recalls (24hR). Reproducibility was tested by the test–retest method, with a 3-week interval. Spearman’s correlation coefficients and intra-class correlation coefficients were calculated for several macro- and micronutrients. Cross-classification into quartiles and Bland and Altman plots were analysed. Setting: Nairobi county (Dagoreti South and Starehe constituencies). Participants: A convenient sample was recruited in three different clusters in Nairobi. Results: A culture-sensitive 123-food-item semi-quantitative FFQ showed higher nutrient intakes compared with the 24hR (total energy median 12543·632 v. 8501·888 kJ, P < 0·001). Energy-adjusted and deattenuated Spearman’s correlations for macronutrients ranged between 0·21 (total fat) and 0·47 (protein). The agreement in the same quartile varied from 28 % (protein) to 41 % (carbohydrates). Including adjacent quartiles, the range increased: 76 % (protein and fat) to 81 % (carbohydrates). The extreme disagreement was low. The first FFQ application resulted in higher mean values for all nutrients compared with the second FFQ (total energy median 12459·952 v. 10485·104 kJ, P < 0·001). Energy-adjusted correlations for macronutrients ranged from 0·28 (carbohydrates) to 0·61 (protein). Intra-class correlation coefficients for macronutrients were moderate, between 0·6 and 0·7. Conclusions: The developed semi-quantitative FFQ was shown to be a valid and reproducible tool for ranking urban adult Kenyans according to their dietary intake.

Nutritional intake and food sources in an adult urban Kenyan population

“…A previously developed and validated semi‐quantitative FFQ (Vila‐Real et al, 2020), relative to the previous month's consumption, was used to study the dietary intake of the sample. The FFQ included 123 food items distributed over 11 food groups (Table 1).…”

“…In order to transform the food information into the nutrient intake, the Food Processor® software, version SQL 11.0.3 (ESHA Research) was used. Details about the methodology followed can be found in Vila‐Real et al (2020). Briefly, the information from the FFQ was introduced in a Microsoft Access® database, for further crossing with Food Processor®.…”

“…Also, the large amount of statistical testing to study the associations between food sources and participants' characteristics might increase the likelihood of false positive findings, especially since the adjustment for multiple testing was not carried out. As previously discussed (Vila-Real et al, 2020), some difficulties were found in the estimation of the amounts consumed of certain types of foods.…”