Impact of community-based health literacy intervention on food literacy, dietary behaviors, and nutritional status among adults in selected rural and urban areas of Tanzania

This study assessed the impact of the Interdisciplinary Health Literacy Program (IHLP) on food literacy, dietary behaviors, and nutritional status among adults in rural and urban Tanzania. The study employed a pre-post single-group design involving 410 adults who participated in all three study phases: Phase I (Baseline Study), Phase II (Educational Intervention/Implementation), and Phase III (Endline Survey/Evaluation). Baseline data were used to assess pre-intervention conditions and inform development of the IHLP content, while endline data were used to evaluate the intervention’s impact by comparing outcomes to baseline. Data collection tools included a semi-structured questionnaire, a validated food literacy tool, the Global Physical Activity Questionnaire (GPAQ), a 24-hour dietary recall, and the seven-day Dietary Diversity Score (DDS), all of which remained consistent at both baseline and endline time points. Weight and height were measured to compute body mass index (BMI). Changes in pre-post for normally distributed data were analyzed with a paired t-test, and their association was assessed using Pearson’s correlation; changes in non-normally distributed data were analyzed with a Wilcoxon signed-rank test, and their association was assessed using Spearman’s rank correlation. McNemar-Bowker examined the impact of the IHLP on categorical variables. A multivariate regression analysis was performed to examine factors associated with dietary intake indicators and nutrition status. The majority of participants were women (71.2%), aged 30–39 (40%), had primary education (59%), and most households consisted of 1–4 members. In urban areas, 54.2% were employed in the formal sector, while 98.3% of rural participants were engaged in farming. After the IHLP, the mean food literacy score increased from 30 ± 8.54 to 35 ± 8.13, food group diversity increased from 3 ± 0.97 to 4 ± 1.04, and energy intake increased from 2063 ± 838.32 kcal to 2506.64 ± 925.13 kcal. BMI increased significantly (z = 0.93, p < 0.001), and metabolic equivalents (METs) decreased (z = -13.62, p < 0.001). Food literacy correlated positively with food group diversity ( r = 0.12, p = 0.02) and energy intake ( r = 0.13, p = 0.18). Higher food literacy and education levels among participants were positively associated with increased consumption of food from six recommended food groups. Higher education levels, male sex, and usual consumption of sugary foods were positively associated with higher energy intake, while male sex was negatively associated with changes in BMI. The IHLP improved food literacy and increased consumption of a diverse range of food groups, supporting its role in addressing malnutrition.