Dietary diversity involves adequate intake of macronutrient and micronutrient. The inclusion of animal source foods (ASF) in the diet helps prevent multiple nutrient deficiencies and any resultant, linear growth retardation. The objective of the current study was to assess the relationship between dietary diversity, ASF consumption and height-for-age z-score (HAZ) among children aged 12–59 months old across a 1-year observation. This longitudinal observational study without controls was conducted among four age groups: 12–23 months (n 57), 24–35 months (n 56), 36–47 months (n 58) and 48–59 months (n 56). Anthropometry and dietary intake were measured during each of four visits at 16–20-week intervals. The general characteristics and other observations were only collected at baseline and endline. During the year-long study period, approximately 27 % of the children ate a diverse diet (consumed ≥6 out of 9 food groups) according to ≥3 visits. ASF consumption was high, particularly for eggs, poultry, processed meats and liquid milk. Yet, micronutrient intake inadequacy, especially of Zn, Ca, Fe and vitamin A, was highly prevalent. A multivariate regression analysis showed that the consumption of a diverse diet and ASF was not significantly associated with the HAZ at endline, after controlling for demographic characteristics and the baseline HAZ. The consumption of a diverse diet was significantly associated with Ca intake adequacy. Moreover, ASF consumption was significantly associated with adequate intake of protein and micronutrients, particularly vitamin A, Ca and Zn. Thus, the recommendation is to continue and strengthen the promotion of consuming a diverse diet that includes ASF in supporting the linear growth of young children.