This study aimed to examine the association between dietary diversity and undernutrition of children aged 6 to 23 months in Tanzania. In this study, dietary diversity was found to be a protective factor against stunting (HAZ) and underweight (WAZ) among children in Tanzania. These results are consistent with results reported from other developing countries like Burkina Faso [19]; Bangladesh [30], Ethiopia [18], and others [16, 21]. Our study suggests that undernutrition can be reduced by improving the dietary diversity of complementary foods in Tanzania. This is supported by the fact that dietary diversity is a good predictor of dietary quality and micronutrient density in children [15, 31]. Therefore, generally, this makes dietary diversity one of the important factors that policy makers should adopt to improve the nutritional status of children in the country.
However, this study did not find an association between wasting and the dietary diversity of children using the MDD indicator. This is in line with findings from other studies [19, 32]. As a previous study from Ethiopia has shown, wasting is more likely to be associated with diseases or household food insecurity rather than dietary diversity [18]. This might be due to the fact that, wasting refers to acute malnutrition as a result of shorter-term episodes of inadequate feeding or illnesses [33].
Our study shows that only small proportion (26%) of children of 6 to 23 months old in Tanzania reached the MDD. This is identical to a finding by Ochieng et al. who looked at factors affecting household nutrition security in Tanzania, which also reported that 26% of children did not reach the MDD [27]. Overall, the present study shows that consumption of animal-source foods like meat, milk and eggs is not very common among children of 6-23 months in Tanzania. Similarly, the study by Ochieng et al. reported that meat and fish were consumed by less than 10% of children under five [27]. These outcomes are not surprising considering the seasonal and geographical unavailability of some foods, the restrictions imposed by traditions and possible financial constraints in Tanzania [34]. In this study, children who did not consume any meat were more likely to become stunted. This result corresponds with a survey of 12 to 59 months old children in Cambodia, which concluded that the consumption of animal-source foods was a protective factor against stunting and underweight [17]. Animal-source foods like meat, milk, eggs and poultry have a variety of micronutrients including vitamin A, vitamin B-12, riboflavin, calcium, iron and zinc that are difficult to obtain in adequate quantities from plant sourced foods alone [35]. Thus, insufficient intake of these nutrients may hinder the physical development of a child, resulting into stunting [2]. We therefore highly recommend that public health officials should educate parents and caregivers on the importance of animal-source foods for their children.
Moreover, our analysis emphasizes that the consumption of milk and dairy products is very beneficial for growing children. We found that non-consumption of milk products is a predictor of stunting among children. Failure to give any milk or dairy product at this critical age may result in protein imbalance [2]. Milk is one of the basic foods which can easily provide adequate nutrition when consumed regularly in relative small quantities and which can promote a child’s health and is available throughout the year [36]. Therefore, health education messages related to the importance of milk and dairy products as complementary foods is a critical public-health intervention in Tanzania.
Another interesting finding in this study was the association of Vitamin A fruits and vegetables with underweight among children. In this study, children who did not consume Vitamin A containing fruits and vegetables were more likely to become underweight. Similar findings were reported from a study among children in Ghana [21]. Also, previous research has shown a significant association between Vitamin A intake and undernutrition, but not among infants [37]. Vitamin A is known as an essential micronutrient for growth and immunity. Its deficiency is one of the most important cause of preventable childhood blindness and is a major contributor to morbidity and mortality from infections [37]. Therefore, lack of adequate Vitamin A intake may results in the increase of underweight children in the country. It is therefore important for mothers to increase the inclusion of foods rich in Vitamin A such as spinach, mangoes and papaya as complementary foods given to their children. These foods are relatively cheap in Tanzania and are easily accessible in both rural and urban areas for most of the year.
We also found that, children who did not consume any food made from grains or legumes were more likely to become wasted. In many countries including Tanzania, grains and cereals including maize, sorghum, millet and rice are among the first foods that are introduced at the beginning of the complementary feeding period to infants [9, 22, 23, 38]. These are very beneficial for the children because they are an excellent source of energy, vitamins and minerals [38]. Therefore, to reduce the prevalence of undernutrition, mothers should provide adequate foods that would provide adequate energy and all nutrients to their children.
However, it is important to mention some important limitation of this study. We only considered the dietary diversity as indicator of the overall quality of the child’s diet. This study did not take into account the quantity of the foods consumed, and is therefore not able to reliably predict that foods consumed met the required dietary intake. Also, due to the cross-sectional nature of this study, cause and effect relationship cannot be assured and we have to interpret our findings with caution. Additionally, some indicators of the nutrition status like stunting represent a long-term cumulative process, whereas the dietary information available in the TDHS reflects only the previous day before the survey. In addition, the responses given by mothers/caregivers are sometime based on their ability to recall types of foods and their desire to please the surveyor. In spite of the mentioned limitations however, this present study can shed light on how dietary diversity is likely to influence the development of undernutrition in Tanzania. Future, large scale studies are needed to identify the causal relationship between diet and the physical and mental condition of the children in Tanzania.