The aim of the study was to assess energy intakes and dietary nutrient adequacy and their food sources during lent fasting and non-fasting periods among rural 6–23 months old children in Northern Ethiopia. In general, our findings indicated that children’s complementary diets were poor both in quantity and quality. The total intake of energy, protein and eight selected micronutrients by infants and young children were not in accordance to WHO/FAO  recommendations. Shortfalls of energy and nutrients were observed. This large shortfall for the diet of the study children may be explained, in part by the highest prevalence of child stunting (41.4%) in the study area.
Our study showed that cereals were the most ubiquitous along with legumes and nuts claimed to be fed by the children frequently. Only 7.1 and 2.3% of the infants and young children met the minimum dietary diversity of four or above food groups per day during the non-fasting period and the lent fasting period, respectively. Our finding was much lower than other studies from Ethiopia 21.8% , 59.9% , 38% , 27.3% , and (11.3%) . This could be associated with poor feeding habit, low economic status, poor nutrition knowledge, social norms, and beliefs among the study communities [13, 33, 37]. Thus, social and behavioral change communication and health interventions suggested to improve the feeding practices and stunting among infants and young children [13, 38].
Although 90% of household own at least one type of livestock; we have found that the consumption of a diet composed of meat was 4.5% in non-fasting period and (0.0%) during the lent fasting periods. These results are similar with a previous study in North West Ethiopia (0.0%)  and in Southern Ethiopia (1.6%) . This is further supported by previous evidence that households who owned some livestock, such as chickens, goats, and cows mainly used them as an income-generating activity rather than for home consumption . Thus, implementing appropriate nutrition education and improving the socioeconomic status of the community could advance the dietary diversity of infants and young children during the fasting and non-fasting periods [19, 40].
Inadequacy of nutrient intakes and micronutrient densities
The present study depicted that the average inadequacy of nutrients intake was particularly higher for energy (96.2%) and eight selected micronutrients (95.5%) compared to protein (44.9%) in both lent fasting and non-fasting periods. Although low adequacy intake has been reported from earlier studies in Ethiopia [17, 19] and Bangladesh , the severity of nutrient intake inadequacy was higher in our study children. This large shortfall in the diet of the study children could not be adequate for catch-up growth trajectory of the infant and young children in the study area.
It is evidenced that micronutrients are crucial for chemical processes that assure the survival, growth, and functioning of vital human systems ; yet, our study indicated that children who had received adequate intakes of energy and eight selected micronutrients was (1.6 and 2.4%, respectively) in lent fasting period and (4.9 and 7.3%, respectively) in non-fasting period. This could be due in part to inappropriate feeding practices  and low energy and nutrient density of complementary foods [17, 44, 45].
Complementary foods should contain ASFs or be fortified in some way especially for nutrients that must come from ASFs such as iron (97–98%) and zinc (80–87%) . However, the consumption of ASFs, mainly meat, by children in the study communities was lacking during the lent fasting period and low during the non-fasting period. The micronutrient intakes of these children were unlikely to achieve their estimated need because of the very low micronutrient densities of their complementary diets for all nutrients. Although the consumption of meat and eggs during the non-fasting period was higher than the lent fasting one, their contribution to nutrient intakes among the study children was inadequate at both periods, which did not allow time (fasting/non-fasting) variation in nutrient intakes to be considered. This is because the consumption level of different food groups in both periods was inadequate among infants and young children.
Although all of the nutrients received by the children were below the desired needs in lent fasting and non-fasting periods of all age groups, children were able to achieve better adequacy for protein and iron as compared to other nutrients. Indeed, similar to our findings, earlier studies reported that protein and iron nutrient densities met the desired needs of children [17, 46]. Others reported 100% inadequacy of nutrient intake for calcium and zinc across all age groups of the children during both periods of lent fasting and non-fasting. This may arise either from low or absence of foods rich calcium and zinc in the diets of children, which are mainly found in ASFs. Similar to the current findings, the highest deficiency of calcium was identified in the diets of infants and young children elsewhere in Ethiopia  and Bangladesh . Hence, extension services should specifically focus on educating women to own livestock for household consumption and cost-effective approaches are needed to ensure adequate intake of nutrients among children.
Contribution of food items to children’s nutrient intakes
Cereal-based foods largely contributed to the intake of nutrients among the study children. Sorghum in the form of porridge, bread and enjera was the children’s primary source of energy, protein, calcium, zinc, iron, thiamin, riboflavin, niacin, and vitamin C during both the lent fasting and non-fasting periods. Tef (Eragrostis tef) in the form of gruel, enjera and porridge was also the second most important food sources of nutrient intakes in the study population during both periods. In contrast, in Mexico, different food items such as soups, stews, sweetened bread, dried beans cookies, fruit, tortillas, milk, eggs, and traditional beverages were identified the top food sources of energy and nutrients among infants, toddlers, and young children . Similarly, milk has been reported as the most important source of energy and nutrient intakes among infants and toddlers in Philippines and China [48, 49].
In the study setting, children were served only single food items (sorghum and/or tef) at different times. This is consistent with a study conducted by Motuma et al.,  who reported that only one food item was processed into various forms and presented to the child at different serving episodes. Therefore, the observed high risk of nutrient inadequacy in the current study population may be attributed to the monotonous, chiefly plant-based diets. These results are largely supported by other dietary survey conducted among rural Zambian children of 4–8 years old .
Legumes (such as beans, chickpea, grass pea, peas, vetch, and lentils) were consumed by 58.9 and 49.2% of the infants and young children respectively in the religious fasting and non-fasting periods. As it is prepared in the form of shiro Tsebhi (stew) with very small amounts, its contribution to the children’s nutrient intake was low. The consumption of legumes in small amounts was similar for children of ages 24–48 months in Bangladesh . There is suggestive evidence that complementary foods that are mainly plant-based foods provide insufficient amounts of iron, zinc, and calcium to meet the recommended nutrient intakes for children of 6–23 months of age [29, 51]. Similarly, the principal sources of the above nutrients during both periods were plant source foods such as sorghum and tef in the form of gruel, bread, enjera and porridge across all age groups of the study children. Milk and eggs contributed respectively 18 and 6.6% in lent fasting period and 17.3 and 18.7% in the non-fasting period for the total calcium intake of the study children. In the same way, eggs contributed 12.6% of the total zinc intakes. Surprisingly, sesame, linseed, and enjera which were prepared from the mixture of sorghum and tef were good source of calcium in the study area. Another observation was that enjera and bread which was prepared by mixing of sorghum and maize were rich sources of iron. Thus, to improve the palatability and intake of nutrients among children, homemade/traditional food preparation and processing techniques such as mixing should be promoted [22, 44].
Egg was the most important food sources of vitamin A (71% of the total vitamin A intake) across all age groups of the study children. Only 12.5 and 34.7% of the study children consumed egg in the religious fasting and non-fasting periods, respectively. This indicates that other food items that were more consumed by the infants and young children such as sorghum had (0.0%) vitamin A content. The low consumption of egg among the study group is also comparable with a previous study in rural Tigray . With regard to B-vitamins, cereal foods such as sorghum and wheat for thiamin and sorghum and tef for niacin accounted for more than 50% of their total intakes. This is in line with earlier reports from Ethiopia, which showed that consumption of cereal foods was widespread [19, 52, 53]. Although only 10.1% children consumed dairy products, it contributed to 18.8% of the total riboflavin intakes- the second-highest source of riboflavin next to sorghum among the study children. Mengistu et al.,  also reported that dairy products were the highest sources of food groups for riboflavin intake among infants and young children. In addition to the presence of low vitamin A source foods, the consumption of other fruits and vegetables in the present study was 13.2%, which is comparable with the national figs .; Sorghum (63.8%) was the top source of vitamin C among the study population, contributing to the high prevalence of inadequate vitamin C intakes. These findings highlight the importance of nutrition education and intervention for the study children to improve their dietary structures based on the available resources.
Strengths and limitations
Data were collected from a representative sample to provide information about the broad assessment of energy and nutrient intakes, and their corresponding food sources among 6–23 months old children of the study area during the lent fasting and non-fasting periods. The collection of data during the lent fasting and non-fasting periods from the individual study population and the use of validated interactive 24-h recall technique to reduce recall bias were some of strengths of the study. However, this study had the following limitations. The study relied on caregiver’s ability to recall accurately on child food intake such as mixed dishes and supplements. Although efforts were made to search the foods that could match the equivalent foods in the national database, it was difficult to estimate the nutrient intakes from a mixed prepared food for those not listed in the national or other food composition database. This could also over or underestimate the nutrient intakes in this population. In such cases, calculation of the nutrient intake was made separately from the available food composition database. Temporal variation was not considered as the differences in dietary intakes in the harvest and lean seasons would influence dietary nutrient intake.