In this study, about 26.1% of lactating mothers were undernourished. Under nutrition was more common among mothers who are unable to read and write, those who experienced high number of pregnancies, those with high family size, those who reside in the household with no toilet, and those who have less than four ANC visits for their last pregnancy.
The prevalence of under nutrition in this study was comparable with findings of study conducted in Rayitu district of Ethiopia (24%) (13), Alamata, Tigiray (24.6) (14) and Womberma district of North West Ethiopia (25.4%) (15). However, the prevalence is lower than study conducted in Samre district of Tigray (31%) (3), and Dedo and Seka chekors’s of Jimma district (40.6%) (16). The difference might be as a result of improvement in nutritional education, improvement in socio-economy and difference in geographical setting. But, the finding of this study is higher than study conducted in Tanzania (11%) (17), Nigeria (5%) (18), Nekemte town (20%) (2), Ambo districts (21.5%) (19), and Offa district of Wolayta zone (15.8%) (20). The reason for this discrepancy may be due to difference in socio-economy, geographical settings, and seasonal variation.
Mothers who are unable to read and write were almost four times more likely to be under nourished compared to those who have secondary and above educational level. This finding is consistent with studies conducted in Bangladesh (21), Ambo district (19), Adama district (22), and Offa district (20). The possible reason may be since those who are able to read and write can get nutritional information through reading books, posters and magazines than those who are unable to read and write.
Respondents who experienced 5–6 pregnancies were 2.5 times more likely to be under nourished compared to those who experienced 1–2 pregnancies. The finding of this study was inconsistent with study conducted in Alamat highland of Tigray in which respondents who have higher pregnancies were 44% less likely to be undernourished compared to those who lower pregnancies (14). However, this finding is supported by study conducted in Babile, Ethiopia, which shows, as parity increased by one unit, the BMI of the lactating mothers decreased (23). The possible reason may be, because of the fact that, as the number of pregnancy increases, exposure to different health problems including under nutrition may occur. In addition, the mother herself may be biologically depleted from too frequent births, which could also negatively affect the nutritional status of herself and her newborn.
Respondents whose family size is greater than four members were 2.29 times more likely to be under nourished compared to those who have less family size. This finding is supported by the study conducted in Womberma district of North West Ethiopia (15) and Nekemte town (2). This may be due shortages of food in the household with high family size, and culturally mothers always eat least food (some time leftover) at the last which leads to under nutrition.
Respondents who have toilet were 6.4 times more likely to be undernourished compared to their counterparts. This is supported by study conducted in Adama district (22). The reason might be due to the fact that, open defecation, because of lack of toilet results in an increased risk of diarrheal disease, which might contributes to under nutrition. In addition, poor handling and disposal of household wastes including human excreta are major causes of environmental pollution, which creates breeding grounds for pathogenic microorganism that causes under nutrition.
Respondents who visited ANC < 4 times were two times more likely to be undernourished compared to those who visited ≥ 4 times. This finding is consistent with the study conducted in Samre district of Tigray (3) and Rayitu districts of Ethiopia (13). This may be because of the fact that, ANC time is a time when nutritional information and other support for healthy behaviors is widely provided and might contribute to the lower probability of getting under nutrition.