The present study examined the nutritional status of children under 6 years of age and related factors in Kalar city, Iraq. Our analysis indicated that the highest rate of overweight was observed in boys at 24 month (61.4%). The lowest prevalence of underweight was observed in children at the birth time (0.44%) and only mothers with academic literature had significantly higher BMI for age compared to mothers with lower education. Our findings also showed that stunting was more prevalent among boys than girls in 0–6 years old children.
Malnutrition (stunting, wasting, and overweight) in children, especially in preschool children, affect the intellectual [14, 15] and physical development  in childhood and increased the risk of adulthood obesity and unfavourable cardio-metabolic consequences , the growth trend and nutritional status of preschool children are one of the major priorities for health systems.
In a cross-sectional study  performed on 15,408 children under the age of 6 years in Fars province, Iran, the rates of wasting, stunting, and underweight were 8.19, 9.53, and 9.66%, respectively. Similar to our study, stunting rates were higher among boys than girls. In this study, the stunting rate was significantly associated with lower mothers' education and lower family income. Also, the large dimension of family and lack of access to health services were related to being underweight and wasting, respectively. In another study  of 65,908 pre-school children aged 2 to 7 years in Luoding city, China, the prevalence of overweight and obesity increased from 3.70% to 7.27% and 1.04% to 2.08%, respectively. Meanwhile, the wasting reduced from 0.91% to 0.72%, and stunting decreased from 9.29% to 5.22% from 2004 to 2013. This trend does not provide satisfactory results. In recent decades we have encountered a phenomenon called abdominal satiety (versus cellular satiety), especially in low-income countries, where children appear obese while suffering from cellular malnutrition [20, 21].
In our study, the rate of stunting was highest among 6-month-old boys, while in the study of EN Muchina et al.,  Which performed on 418 Kenyan children aged 0–24 months, the rate of stunting among children aged 7 to 12 months was three times higher than 0–6 months. Also, our analysis indicated that the highest rate of overweight was observed in boys at 24 month, while in this study, underweight increased with age up to 24 month and wasting was at the highest level in children 13–24 months. Also, in Chandigarh-India , proportions of underweight (45.5%) and stunting (81.8%) were found to be maximum among children aged 13–24 months.
In general, the difference in the prevalence of undernutrition in different parts of the world is related to various risk factors such as child’s gender, children's health care, health status and rates of infectious diseases, breastfeeding, family socioeconomic status, mother's education, pre-pregnancy weight, ethnicity, and family size.
The results indicated a higher prevalence of stunting in boys compared to girls. This finding was supported by other researchers; their studies revealed that boys due to vulnerability to childhood diseases may be at higher risk for stunting [24–26].
Our results also revealed that children of mothers with academic literature had significantly higher BMI for age compared to those of mothers without formal education. In agreement, previous studies reported a higher prevalence of undernutrition in children of mothers with lower educational levels [24, 27]. In the study of Kavosi et al. , the prevalence of stunting was lower in children whose mothers had an academic education than in children whose mothers had a diploma or less. Educated mothers can become more aware of their children's nutritional status and improve their children's growth process through better and more efficient health services usage and prevent malnutrition [24, 27–29]. The main strength point of our study is that it was the first study to assess the children's nutritional status in Kalar city.
The limitation of our study is that information regarding gestational age, family income, and breastfeeding status was not accurately provided.