In this chapter, the unique nutritional challenges faced in less developed countries and regions are discussed, with a particular emphasis on the nutritional and health hurdles encountered by children. In particular, this chapter first delves into the undernutrition and malnutrition that stand as a major health threat to the vulnerable child population in underdeveloped regions. Then, the potential causes of this phenomenon (such as inadequate food consumption, deficiencies in essential nutrients, health education, and other factors) and the consequent nutritional health problems (growth retardation, cognitive impairment, and increased mortality) are also discussed. Conversely, overconsumption of nutrients, fueled by the encroachment of Western dietary habits and other societal shifts in certain underdeveloped areas, is also discussed in this chapter, which also poses its own set of dangers in the form of obesity, cardiovascular diseases, cancers, and other diseases. Notably, addressing both nutrient deficiencies and excesses in these underdeveloped regions necessitates integrated and comprehensive approaches such as improving dietary patterns, oral supplements, and nutrition education. For instance, micronutrient supplementation has proven efficacious in enhancing nutritional status among at-risk children; while nutritional supplements rich in energy are an important means to promote normal growth and development for children experiencing malnutritional issues. In conclusion, a balance in nutrient intake is of paramount importance for the health; while suitable nutrition interventions are often required to promote nutritional well-being of children in underdeveloped regions. Therefore, efforts in understanding the intricate interplay between poverty, food security, and implementation of nutritional interventions are key to design the comprehensive strategies to tackle both nutrient deficiencies and excesses prevalent in these underserved areas.