Malnutrition is present in most countries of the world. This ranges from general undernutrition due to insufficient food, or poor-quality diets low in some essential nutrients, to overnutrition and obesity with energy-rich but nutrient-poor diets. The fundamental aim of dietary recommendations is to prevent deficiency diseases, and the assumptions which underpin these recommendations need to be understood when considering what advice to give to the general public or individual patients. This is particularly relevant in early life as the nutritional state and dietary intake of the mother are of major importance for both her and her baby's health. There is a particular concern with pregnancy in teenage women, as they are still likely to be growing and have different nutrient requirements compared to older women. There is now evidence of beneficial effects for both the mother and baby of supplementation of the mother's diet in those with a low nutritional status. For infants, early gut microbiome development is supported by human milk components (including oligosaccharides) and the reported health benefits are of growing interest and offer potential areas for future developments. Yet, the increasing overweight and obesity in children are a serious concern, in both developed and developing economies. Considerations of the achievements, challenges, and future directions of early life nutrition need to be addressed in a global environment in which every country in the world is experiencing some form of malnutrition. The term malnutrition encompasses a number of different scenarios ranging from undernutrition, which encompasses an inadequate nutrient intake in a diet with a low level of diversity, up to overnutrition where there is an excess of energy intake in a diet which is predominantly composed of nutrient-poor foods. The major feature of malnutrition is that there is micronutrient inadequacy, and even deficiency, which is particularly concerning in early life. The present chapter will consider the major achievements and future challenges in relation to achieving optimal nutrition in early life as well as in older children. Clearly, when considering nutrition in children, it is important to also consider the nutritional state of women before, during, and after pregnancy, as this can have a major impact on the fetus and young child. Before considering these issues in detail, this chapter will begin by addressing the basis on which nutritional recommendations are founded and the challenges that have to be met in getting novel recommendations approved by the appropriate authorities.