To inform programmes and policies that promote health equity, it is essential to monitor the distribution of nutritional problems among young individuals. Common nutritional problems include overall low diet quality, the underconsumption and overconsumption of certain dietary components, unhealthy meal and snack patterns, problematic feeding practices and disordered eating. The objective of the present narrative review was to summarise recent evidence of disparities among US children (2–19 years) according to age, sex, socio-economic status, ethnicity/race and rural–urban location. Searches in PubMed® and MEDLINE® were completed to identify peer-reviewed research studies published between January 2009 and January 2019. Findings from the ninety-nine reviewed studies indicate adolescent females, young individuals from lower socio-economic households and individuals who identify as non-Hispanic Black race are particularly vulnerable populations for whom targeted strategies should be developed to address evidence of increased risk with regards to multiple aspects of nutritional wellbeing. Limitations of the existing evidence relate to the accuracy of self-reported dietary data; the need for consistent definitions of disordered eating; the focus on individual dietary components v. patterns; the complexities of categorising socio-economic status, ethnicity/race, and rural and urban areas; and the cross-sectional, observational nature of most research designs. There is an urgent need for research to address these limitations and fill a large gap in evidence on rural–urban differences in nutritional problems. It will further be important for future studies to build greater understanding of how nutritional problems cluster among population groups.