In February 2019 researchers from the USA published their review of the medical scientific literature to assess whether animal source foods, such as eggs, meat, fish, and dairy, improved growth and developmental outcomes in children aged 5 to 50 months when compared to other foods. A total of 6 studies, involving 3,036 children, were included in the review. The studies were conducted in the following countries and had lasted between 5 and 12 months: China, the Democratic Republic of Congo, Ecuador, Guatemala, Pakistan, the USA, and Zambia. Results were inconsistent. Some showed that children with an intake of animal source foods, when compared to those on a more cereal based diet, had a significant increase in height for age scores whereas another study found no difference. In a study comparing a meat-based diet with a dairy-based diet, there was a significant increase in height for age scores among infants consuming the meat-based diet whereas it was significantly decreased in infants consuming a dairy-based diet. Some studies showed that children with an intake of animal source foods also had an increased weight gain whilst in others there was a decreased weight gain. One study, involving children who consumed yoghurt, found that they experienced a significant reduction in duration and incidence of diarrhea and upper respiratory infections. However, in another study, where the children consumed eggs, there was a significant increase in the incidence of diarrhea, although it was noted that cultural associations may have had a part to play in this finding. Overall the researchers rated the quality of evidence as being very low and because of this they were uncertain whether animal-source food had any impact on the growth and development of children when compared to cereal products or other foods.
Eaton JC et al. Effectiveness of provision of animal-source foods for supporting optimal growth and development in children 6 to 59 months of age. Cochrane Database Syst Rev. 2019 Feb 19;2:CD012818.