This is a detailed description of the methodology and collection of data, as well as an elaboration of the conclusions, performed by the authors in their controversial article "A Randomized Controlled Trial of Prenatal Nutritional Supplementation in New York City" (Pediatrics 1980;65:683-697).
Starting with approximately 800 mothers who were expected to have been deprived of protein, the authors gave to one third a protein supplement, to one third a balanced protein-calorie supplement, and to one third routine clinical care. After recruitment of the study groups, it was found that the nutritional deficiency most likely to be present was one of calories rather than protein.
The high-protein supplement seemed to have an adverse effect on the outcome of some pregnancies, despite increased maternal weight gain. Some psychological effects at 1 year of age may have been produced by the high-protein supplement during pregnancy.
This study is bound to be quoted frequently