After the war, he returned to the Toronto General Hospital where he eventually became head of the research institute.
In 1923, he, along with physicians Alan Brown and Frederick Tisdale, helped work out the formula for Pablum, a processed cereal for children.
The cereal marked a breakthrough in nutritional science as it helped prevent rickets, a crippling childhood disease, by ensuring that children have enough vitamin D in their diet.
The ease of preparation made Pablum successful in an era when infant malnutrition was still a major problem in industrialized countries.
During World War II, Drake designed nutritional diets for RCAF personnel as well as for POW parcels.