Cow’s Milk Fat Obesity pRevention Trial (CoMFORT)
Dr. Jonathon Maguire, St. Michael’s Hospital


Childhood obesity is a looming healthcare crisis with 1 in 3 Canadian children now living with overweight or obesity. The long term consequences of childhood obesity include increased risk of cardiovascular disease, diabetes and stroke which reduce quality of life and longevity. Cardiovascular disease currently costs Canada’s health systems $7 billion annually and is forecasted to triple in the next 30 years. Since 1992 Health Canada has recommended that children older than 2 years consume reduced fat milk (i.e. 1% milk fat) rather than whole milk (3.25% milk fat) to prevent childhood obesity. Unfortunately, childhood obesity has tripled since then and whole cow’s milk intake has halved leading many to wonder whether the reduction in whole milk consumption is leading to childhood obesity. New research from our group and others supports that reduced milk fat intake early in life may be promoting rather than preventing childhood obesity. Although several biological mechanisms have been proposed, the leading theory is that children may feel more ‘full’ after consuming whole milk and less likely to seek calories from unhealthy foods.

Objectives and Trial Procedure

This innovative clinical trial will compare the effect of primary healthcare recommendation for whole (3.25%) vs. reduced fat (1%) milk in early childhood in optimizing childhood growth, development, and nutrition at 4 years of age. We will use new cohort trial methods leveraging Canada’s largest childhood cohort study (TARGet Kids!) to conduct this trial which will minimize cost and maximize feasibility. Children will be randomized to receive cow’s milk fat recommendations at their 2 year well child visit and followed until age 4 years through TARGet Kids! participation, when usual TARGet Kids! outcomes such as Body Mass Index z-score (zBMI), which is a measure of body fatness, cardiovascular health measured by a blood sample, and dietary intake through a dietary recall tool.

Importance of the Trial

This trial will ensure that primary healthcare providers are delivering the correct nutritional cow’s milk fat recommendation in early childhood and to protect the next generation of Canada’s children from the long term consequences of childhood obesity.