Providing your children with healthy food choices is an important role for any parent. When it comes to dairy products, a lot of research has been conducted to assess the impacts of different types of milk and milk alternatives on the health of children. Recently, researchers looked at the relationship between whole milk (3.25%) and childhood overweight and obesity—with interesting results!
A systematic review and meta-analysis led by paediatrician, Dr. Jonathon Maguire, at St. Michael’s Hospital of Unity Health Toronto explored the relationship between whole milk consumption in children and childhood overweight and obesity. The terms overweight and obesity are used in the review to refer to childhood fat mass using a selection of indicators from the studies.
The systematic review included 28 studies from 7 different countries that analyzed the relationship between childhood body mass and milk consumption in over 20,000 children aged 1–18 using markers including BMI (body mass index), age for weight, and body fat mass. When the data from all the studies were looked at together (called a meta-analysis), the findings suggested that children who consume whole milk have a lower BMI than children who drink reduced-fat milk. The results showed a dose-response relationship, meaning the higher the milk fat, the lower the odds of overweight and obesity. Overall, children who drank whole milk had 40 percent lower odds of being overweight or obese compared to those who drank reduced-fat milk1.
What are Canadian Milk-Drinking Habits?
In Canada, 88% of children between the ages of 1–3 and 76% of children between the ages of 4–8 consume cow’s milk daily1 and 94% of adults choose dairy products on a daily basis2. Currently, Canadian recommendations are to offer whole milk (3.25%) to children aged 9–24 months old3. This study opens a new opportunity for further research to guide recommendations for children over the age of 2 years old.
What is the Difference Between Skim Milk, 1%, 2%, and Whole Milk?
During milk processing, the milk fat is removed, making skim milk. The fat is then added back to make up either 1%, 2%, or 3.25% of the milk. Whole milk (or homogenized milk) refers to milk with 3.25% milkfat. Milk with higher fat content provides a greater amount of energy through calories. All cow's milk naturally contains calcium and is fortified with Vitamin D. Read more about calcium and vitamin D here.
Why is Low-Fat Milk Associated with Higher Weight?
If children are consuming low-fat milk, why is there an increased risk for overweight and obesity? According to the researchers in the study, more work needs to be done to understand if drinking low-fat milk causes greater body weight. Nevertheless, there are some hypotheses for the relationship:
Dietary fat provides a sense of satiety to the consumer. In the case of low-fat milk, the child may feel a lower sense of satiety than with whole fat milk. This can lead to an increased appetite and higher intake of other foods and drinks to satisfy their needs. These children may choose higher-calorie foods or sugary drinks, which may result in a higher caloric intake compared to whole milk drinkers.
Secondly, there may be a reverse relationship where larger children are more likely to drink low-fat milk. Parents with larger children may choose to provide their children with 1% or skim milk in an attempt to restrict the number of calories that the child consumes4.
Thirdly, restricting food intake is associated with overeating. According to Ellyn Satter's division of responsibility, parents should not restrict the type and amount of food a child receives in an effort to prevent weight gain5.
So what Should You Do?
The study tells us that there is an association between milk fat and childhood obesity, however, it cannot tell us if milk fat causes obesity. For this reason, making a milk choice based on its impact on childhood obesity is not yet warranted. All cow's milk are rich sources of protein, calcium, and vitamin D regardless of fat level. When choosing milk fat content for your children, pick the one they like the best.
- Shelley M Vanderhout, Mary Aglipay, Nazi Torabi, Peter Jüni, Bruno R da Costa, Catherine S Birken, Deborah L O'Connor, Kevin E Thorpe, Jonathon L Maguire. Whole milk compared with reduced-fat milk and childhood overweight: a systematic review and meta-analysis. The American Journal of Clinical Nutrition, 2019; doi.org/10.1093/ajcn/nqz276.
- Statistics Canada. (2018). Protein sources in the Canadian diet, 2015. Retrieved on January 14, 2020 from https://www150.statcan.gc.ca/n1/pub/11-627-m/11-627-m2018004-eng.htm
- Canada.ca. (2014). Infant Nutrition. Retrieved on January 8, 2020 from https://www.canada.ca/en/health-canada/services/infant-care/infant-nutrition.html
- Healthland (2013). Skim Milk may not Lower Obesity Risk Among Children. Retrieved on January 10, 2020 from http://healthland.time.com/2013/03/19/skim-milk-may-not-lower-obesity-risk-among-children/
- Ellyn Satter Institute. (2019). Helping Without Harming with Child Overweight. Retrieved on January 8, 2020 from https://www.ellynsatterinstitute.org/family-meals-focus/12-helping-without-harming-with-child-overweight/