This study is interesting, if not conclusive. Meta-analyses lack a clear indication of cause and effect. For that reason, they are not the ultimate scientific research tool.
That being said, when a systematic review and meta-analysis reviews 28 studies from seven different countries and involves more than 21,000 kids between the ages of 1 and 18, the results should be taken pretty seriously. The review led by St. Michael’s Hospital of Unity Health Toronto is that study and should be taken seriously.
Researchers found that children who drank whole milk were 40 percent less likely to be overweight or obese. This was in comparison to kids who drank reduced-fat milk. Their results were published in The American Journal of Clinical Nutrition.
In all, 18 out of 28 studies reviewed indicated that consumption of whole milk by children made those kids less likely to be obese or overweight. None showed a link between consumption of reduced-fat milk and a lower risk of overweight or obesity.
The findings fly in the face of Canadian, American and international guidelines that direct children to drink reduced-fat cows milk instead of whole milk beginning at age 2. The conventional wisdom, along with a limited amount of scientific support, says this will reduce the risk of obesity as children get older.
“The majority of children in Canada and the United States consume cow’s milk on a daily basis and it is a major contributor of dietary fat for many children,” said Dr. Jonathon Maguire, lead author of the review and a pediatrician at St. Michael’s Hospital.
“In our review, children following the current recommendation of switching to reduced-fat milk at age two were not leaner than those consuming whole milk.”
Dr. Maguire, also a scientist at MAP Centre for Urban Health, would next like to determine the cause and effect link between drinking whole milk and the apparent reduced risk of obesity. The best way to do this would be to design a randomized controlled trial.
“All of the studies we examined were observational studies, meaning that we cannot be sure if whole milk caused the lower risk of overweight or obesity. Whole milk may have been related to other factors which lowered the risk of overweight or obesity,” Dr. Maguire said.
“A randomized controlled trial would help to establish cause and effect but none were found in the literature.”
For now, however, the conventional wisdom that drinking reduced-fat milk will help kids avoid overweight and obesity may not be so wise! Let the kids enjoy some good, old-fashioned whole milk with their meat and veggies!
Keep the faith and keep after it!
Journal Reference – 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