A new Canadian study offers another reason why childhood obesity rates have soared in the past 30 years.
In the latest challenge to the low-fat mantra that has dominated dietary convention for a half century, new research suggests that children who drink whole-fat milk are less likely to be overweight than those who opt for lower-fat varieties.
The findings counter established dietary guidelines from the American Academy of Pediatrics, which recommends that children over age 2 drink low-fat or fat-free milk to prevent obesity. Those guidelines have helped reduce whole-fat milk consumption by half over the past 30 years. At the same time, childhood obesity rates have tripled.
Researchers at St. Michael’s Hospital in Toronto calculated the body mass index (BMI) of 2,745 children between ages 2 and 6, also taking blood samples to measure vitamin D levels. About half of the study participants drank whole-fat milk; the rest consumed various low-fat options. The study found that whole-fat-milk drinkers had a BMI that was .72 units lower than those who opted for low-fat milk — essentially the difference between a healthy weight and being overweight.
Those who drank whole-fat milk also had higher levels of vitamin D, says lead study author Jonathon Maguire, MD, a pediatrician at St. Michael’s Hospital.
“Children who drink lower-fat milk don’t have less body fat, and they also don’t benefit from the higher vitamin D levels in whole milk,” says Maguire. “It’s a double negative with low-fat milk.”
The vitamin D connection is clear, Maguire notes, because the higher fat content delivers more of the fat-soluble nutrient to the body. Also, increased body fat reduces the body’s ability to store vitamin D.
The reasons behind the BMI difference are open to debate, but Maguire suggests that lower-fat options leave children feeling less full than whole milk and results in more snacking throughout the day. Unhealthy snacks, especially, can slow metabolism, trigger inflammation, and produce weight gain.
For the latest on the low-fat debate, see “The Facts About Fat” in the November 2016 issue of Experience Life.
Craig Cox is an Experience Life deputy editor.