Low-fat vs whole-fat dairy: are both good for children?

New study suggests that switching to low-fat dairy foods does not lead to better health outcomes in children.


Whole fat dairy products are just as healthy for children as low-fat equivalents, according to a new study led by researchers from Edith Cowan University (ECU) in Perth. The study, led by Associate Professor Therese O’Sullivan from ECU, was published this week in The American Journal of Clinical Nutrition and is part of a broader project, called the Milky Way Study.

According to Analise Nicholl, a PhD candidate who co-led the study, the idea behind this new study was to shed some light on the common thinking that, from two years of age, children need to switch to low-fat dairy products to prevent weight gain and cardiovascular problems later on.

“Several decades of public health concerns that the excess calories and saturated fat content in whole-fat dairy products could cause weight gain and cardiovascular disease have undermined belief in the health benefits of this food group. Parents are confused about which types of dairy products are the best choices for their kids,” said Analise Nicholl, a PhD candidate who co-led the study.

“We would like to make it easier for busy parents to make safe and healthy dairy choices for their kids. Our ultimate goal has been to influence public health policy: new Australian Dietary Guidelines have been in the pipeline since July 2020, and we hope our research can contribute useful information to help inform decisions about what should be included in the new paediatric guidelines,” she added.

About the study
The study measured, for the first time, how children’s obesity, body composition, blood pressure, and blood biomarkers were affected by changing to low-fat vs. whole-fat dairy consumption. Over a three-month period, 49 healthy children aged four to six were randomly allocated into one of two groups. One group received whole fat dairy products in place of their normal dairy intake, whereas the other received low-fat dairy products. All products were provided free and in plain packaging, to keep families and researchers blind to each child’s dairy group. A key finding of the study was that, regardless of the type of dairy consumed, children ended up consuming the same total amount of calories per day, and did not experience significant differences in obesity or cardiovascular health markers.

“It had previously been thought young children would benefit from low fat dairy products due to their lower levels of saturated fats and lower density of energy, in turn helping avoid obesity and risk of associated cardiometabolic diseases,” Prof O’Sullivan said in a press release.

“Our results suggest healthy children can safely consume whole fat dairy products without increased obesity or adverse cardiometabolic effects,” she added.

The logic behind these findings is that there may be differences in levels of satiety between children who consume whole-fat vs low-fat milk. In other words, giving children low-fat dairy products left them wanting for more, and they ended up getting the extra calories from other, less healthy options. “If replacing whole-fat dairy products with reduced-fat did not improve health outcomes, this could in part be due to effects such as reduced satiety, or reduced palatability: either way children may turn to less nutritious foods,” Ms Nicholl said.

In addition, low-fat dairy products may contain fewer health benefits after processing: for parents this means added sugars, but it can also affect levels of healthy microbes or probiotic components. “Wholefood milk, cheese and yoghurt all contain live cultures, or probiotics, largely associated with dairy fat. The considerable health benefits of fermented dairy products can be reduced or lost when dairy products have fat removed, or when plant-based alternatives are used,” she added.

The findings of this new study may help parents decide on what dairy products their children can consume, opening the door to letting them consume whole-fat products.

Researchers at the Milky Way Study are now looking at other questions around this topic. For example, they are they are investigating changes in levels of fatty acids in the children’s blood samples, before and after they changed to the Milky Way Study whole-fat or reduced-fat dairy products. Here, their goal is to establish if there is a link between levels of fatty acids with cardiometabolic health risk. Other projects are looking more closely at what food choices kids make when following a diet based on low-fat dairy products, and how different dairy fat levels affect a child’s gut microbiome.