Why Decades of Dairy Fat Research Might Be Wrong

By Julia Reedy, MNSP, October 25, 2021

dairy researchWhen it comes to dairy products, skim milk reigns supreme as the epitome of health and dieting. Butter, on the other hand, elicits the opposite mental image.

But what if we told you that our collective aversion to dairy fat was unjustified? Well, recent research suggests exactly that. So, if you've been looking for an excuse to eat more brie or less fat free cottage cheese, keep reading. 

Vitamin D helps the body absorb calcium from dairy foods. Get to know vitamin D here.


First, a quick introduction to dairy

Sometimes, phrases like “lowfat” or "reduced-fat" can seem like generalizations. But when it comes to dairy, they actually refer to very specific amounts:

  • Cream (36-40% fat): The more fat-concentrated portion of whole milk that floats to the top during separation. The main component in things like ice cream, whipping cream and crème brulee.
  • Full-fat (3.25% fat): Whole milk or any of its products, like cheese or whole milk yogurt.
  • Low/reduced-fat (1-2% fat): 1% and 2% milk, or low-fat yogurt and reduced-fat cheese.
  • Fat-free (0% fat): Skim milk and foods like fat-free yogurt or fat-free ice cream.


What we've been taught

For decades, research has told us that intake of saturated fatty acids is heavily associated with an increased risk of obesity, cardiovascular disease (CVD), diabetes, and other diet-related illnesses. So it was no surprise that the first-ever Dietary Guidelines (published in 1980) encouraged Americans to “avoid too much fat, saturated fat and cholesterol,” and to do so by opting for the low-fat variety of foods like meat, poultry and dairy.1

Since then, fat-free and low-fat dairy products have experienced a significant surge in popularity, while their full-fat friends have been living in the shadows. But, right alongside the low-fat dairy zeitgeist, starting around 1980, came the obesity and diabetes epidemic. So what gives? Has all this research somehow been wrong? Is what we’ve been subsequently taught about dairy wrong?


almond milk vs cow milk

The study at hand

In 2015, researchers at the University of São Paulo published a study that put dairy standards into question. Using a cohort of nearly 1,000 adults, they observed the association between high and lowfat dairy intake and Metabolic Syndrome (MetS) diagnoses. MetS is a diet-related disease and is diagnosed when a person displays at least 3 of 5 criteria: high waist circumference, high serum triglycerides, low HDL cholesterol, high blood pressure, and/or high fasting glucose (‘high’ or ‘low’ specifically defined for each criterion). Subjects were given Food Frequency Questionnaires (FFQ) to determine their intake of a variety of foods, and had measurements for MetS criteria taken.2

Simply put, the results showed an intake-dependent inverse relationship between total dairy intake and MetS risk, meaning the more dairy someone consumed, the less likely they were to develop MetS. And here’s the kicker: this association was mimicked when researchers focused solely on full-fat dairy products, but it was not found with only low-fat ones. And in a conclusion utterly contradictory to what we’ve been taught, the researchers determined the beneficial effects from high-fat dairy were due to increased consumption of saturated fatty acids (SFA).2


What should you do with this information?

First things first: this study concluded SFA from dairy had beneficial effects, and did not focus on total dietary SFA. So don’t run out and have a triple bacon cheeseburger in the name of science.

We also must note that even all full-fat and cream-based dairy products are not created equally; yogurt and butter intake, for example, had the most beneficial effects on MetS risk, while desserts like ice cream and pudding – regardless of fat content –increased the risk for development.2 A 2017 study, on the other hand, found non-fermented dairy (milk and butter) to be detrimental to health while fermented dairy (yogurt and cheese) were beneficial, regardless of fat content.3

There were, as is normal, limitations to this study. The manner by which researchers collected data leaves room for error, as subjects might not have been totally accurate in their FFQ reporting. It’s also possible that other factors came into play; full-fat dairy eaters tended to exercise more, drink less, and eat more fruits and vegetables than the low-fat group. There may also be differences in the dairy products themselves that have an effect; low-fat products might have added salt or sugar, both of which can have negative health implications.

This study isn’t the only of its kind; multiple others have come to similar conclusions. So at the very least, decades-old recommendations for low-fat and fat-free dairy products may be obsolete. The jury is definitely still out.

Key takeaways

  • If you’re looking to up your intake of full-fat dairy foods, try recommended serving sizes of whole milk yogurt or butter. Fermented products (like kefir) and cheese are runners-up.
  • Full-fat dairy products tend to contain more calories than their low-fat or fat-free counterparts. When adding full-fat dairy to your diet, be wary of caloric content.
  • Low-fat and fat-free dairy products are not the enemy, especially for those looking to reach a healthy weight. Just be mindful of added salt, sugar or fillers.



[1] https://www.dietaryguidelines.gov/about-dietary-guidelines/previous-editions/1980-dietary-guidelines-americans 
[2] https://pubmed.ncbi.nlm.nih.gov/26511614 
[3] https://pubmed.ncbi.nlm.nih.gov/28490510 

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