For decades now, people have been saying you should eat low-fat.

The idea was that fat was destructive and led to cardiovascular issues.

Dr. Wiggy has long said that healthy fats are something you should consume copious amounts of, especially if you’re using a ketogenic diet.

Dairy has always been one of the foods that has been stripped of fat.

And maybe that’s going to change.

A controlled study found that adults could eat three servings of full-fat dairy each day without gaining more weight or developing worse cholesterol, insulin resistance, or body composition changes.

People have denounced high-fat dairy because of the concern that saturated fat could have negative effects on heart health.

But food is rarely that simple.

Researchers at the University of Toronto recruited 74 adults who were overweight or suffered from obesity and assigned them to one of three diets for 12 weeks.

One group ate very little dairy while reducing calories.

A second group ate three servings of dairy each day but kept calories around the amount their bodies needed.

A third group also ate three servings of dairy without calorie limits.

The researchers wanted to see whether dairy itself caused problems, separate from the effects of eating fewer calories.

It didn’t.

After 12 weeks, the groups eating more dairy did not show meaningful increases in body weight, body fat, blood cholesterol, or insulin resistance compared with the low-dairy group.

They also had lower blood pressure and consumed more calcium, protein, and vitamin D.

Why Saturated Fat Isn’t Straight Up “Bad”

Many nutrition guidelines still recommend low-fat or fat-free dairy because full-fat products contain more saturated fat.

The concern is understandable. High intake of certain saturated fats can raise LDL cholesterol in some people, and LDL is linked with cardiovascular risk.

Still, studies of full-fat dairy have not consistently shown worse health outcomes. Some have even found possible benefits.

One reason may be what researchers call the dairy matrix.

That phrase describes the way proteins, fats, minerals, and other nutrients are packaged together inside a food. In dairy, casein, whey, fat, calcium, and other components are not consumed separately. They interact during digestion.

That structure may change how slowly nutrients are absorbed and how the body responds to them.

In other words, eating cheese is not the same as eating a spoonful of saturated fat. Yogurt is not simply fat plus protein plus calcium added together on a nutrition label.

The whole food may behave differently than its individual parts.

Why This May Matter for Older Adults

The findings could be especially useful for older adults.

As people age, they often need fewer calories while still requiring enough protein, calcium, vitamin D, and other nutrients.

That can be a difficult balance, particularly when appetite drops.

Full-fat dairy can provide a fairly concentrated source of nutrition. For someone who struggles to eat enough, that may be useful.

It can also be more satisfying and easier to enjoy than a product that has had most of its fat removed.

That does not mean everyone should suddenly start eating unlimited cheese, butter, or cream. The study was small, lasted only 12 weeks, and involved three servings of dairy, not an unrestricted high-fat diet.

People with high cholesterol, cardiovascular disease, lactose intolerance, milk allergy, or other medical concerns may need more individualized guidance.

The study suggests that full-fat dairy can fit into a balanced diet without automatically causing weight gain or poor metabolic health.

It also supports a broader shift in nutrition research, something Dr. Wiggy supports. Foods should not always be judged by one nutrient alone.

For many people, the better question is not whether a product is full-fat or low-fat.

It is how much they are eating. What else is in the diet? And whether the food helps them meet their nutritional needs?

Milk, yogurt, and cheese can provide protein, calcium, vitamin D, and energy in a familiar form. Low-fat versions may still be the right choice for some people. Full-fat options may work just as well for others.

The practical advice is fairly ordinary. Eat a varied diet, pay attention to portions, and choose foods that support the bigger picture of health.