FATS ARE NOT THE ENEMY. We Were Afraid of the Wrong Thing.

The Problem Is What Kinds of Fats We Consume, in What Form, and Within What Metabolic Environment

For decades, the word “fat” was almost automatically associated with something harmful.

The logic seemed simple: fat raises cholesterol, cholesterol clogs the arteries, therefore we should eat as little fat as possible.

But human physiology is rarely that simple.

Today, we know that olive oil, salmon, eggs, butter, margarine and repeatedly heated frying oil cannot all be placed under the same label – “fat” – and be expected to affect the body in exactly the same way.

They have different chemical structures, different levels of stability, undergo different forms of processing and play different biological roles.

So perhaps the real question was never simply:

“Are fats harmful?”

A more useful question is:

What kinds of fats are we consuming, in what form, in what amount and within what metabolic environment will the body use them?

Maybe the problem was never fat as a nutrient category.

Maybe the problem was that, for too long, we treated all fats as if they were the same.

The Body Does Not Simply Consume Fat. It Is Built from It.

Fat is not just a source of calories.

It is also structural material.

Cell membranes are made largely from lipids. The brain is one of the most lipid-rich organs in the human body. The myelin sheaths that insulate nerve fibres also depend on lipid structures.

Cholesterol, meanwhile, is involved in the production of steroid hormones, while dietary fat is necessary for the normal absorption of the fat-soluble vitamins A, D, E and K.

Certain fatty acids are also used to create numerous signalling molecules involved both in inflammatory processes and in their normal resolution.

This is why the question:

“Are fats healthy?”

tells us very little on its own.

A more meaningful question is:

“What kind of material are we giving the body to build and regulate its own systems?”

Saturated, Monounsaturated and Polyunsaturated Does Not Simply Mean “Bad, Good and Bad”

The differences between fats begin at the level of their chemical structure.

Saturated fatty acids contain no double bonds and are therefore relatively stable.

Monounsaturated fats contain one double bond.

Polyunsaturated fats contain several.

These double bonds are important for the properties and functions of fats in the body, including the characteristics of cell membranes. At the same time, they also make the molecules more vulnerable to oxidation.

That is why looking only at the total number of grams of fat in a food does not tell us enough.

The whole chain matters:

type → source → processing → temperature → storage → balance.

A high-quality fat preserved within its natural food matrix and an industrial fat that has been repeatedly heated do not deliver the same nutritional message to the body.

Cholesterol Is Not Simply “Bad”

Few nutrition topics have been oversimplified as much as cholesterol.

Yet cholesterol is an essential molecule.

The body uses it as part of cell membranes, for the production of bile acids and as a precursor for steroid hormone synthesis. The body also produces a significant proportion of the cholesterol it needs on its own.

This does not mean that LDL is irrelevant.

And it certainly does not mean that very high LDL levels should be ignored.

It means something different:

Cardiovascular risk cannot be understood from total cholesterol alone.

To see the broader picture, we also need to consider triglycerides, HDL, ApoB, glucose control, metabolic health, the inflammatory environment, blood pressure, body composition and lifestyle.

Once again, the principle is the same:

We look at the system, not at one isolated number.

Omega-3 and Omega-6: It Is Not About Which One Is “Good”, but About Balance

Both omega-3 and omega-6 fatty acids are necessary for the body.

That is why it makes little sense to present one as “good” and the other as “toxic”.

Omega-6 fatty acids are not automatically harmful.

Omega-3s are not magical anti-inflammatory agents either.

What matters more is the balance between them, their sources and the overall nutritional environment.

EPA and DHA, obtained primarily from marine sources, are incorporated into cell membranes and act as precursors for specialised mediators involved in the normal resolution of inflammatory processes.

DHA is particularly important for the structure and function of the brain and nervous system.

There is, however, an important detail.

The plant-based omega-3 fatty acid ALA first needs to be converted into EPA and DHA, and this conversion is limited in humans.

This means that consuming ALA-rich seeds is not physiologically identical to obtaining EPA and DHA from oily fish or, when appropriate, from high-quality marine or algal sources.

The statement:

“I eat seeds, so I must be getting enough omega-3”

does not always tell the whole story.

The Brain Needs Fat – but the Type Matters

The brain is exceptionally rich in lipids.

For neurons to function properly, their cell membranes need to be both sufficiently stable and sufficiently fluid.

This matters for receptors, synapses and the signalling mechanisms through which nerve cells communicate.

DHA is an important part of this architecture.

And here, the Agaia logic is simple:

The quality of the incoming material matters for the quality of the structures the body builds from it.

We cannot consistently restrict essential structural components and simultaneously expect the body to have optimal conditions for building and maintaining the nervous system.

Fat Also Matters for Hormonal Function

Cholesterol is a precursor for steroid hormones.

These include testosterone, oestrogens, progesterone, cortisol and other molecules.

Of course, this does not mean:

“Eat more fat and you will produce more hormones.”

Human biology does not work that directly.

But chronically and aggressively restricting fat – particularly when combined with low energy intake, high training loads and insufficient recovery – may create an environment in which normal hormonal function becomes more difficult to maintain.

Again, the same sequence appears:

availability of raw materials → energy status → physiological signal → function.

It is not one nutrient in isolation, but the entire environment that determines the final outcome.

Bile Also Needs a Physiological Signal

Eating fat stimulates the release of the hormone cholecystokinin – CCK.

CCK contributes to contraction of the gallbladder and the release of bile, which is needed for normal fat digestion and absorption.

This is another useful example of a principle we frequently use at Agaia:

The body maintains function through use and signalling.

When a particular physiological stimulus is consistently removed, it may affect the way the related system functions.

Nutrition is therefore not merely a delivery system for calories.

It is also information.

Which Fats Do We Prefer?

The choice does not need to be overly complicated.

A strong foundation can come from foods and sources such as:

• extra virgin olive oil;
• oily fish;
• avocado;
• nuts and seeds;
• eggs;
• high-quality full-fat dairy products when well tolerated;
• reasonable amounts of naturally occurring animal fats as part of minimally processed foods.

Extra virgin olive oil deserves particular attention not only because of its oleic acid content.

High-quality olive oil also contains a range of polyphenols – one of the features that makes the Mediterranean dietary pattern so interesting from a cardiovascular and metabolic health perspective.

Once again, this shows why a fat cannot be judged solely by the number of grams it contains.

The entire food matrix matters.

Which Fats and Processing Methods Should We Limit?

Instead of demonising a particular plant or one specific fatty acid, we believe it makes more sense to focus on processing, temperature and oxidation.

Fats can oxidise.

This becomes particularly relevant when certain oils are repeatedly exposed to high temperatures, oxygen and light.

That is why one of the least desirable combinations is:

refined fat + high heat + repeated heating + ultra-processed food.

A typical example is the industrial deep fryer.

The same oil may be heated again and again, while lipid oxidation products gradually accumulate.

At that point, the relevant question is no longer just:

“How many calories are in this fried food?”

A better question is:

“What kind of chemical material are we providing to the body?”

This Is the Difference Between Real Food and Food Technology

An olive can become olive oil.

Oily fish provides EPA and DHA together with protein and other nutrients.

An egg contains fat, choline, protein and a range of micronutrients.

Avocado provides monounsaturated fat alongside fibre and phytonutrients.

These are examples of food matrices, where different components naturally exist together.

Now compare them with an ultra-processed product made from refined starches, sugars, emulsifiers and technologically processed fats.

The two foods may even contain a similar number of calories.

But:

Equal calories do not mean an equal biological message.

This is where the distinction between real food and food technology becomes especially important.

This Is Why We Do Not Simply Count Grams of Fat

Just as counting calories alone is not enough, looking only at total fat intake is not enough either.

We want to know more.

What is the source?

How has it been processed?

At what temperature was it prepared?

What other nutrients are present alongside the fat?

How well is it digested?

What are the individual needs of the person?

How well is their digestive system functioning?

What is their metabolic environment?

These questions matter because a person with impaired bile function, an athlete with a high energy expenditure and someone with severe insulin resistance should not automatically receive the same nutritional strategy.

Context determines the need.

The Big Mistake Was Not That We Ate Fat

One of the major mistakes was trying for years to reduce nutrition to a simple formula:

fat = bad

low-fat = good

But when fat was removed from many industrial food products, taste and texture still had to be restored somehow.

Often, this meant adding more refined carbohydrates, sugars, starches and other highly processed ingredients.

The result was an enormous range of products labelled “low-fat”.

But:

A low-fat product is not automatically a high-quality food.

Removing one ingredient does not improve a food if it is simply replaced by another unfavourable combination.

Fat Is Not the Enemy

Fat is energy.

But it is much more than energy.

It is structure.

A signal.

A raw material.

Part of our cell membranes.

Part of the nervous system.

A contributor to hormonal physiology.

Necessary for the absorption of certain vitamins and involved in normal digestive function.

None of this means that all fats are equal or that quantity does not matter.

That is why the question should not be:

“Should I eat fat?”

The better questions are:

What kind of fat?

How much?

From what source?

How has it been processed and stored?

And within what metabolic environment will my body use it?

Because in nutrition, extremes rarely provide the best answer.

Context matters more.

We do not need to be afraid of fat.

We need to learn how to distinguish real food from its highly processed industrial substitute.

That is where a more informed choice begins.