Where Does the Fat in Your Ribeye Really Go?

# You Just Ate a Ribeye: Where Does All That Fat Actually Go?

**by Laurent Glatz – for Athletic Carnivore**

You’ve just finished a beautifully marbled ribeye. It contained proteins, but also several dozen grams of fat.

And often, a very simple image comes to mind: this fat passes through the intestine, enters the bloodstream, circulates through the arteries, and eventually "sticks" to their walls.

The problem is that **the human body absolutely does not work like a sink into which fat has been poured.**

Between the fat in your ribeye and the fat your muscles will burn, the fat your adipose tissue can store, or the fat your liver will reclaim, there is a true biological logistics chain.

And it’s fascinating.

First Step: Your Ribeye Must Be Broken Down

Most of the fat in a ribeye exists as **triglycerides**.

Imagine a small tripod: a glycerol molecule attached to three fatty acids.

The problem is that fats and water don’t mix.

Your intestine contains a lot of water. Putting a large fat globule in there is like pouring oil into a glass of water: it forms large droplets that digestive enzymes would struggle to attack.

Your body uses a clever trick.

Bile acts somewhat like dish soap on a greasy pan: **it breaks down large fat droplets into much smaller structures**, greatly increasing the surface area accessible to digestive enzymes.

Next comes mainly pancreatic lipase.

Now imagine molecular scissors.

They cut triglycerides to produce fatty acids and monoacylglycerols. These products can then be transported close to the intestinal wall thanks to small structures containing bile salts: micelles.

First surprise: **the triglyceride from your steak generally does not enter your bloodstream intact.**

It is first dismantled.

But the story gets even more astonishing.

The Intestine Breaks It Down… Then Rebuilds It

The digestion products enter the cells lining your small intestine: the **enterocytes**.

And here, the body does something that might seem completely absurd.

It just broke down the triglycerides…

and then rebuilds them.

Long-chain fatty acids and monoacylglycerols are reassembled inside the enterocyte to reform triglycerides.

Why go through all this trouble?

Because a triglyceride is hydrophobic. It cannot simply be released freely into blood, which is mostly water.

So it needs a transport vehicle.

This vehicle is called the **chylomicron**.

The Chylomicron: The Truck Carrying Your Ribeye Fat

Imagine a huge transport ball.

Inside: mainly triglycerides.

Around it: a shell made up of phospholipids, cholesterol, and specialized proteins called apolipoproteins.

One of these is particularly important: **ApoB48**.

Think of it as the truck’s chassis. Without this chassis, it’s impossible to properly build the vehicle designed to transport dietary lipids.

And now comes something many people completely overlook.

The large chylomicron does not go directly from the intestine to the liver via the portal vein like many other nutrients.

It’s too bulky to take this usual route.

Instead, it enters tiny lymphatic vessels located at the center of the intestinal villi, called **lacteals** or *chyliferous vessels*.

In other words, a large portion of the long-chain fat from your ribeye begins its blood journey… **by first passing through the lymphatic system**.

The chylomicrons then travel up the lymph, reach the thoracic duct, and finally join the venous circulation near the left subclavian vein.

Your ribeye fat has now truly entered the systemic circulation.

But the fat is still not free.

It travels inside its trucks.

Second Step: The Trucks Arrive at the Unloading Docks

The chylomicron now circulates in the blood carrying its cargo of triglycerides.

But how does a muscle retrieve this energy?

On the inner surface of certain capillaries, there is a crucial enzyme: **lipoprotein lipase**, or LPL.

Imagine a logistics center located beside a highway.

The chylomicron arrives fully loaded.

LPL gradually opens its triglycerides and releases fatty acids.

These fatty acids can then be taken up by nearby tissues.

In muscle, they can enter pathways to produce energy.

In adipose tissue, they can be reassembled and stored for later use.

The heart, skeletal muscles, and adipose tissue are major sites where this LPL system is especially important.

The chylomicron is thus progressively emptied.

Imagine a semi-trailer leaving a warehouse with 30 tons of goods and stopping in several cities along the way.

At each stop, it unloads part of its cargo.

By the end of the journey, it’s no longer the huge truck it was at the start.

It becomes what is called a **chylomicron remnant**.

And this remnant eventually returns to the liver.

The Liver Reclaims What’s Left

After delivering most of its triglycerides, the remnant still contains various lipids, cholesterol, and ApoB48.

It also carries ApoE, which helps the liver recognize it.

The liver then takes up these remnants via several receptor systems.

The simplified circuit is therefore:

**ribeye → digestion → enterocyte → chylomicron → lymph → blood → muscles/adipose tissue → remnant → liver.**

Already, this is far from:

**"I eat fat → fat enters my arteries → it clogs my arteries."**

But beware of making the opposite mistake.

No, This Does Not Mean All Dietary Fats Are Automatically Harmless for Cardiovascular Health

This is where biology gets interesting.

The large triglyceride-rich chylomicron at the start of the journey is not simply a gigantic LDL particle.

Chylomicrons are produced by the intestine and carry ApoB48.

VLDL particles are mainly produced by the liver and carry ApoB100. Some VLDL are gradually converted into IDL and then LDL.

**The LDL that appears on your blood test is therefore not simply “the fat from your steak that ended up in your blood.”**

But some triglyceride-rich lipoprotein remnants can become small enough and cholesterol-rich enough to penetrate the arterial wall when they accumulate.

Current data consider these residual particles potentially atherogenic.

So the correct conclusion is neither:

"Eating fat directly clogs arteries,"

nor:

"Since chylomicrons are physiological, all blood lipids are irrelevant."

Both views are too simplistic.

And This Is Where Your Individual Metabolic Terrain Starts to Matter

Two people can eat exactly the same ribeye.

On paper: same proteins, same triglycerides, same fatty acids.

Yet their metabolic responses can differ.

Their physical activity levels differ.

Their muscle mass differs.

Their insulin sensitivity differs.

Their fasting triglyceride levels differ.

Their livers do not necessarily produce the same amount of VLDL.

Their ability to clear triglyceride-rich lipoproteins is not necessarily identical.

Their genetics can also modify some elements of the system.

That’s why looking only at what’s on the plate is not always enough.

**The real issue is also what your body does with what you just ate.**

This is especially true in a carnivore or very low-carb diet where the energy contribution from fats can become much higher.

Eating more fat means relying more on this logistics system.

But that alone does not predict whether this system works perfectly for you.

For one person, traffic may flow smoothly: trucks arrive, unload quickly, and remnants disappear.

For another, the metabolic highway may be much more congested.

This is precisely the difference between looking at **a food** and looking at **an organism**.

You can spend months debating whether butter is good or bad, whether ribeye is too fatty, whether saturated fat is dangerous, or whether your LDL should worry you.

But if you don’t understand how your diet, triglycerides, HDL, LDL, ApoB when available, physical activity, metabolic state, and time evolution all interact, you risk seeking answers in a food when the real answer lies in **how your body manages the traffic.**

At this point, the real question is no longer just: **"How much fat am I eating?"**

It becomes:

**"What is my body actually doing with this fat?"**

And if this question remains unclear despite everything you’ve read about carnivore diets, cholesterol, or fats, piling on another generic piece of advice may change nothing.

The most useful approach is to put the various signals into context to understand your own metabolic terrain.

**Is it really the fat on your plate you should be watching… or the way your body transports, uses, and eliminates it?**

**Understanding My Metabolic Terrain**

#CarnivoreDiet #Carnivore #Nutrition #HumanBiology #Metabolism #Triglycerides #Chylomicrons #Cholesterol #LDL #Fats #MetabolicHealth #AthleticCarnivore