Saturated Fat with Dr. Ben Bikman

The Great Fat Debate: Why Saturated Fat Isn’t The Villain You Think It Is

You might wonder: If saturated fat is bad for you, why are heart disease and diabetes skyrocketing while we eat less of it?.

For decades, we’ve been told that saturated fat—the kind found often in meat and dairy—is a metabolic menace, leading straight to high cholesterol and insulin resistance. But the real science suggests the truth is far more complex, and frankly, shocking. It turns out, how your body processes fat depends heavily on what else you’re eating.

Let’s dive into the powerful research challenging everything you thought you knew about saturated fat.

Meet the Myth Buster

Our guide through this complicated nutritional landscape is Dr. Ben Bikman, a respected biomedical scientist and professor of Cell Biology. Dr. Bikman doesn't just offer opinions; he has deep authority in this area, having focused extensively on lipids and metabolism during his PhD dissertation and his postdoctoral fellowship, including work with Duke Medical School.

Perhaps most importantly, Dr. Bikman actually authored some of the original research that anti-saturated fat advocates use against him. He had to challenge his own strongly held conviction that saturated fats were a problem by looking closer at the data.

The Scientific Truth (And Its Fatal Flaw)

The idea that saturated fat causes insulin resistance isn’t baseless; it started in respected laboratories.

How Fat Acts on the Cell

Dr. Bikman’s early work (2011) showed that saturated fats uniquely activate a specific cellular doorway called tllr4 (toll-like receptor 4). When tlr4 is triggered, it ramps up inflammation and causes your body to synthesize and collect fats called ceramides.

Here’s why this matters: Ceramides are known to be the main drivers of insulin resistance. They act like a dam, blocking the entire signaling waterfall (or "cascade") that happens after insulin binds to a cell, ultimately making the cell resistant to insulin.

The Critical Mismatch: Labs vs. Life

This data is accurate. But here is the massive catch that anti-fat advocates often miss: how were these results achieved?

The experiments involved either directly infusing saturated fats intravenously into the bloodstream or bathing cells in a culture dish with the fats.

Think about it this way: Directly pumping pure saturated fat into your veins is not the same thing as eating a steak.

When you eat fat, it goes through a complex journey: bile salts emulsify it; enzymes called lipase snip the fatty acids off; the fatty acids are absorbed by the intestinal wall, re-packaged into triglycerides, and then bundled into large protein complexes called chylomicrons. These massive complexes enter the slow-moving lymph system first, finally reaching the blood up near your chest cavity. This slow, multi-step digestive process suggests that eating saturated fat does not flood your system with raw fat in the same way as a direct infusion.

The Shocking Discoveries from Real-World Studies

When researchers started studying people actually eating saturated fat, the findings directly challenged the laboratory theory.

Surprising Fact 1: Eating Saturated Fat Doesn’t Raise Blood Saturated Fat

The most direct challenge to the old myth comes from the question: does eating more saturated fat increase the amount of saturated fat circulating in your blood (plasma)? Research suggests the answer is a resounding No.

A fascinating 2014 study by Volek et al. took participants through a stepwise increase in saturated fat intake, sometimes consuming two or three times the original amount. Even with these dramatic changes, their blood circulating saturated fat levels remained totally flat. In fact, the levels dropped with the onset of the low-carb diet and stayed low.

The body has powerful adaptations: it might burn the fat for fuel or even convert the saturated fat into other fats, like oleic acid (the main fat found in olive oil), before storage.

Surprising Fact 2: High Saturated Fat (With Low Carbs) Can Improve Insulin Resistance

If saturated fat causes insulin resistance, then high-fat diets should make people sicker. But that’s not what we see.

A 2020 meta-analysis by Choi et al., combining data from 14 randomized trials on overweight and Type 2 diabetic patients, found that high-fat ketogenic diets resulted in significant improvements in glycemic control and insulin resistance compared to low-fat diets. This is a direct refutation of the idea that high saturated fat causes metabolic harm when carbohydrates are restricted.

Even comparing different versions of the standard DASH Diet diet (a diet famous for being low-fat), one study found that the high-fat version (where people ate full-fat dairy liberally) achieved the exact same reduction in blood pressure. Crucially, this high-fat group also saw better improvements in blood lipids, including lower triglycerides and VLDL—metrics that are often more predictive of heart risk than LDL.

Surprising Fact 3: Carbs Can Cause Your Body to Make Its Own Saturated Fat

Perhaps the most counterintuitive finding: you can increase the saturated fat in your blood without eating any saturated fat at all.

When you eat excess carbohydrates, especially refined sugars and starches, the resulting surge in insulin activates a process in the liver called de novo lipogenesis (literally, "synthesis of new fat"). The liver then takes the carbons from the glucose and converts them directly into saturated fat, specifically palmitic acid, which it then packages and releases into the body via VLDL.

Studies by Acheson et al. (1988) and Sevastianova et al. (2012) confirmed that if your liver is full of stored energy and you keep eating carbs, the liver will convert that excess into saturated fats, increasing the levels circulating in your plasma.

The Real Danger Zone: Mixing Your Macros

While dietary saturated fat is fine when carbs are low, there is one metabolic scenario to avoid: High fat mixed with high carb.

This combination is a "particularly vicious metabolic mix". The high carbohydrates spike insulin (the signal to store energy), and the high fat provides the raw material for your fat cells to easily get bigger.

Some human studies, like one by Lukkoneen et al. (2018), suggest that if you are following a hypercaloric (overeating) high-carb diet, mixing it with saturated fat might result in worse insulin resistance than mixing that same high-carb, hypercaloric diet with unsaturated fat.

The Takeaway: If you keep your carbs low, saturated fat is burned for fuel. If you insist on a high-carb diet, overeating saturated fat on top of that may be especially problematic.