Saturated Fat: The 60-Year-Old Argument Revisited
The ketogenic diet has reignited debates about saturated fat that began in the 1960s. For decades, public health guidance warned against butter, cheese, and red meat—foods now central to many keto meal plans. The current evidence suggests a more nuanced picture, particularly when viewed through the lens of carbohydrate restriction.
What the studies actually show
Research from the past two decades challenges old assumptions. A 2017 review in Nutrients analysed 43 studies on ketogenic diets and cardiovascular risk factors. It found that while LDL cholesterol sometimes rises with increased saturated fat intake, this often coincides with improvements in triglycerides, HDL, and insulin sensitivity—markers that better predict heart disease risk (Kosinski & Jornayvaz, 2017).
Meanwhile, a 2008 study in Lipids compared low-fat and low-carb approaches for metabolic syndrome. Participants eating more saturated fat on a carb-restricted diet saw greater improvements in blood pressure and lipid profiles than those on a low-fat regimen (Volek et al., 2008).
The insulin resistance factor
Saturated fat behaves differently in metabolically healthy individuals versus those with insulin resistance. The keto adaptation timeline matters—as the body shifts to fat burning, lipid metabolism becomes more efficient. This may explain why some studies show neutral or even beneficial effects of saturated fat in low-carb contexts.
What this means in practice
UK shoppers can find quality saturated fats without breaking the bank. Tesco sells 250g blocks of grass-fed butter for £1.90, while Aldi’s Specially Selected mature cheddar costs £2.19 for 400g. During colder months, these become staple ingredients for keto-friendly soups and roasts.
Frequently asked questions
Does saturated fat cause heart disease?
The relationship appears more complex than once thought. In isolation, no single nutrient determines cardiovascular outcomes. Dietary patterns, insulin status, and individual genetics all play roles.
Should I avoid coconut oil?
Coconut oil is predominantly saturated fat, but its medium-chain triglycerides may have distinct metabolic effects. Many keto practitioners use it judiciously for cooking.
How much is too much?
There’s no universal threshold. Those with familial hypercholesterolemia or specific ApoE genotypes may need to moderate intake, while others tolerate higher amounts.
The bottom line
The saturated fat debate continues because nutrition science evolves. Current evidence suggests its effects depend heavily on dietary context and individual factors. For those following a ketogenic diet, focusing on whole food sources and monitoring blood markers makes more sense than rigid avoidance. If you’d rather not do the macro maths yourself, the Keto Dieting app does it for you on Google Play and the App Store.
References
- Kosinski C, Jornayvaz FR (2017). Effects of Ketogenic Diets on Cardiovascular Risk Factors: Evidence from Animal and Human Studies. Nutrients. https://doi.org/10.3390/nu9050517
- Volek JS, Phinney SD, Forsythe CE, et al. (2008). Carbohydrate restriction has a more favorable impact on the metabolic syndrome than a low fat diet. Lipids. https://doi.org/10.1007/s11745-008-3274-2
