Saturated Fat and Dairy: Then and Now – How Science Has Moved Beyond Ancel Keys

In the 1960s and 70s, Ancel Keys’ diet-heart hypothesis cast saturated fat as the chief villain in our diets. Butter, cheese, full-fat milk, cream, and fatty meats were all branded as threats to heart health.

Fast forward to today, and the story is far more nuanced. Modern research still acknowledges that diet impacts cardiovascular health—but saturated fat’s role isn’t quite what Keys claimed. Let’s explore how the science has evolved.

The Old View: Saturated Fat as the Enemy

Keys’ work linked high saturated fat intake to high cholesterol, and high cholesterol to heart disease.

For decades, health authorities advised the public to replace saturated fats with polyunsaturated vegetable oils and to choose low-fat dairy over full-fat.

Supermarkets filled with “low-fat” yoghurts, margarines, and dairy alternatives. The underlying message:

Less fat = healthier heart.

The New Evidence

Over the past two decades, large-scale studies and meta-analyses have painted a more complex picture:

Not all saturated fats are equal

Saturated fats in processed meats don’t behave the same way in the body as those in dairy or dark chocolate.

Dairy has unique benefits

Fermented dairy products like yoghurt and cheese are linked with lower heart disease risk in several studies. They contain beneficial bacteria, calcium, and bioactive compounds that may counteract any negative cholesterol effects.

It’s what you replace saturated fat with that matters

Replacing saturated fat with refined carbohydrates (like white bread and sugary snacks) doesn’t reduce—and can even increase—heart disease risk. Replacing it with unsaturated fats from nuts, seeds, olive oil, and fish is where benefits show up.

The sugar factor

John Yudkin’s once-dismissed warnings about sugar have been vindicated. Diets high in added sugars, especially from ultra-processed foods, are now strongly linked with obesity, type 2 diabetes, and cardiovascular disease.

Modern Consensus

The latest UK and international dietary guidance no longer calls for an aggressive “low-fat at all costs” approach.

Instead, it recommends:

Balancing fat types – prioritising unsaturated fats, but not automatically fearing all saturated fats.

Eating whole foods – choosing minimally processed dairy, meats, and plant foods over ultra-processed options.

Looking at diet patterns – the Mediterranean and Nordic diets, which include dairy and moderate saturated fat, remain among the healthiest.

From Demonisation to Context

Where Keys’ era saw dairy fat as a universal danger, modern science takes a context-based view:

Cheese and yoghurt? Often beneficial.

Butter? Fine in moderation.

Ultra-processed cakes and biscuits made with palm oil and sugar? Best avoided, regardless of fat type.

Final Thoughts

We owe a lot to Ancel Keys for focusing the world’s attention on diet and heart health. But today’s evidence shows we can put full-fat dairy back on the table—provided it’s part of a balanced, whole-food diet.

The big takeaway? Nutrition science evolves. What was “bad” in the 1960s may, in the light of new evidence, turn out to be far more complicated—and sometimes even good for you.

Baked vs Fried Snacks: Which Is Better for You?

When it comes to choosing between baked and fried snacks, the decision is often framed around health versus indulgence. 

Fried snacks are known for their crispy texture and rich flavour, while baked options are marketed as the healthier alternative. 

But how much of that is really true? Let’s take a closer look at both options to determine which might be better for you, and when.

The Basics: What’s the Difference?

Fried snacks are cooked in hot oil, often at high temperatures. This includes crisps, chips, doughnuts, and pakoras. The oil not only cooks the food quickly but also adds significant calories and fat.

Baked snacks are cooked using dry heat in an oven, meaning little or no oil is used. Think baked crisps, puffed grain snacks, crackers, and certain cereal bars.

Nutritional Comparison

Category Fried Snacks Baked Snacks

Calories Generally higher due to oil Often lower, especially if oil-free

Fat High in saturated and trans fats Lower fat content overall

Crunch/Flavour Crispy, rich, often addictive. Can be drier but lighter

Shelf Life Shorter (unless heavily processed) Usually longer

Are Baked Snacks Healthier?

In many cases, yes. Baked snacks tend to have:

Lower total fat and fewer calories.

Less risk of containing trans fats, which are known to raise bad cholesterol and lower the good kind.

Less greasy residue and fewer empty calories.

However, not all baked snacks are created equal. Some are high in salt, sugar, or refined flour, and might not be much healthier than their fried counterparts.

But Don’t Dismiss Fried Snacks Entirely…

Fried snacks aren't inherently evil. In moderation, they can be part of a balanced diet. Homemade versions,like air-fried potato wedges or shallow-fried samosas—allow better control over oil type and quantity.

Also, some nutrients, like fat-soluble vitamins, are better absorbed with fat. A small amount of healthy fat (like olive or rapeseed oil) in cooking isn't always a bad thing.

Baking Innovations: The Rise of Air-Frying

Air fryers have revolutionised home cooking, offering a middle ground. They “fry” food with hot air and minimal oil, giving that crisp texture without the grease. It’s a popular way to enjoy chips or battered treats with significantly reduced fat.

So, Which Is Better?

For everyday snacking:

Baked snacks are generally the better choice, especially those with whole grains, seeds, or legumes and minimal additives.

For occasional indulgence:

Fried snacks can have a place, just aim for smaller portions and choose healthier oils when cooking at home.

Top Tips for Smarter Snacking

Check nutrition labels—don’t be fooled by “baked” alone.

Watch out for salt and sugar levels in both varieties.

Opt for snacks with fibre and protein to feel fuller for longer.

DIY your own snacks when possible, oven-roast chickpeas or make kale crisps for a healthy crunch.

Final Thoughts

The choice between baked and fried snacks doesn’t have to be black and white. It’s all about balance, awareness, and quality. Baked snacks often win on the health front, but an occasional fried treat, especially one you’ve made yourself, is nothing to feel guilty about.

What’s your go-to snack? Baked or fried? Let us know in the comments below!