"Every successful diet in history restricts sugar. Sugar is, bar none, the most successful food additive known to man." Dr Robert Lustig, internationally renowned pediatric endocrinologist and author of Fat Chance: The Hidden Truth About Sugar, Obesity and Disease.

"Your LDL cholesterol is a little high."

For many people, those six words are enough to trigger worry.

Should you stop eating eggs?

Is butter now off the shopping list?

Have you increased your risk of a heart attack or stroke?

For decades we've been encouraged to think of LDL as "bad cholesterol" that should simply be kept as low as possible. But over the last twenty years, researchers have discovered that the picture is much more complex than that.

It turns out that not all LDL cholesterol behaves in the same way.

Understanding this difference won't just help you make sense of your blood test results. It can also help you focus on the lifestyle changes that really matter for protecting both your heart and your brain.

LDL cholesterol isn't just one thing

Imagine LDL particles as vehicles travelling along a motorway carrying cholesterol to different parts of your body.

Some are large, light and buoyant.

Others are much smaller and denser.

Although both carry cholesterol, they don't behave in exactly the same way.

Large, buoyant LDL

These particles are larger and less likely to become trapped within the lining of blood vessels. They are also less susceptible to oxidation - a chemical process that makes LDL more damaging to the artery wall.

Small, dense LDL

These particles are much smaller, allowing them to slip more easily into tiny defects within the lining of arteries.

Once there, they are more likely to become oxidised, triggering inflammation and contributing to the formation of plaque.

Research consistently shows that higher levels of small, dense LDL particles are more strongly associated with cardiovascular disease than larger, more buoyant LDL particles.

In other words, two people with exactly the same LDL cholesterol level may have very different levels of risk depending on the type of LDL particles they have.

What influences the type of LDL you produce?

This is where things become particularly interesting.

Many people assume that eating fat simply raises LDL cholesterol and therefore increases risk.

The reality is much more nuanced.

Saturated fat

Saturated fat has been one of the most debated topics in nutrition.

Current research suggests that while saturated fat can increase LDL cholesterol in some people, it often increases the larger, more buoyant LDL particles rather than the smaller, denser variety. It may also increase HDL ("good") cholesterol.

Scientists continue to debate exactly how saturated fat influences cardiovascular disease because the effect appears to depend on the individual, the foods being eaten and the overall quality of the diet.

In other words, butter on top of a diet full of vegetables, beans and whole foods may have a very different effect from butter eaten alongside a highly processed diet rich in sugar and refined carbohydrates.

Sugar, refined carbohydrates and excess fructose

A growing body of evidence suggests that diets high in added sugars and refined carbohydrates can have a very different effect.

These foods encourage the liver to produce more triglycerides, promote insulin resistance and increase the production of the smaller, denser LDL particles that are more strongly linked with cardiovascular disease.

Fructose deserves a special mention.

Unlike glucose, which can be used by almost every cell in the body, fructose is processed almost entirely by the liver.

When consumed in the small amounts naturally found in whole fruit, this isn't usually a problem. Fruit also provides fibre, vitamins, minerals and protective plant compounds that support health.

The concern comes from large amounts of fructose found in sugary drinks, sweets, desserts and many ultra-processed foods.

Over time, excessive fructose intake can contribute to fatty liver, elevated triglycerides, insulin resistance and an increase in small, dense LDL particles.

Rather than fearing an apple or a handful of berries, it's the regular intake of sugar-sweetened foods and drinks that deserves our attention.

Cholesterol isn't the whole story

One of the biggest misconceptions is that cholesterol alone causes arteries to become blocked.

The process is much more complex.

Healthy arteries have a smooth inner lining.

When that lining becomes damaged - through factors such as chronic inflammation, smoking, high blood pressure, insulin resistance or oxidised LDL - the body begins a repair process.

Cholesterol becomes part of that repair process.

If inflammation continues over many years, plaque gradually develops and arteries can become narrower and less flexible.

This helps explain why someone with only moderately raised cholesterol may develop heart disease, while someone with higher cholesterol may remain healthy for decades.

It's the combination of inflammation, metabolic health, blood pressure, blood sugar, smoking, exercise, sleep and diet that determines overall risk.

Two powerful ways to improve your metabolic health

The encouraging news is that you can influence many of these processes.

Two of the most effective strategies are surprisingly simple.

1. Eat more fibre

Fibre does far more than support digestion. It helps remove cholesterol from the body by binding bile acids in the digestive system. It feeds the beneficial bacteria living in your gut. It improves blood sugar control. It reduces inflammation. And it helps keep you fuller for longer.

Good sources include:

• Oats

• Beans

• Lentils

• Chickpeas

• Apples

• Pears

• Berries

• Chia seeds

• Ground flaxseed

• Vegetables

Aim for at least 30 grams of fibre each day.

Most adults currently eat only around half that amount.

2. Move your body regularly

Exercise changes far more than the number of calories you burn.

Regular physical activity helps your muscles become more sensitive to insulin, lowers triglycerides, raises HDL cholesterol, reduces inflammation and improves overall metabolic health.

It doesn't have to involve running marathons. Try:

• A brisk walk.

• Cycling.

• Swimming.

• Gardening.

• Resistance exercises.

They all help.

Consistency matters far more than perfection.

5 practical ways to get started this week

If you're wondering where to begin, keep it simple.

1. Add one high-fibre food to every meal.

Think oats at breakfast, lentils in soup, beans in salads or extra vegetables with dinner.

2. Swap refined carbohydrates for whole-food alternatives.

Choose porridge instead of sugary cereal, wholegrain bread instead of white and potatoes with their skins rather than highly processed snacks.

3. Cut back on sugary drinks.

Replacing fizzy drinks or fruit juice with water or sparkling water is one of the quickest ways to reduce excess sugar and fructose intake.

4. Aim to move every day.

Even a 20-30 minute brisk walk after a meal can improve blood sugar control.

5. Think beyond one cholesterol number.

Blood pressure.

Waist circumference.

Blood sugar.

Sleep.

Stress.

Physical activity.

They all work together to influence the health of your heart and your brain.

The bottom line

For many years we've been encouraged to fear a single cholesterol number.

Today's research paints a more complete picture.

Your lifestyle doesn't simply influence how much cholesterol you carry - it influences the type of LDL particles your body produces, your levels of inflammation, your insulin sensitivity and the long-term health of your arteries.

That's empowering.

Rather than focusing on one number in isolation, focus on building habits that support your whole metabolism.

Small daily choices, like prioritising fibre and limiting foods and drinks high in added sugar, won't just support healthy cholesterol - they'll help protect your heart, your brain and your ability to stay active, healthy and mentally sharp for many years to come.