For many years, people were told that eating less fat was the key to a healthy diet.
Today, nutritional guidance focuses more on the type of fat you eat, not simply the total amount.
Some fats are important for normal body function and can support cardiovascular health. Others, particularly industrially produced trans fats, should be avoided as much as possible.
So which fats should you choose?
Why Does Your Body Need Fat?
Dietary fat provides energy and helps the body absorb vitamins A, D, E and K.
It also supplies essential fatty acids that the body cannot produce on its own.
Fat is therefore a necessary part of a balanced diet.
The goal is not to eliminate fat, but to choose appropriate sources and amounts.
What Are the Main Types of Dietary Fat?
Dietary fats are commonly divided into three main groups.
Unsaturated fats are generally the preferred fats for cardiovascular health. They are found in olive oil, rapeseed oil, nuts, seeds, avocados and fish.
Saturated fats are found in foods such as butter, fatty meat, cream, cheese, coconut oil and palm oil.
Trans fats may occur naturally in small amounts in some animal foods, but industrially produced trans fats are particularly harmful to cardiovascular health.
The health effects of foods depend on the overall dietary pattern and what replaces them.
Which Fats Are Best for Your Heart?
Unsaturated fats are generally the best choice.
Particularly useful sources include:
* Extra virgin olive oil: Rich in monounsaturated fats and naturally occurring plant compounds. * Rapeseed oil: Provides unsaturated fats and is suitable for many everyday cooking methods. * Walnuts and almonds: Supply unsaturated fats, fibre and other nutrients. * Seeds: Flaxseeds, chia seeds and other seeds contribute beneficial fatty acids. * Oily fish: Salmon, sardines, herring and mackerel provide long-chain omega-3 fatty acids. * Avocados: Provide mainly monounsaturated fats and dietary fibre.
These foods can be incorporated into a balanced diet without needing to follow a complicated nutritional programme.
Is Olive Oil Better Than Butter?
For cardiovascular health, replacing butter with olive oil or other oils rich in unsaturated fats is generally a favourable choice.
Butter contains a relatively high proportion of saturated fat.
Olive oil contains predominantly monounsaturated fat.
Replacing saturated fats with unsaturated fats can help reduce LDL cholesterol, a major causal risk factor for atherosclerotic cardiovascular disease.
This does not mean that a small amount of butter is automatically harmful.
The important question is what you eat regularly and which fats make up most of your diet.
What Does WHO Recommend About Fat Intake?
The World Health Organization recommends that adults obtain at least 15% of their daily energy from fat.
For adults, limiting total fat intake to 30% of daily energy or less may help prevent unhealthy weight gain at the population level.
WHO also recommends:
* Saturated fat: No more than 10% of total daily energy. * Trans fat: No more than 1% of total daily energy. * Industrial trans fats: Avoid them as much as possible.
For a diet providing 2,000 calories daily, 10% of energy from saturated fat corresponds to approximately 22 grams.
These are general recommendations, not personalized medical prescriptions.
Is Coconut Oil a Healthy Fat?
Coconut oil is often marketed as a natural or particularly healthy alternative.
However, it contains a high proportion of saturated fat.
Compared with oils rich in unsaturated fats, coconut oil generally produces less favourable effects on LDL cholesterol.
There is insufficient clinical evidence to recommend coconut oil over olive oil or rapeseed oil for cardiovascular protection.
Are Nuts Too High in Fat?
Nuts are energy-dense, but that does not make them unhealthy.
They provide unsaturated fats, protein, fibre, vitamins and minerals.
Regular nut consumption is associated with favourable cardiovascular outcomes as part of a balanced dietary pattern.
A small handful of unsalted nuts can be a useful everyday snack.
Portion size still matters, particularly when overall energy intake needs to be managed.
Do You Need Omega-3 Supplements?
Oily fish provides omega-3 fatty acids together with protein and other nutrients.
For most healthy adults, eating fish as part of a balanced diet is preferable to automatically taking supplements.
Omega-3 supplements have not consistently demonstrated cardiovascular benefits in otherwise healthy people.
Certain prescription omega-3 treatments may be appropriate for selected patients with specific cardiovascular risk profiles, but this is different from routine supplementation for longevity.
What Is the Simplest Way to Improve Your Fat Intake?
You do not need to count every gram of fat.
Start by making a few consistent substitutions.
Use olive oil or rapeseed oil instead of butter for many meals.
Choose nuts instead of highly processed snacks.
Include fish regularly if you eat it.
Limit processed meats and foods containing industrial trans fats.
These changes are more meaningful than focusing on whether a single food is labelled “low fat.”
Why Do Healthy Fats Matter for Aging?
Cardiovascular disease remains a major cause of illness and premature death.
Replacing saturated fats with unsaturated fats can improve blood cholesterol levels and support cardiovascular prevention.
Dietary patterns rich in unsaturated fats, vegetables, fruits, whole grains and legumes are associated with better long-term health outcomes.
However, no individual fat or oil has been proven to directly reverse biological aging.
Based on Research
World Health Organization. Healthy diet. January 2026. https://www.who.int/news-room/fact-sheets/detail/healthy-diet
World Health Organization. Saturated fatty acid and trans-fatty acid intake for adults and children: WHO guideline. 2023. https://www.who.int/publications/i/item/9789240073630
World Health Organization. Total fat intake for the prevention of unhealthy weight gain in adults and children: WHO guideline. 2023. https://www.who.int/publications/i/item/9789240073654
