Have you spent years thinking that fat is bad for you?
Do you always choose the ‘low fat’ or ‘fat-free’ options because you’ve been told they’re healthier? Well they’re not. In fact, most of us probably aren’t eating enough fat.
Just like protein and carbohydrates, fat is another category of macronutrient and our body needs it to function well. Fat can actually help you lose weight, protect against heart disease, absorb vitamins and support your immune system.
You just need to know which fats to eat and which to avoid.
These are the ones with the worst reputation. They're found in animal products like meat, egg yolks, cheese, cream and butter and in coconut oil.
For decades we’ve been told that eating saturated fat raises cholesterol, clogs your arteries and causes heart disease. It turns out that the research, on which this message was based, lacked any solid evidence. Saturated fat is not the culprit here and it doesn’t raise cholesterol, however it’s still best consumed in moderation.
These are the kinds of fats associated with the Mediterranean diet – particularly avocados and olive oil – and populations that eat a lot of these fats have some of the lowest rates of heart disease in the world. Many cardiologists advocate the Mediterranean diet as higher intakes of this kind of fat are linked to lower cholesterol levels (or, to be more accurate, a better ratio of LDL to HDL cholesterol).
You will probably know these as omega-3 and omega-6 – the essential fatty acids. ‘Essential’ relates to the fact that the body cannot make them; you need to eat them as part of your diet – or take as a supplement.
They fulfil many roles in the body, and sufficient levels have implications for cell membranes, hormones (they regulate insulin function), arthritis and joint pain, inflammation and immunity, depression, mood and memory.
As a rule, omega-3 fats are anti-inflammatory and omega-6 fats are pro-inflammatory. That’s not to say that omega-6 fats are inherently bad – inflammation is an essential part of our immune response – but we need to achieve the right balance between omega-6 and omega-3.
Historically, humans ate a good ratio of omega-6 to 3 – ranging between 1:1 and 4:1. The modern Western diet, packed with processed foods, vegetable oils and conventionally raised (rather than grass-fed) meat has shifted the ratio to around 20:1. When the ratio is so heavily weighted towards omega-6 it can lead to an increased risk of:
- Inflammatory conditions
- Autoimmune disease
- Heart disease
- Diabetes (type 2)
- High cholesterol
Why is fat so essential?
- Concentrated energy source. Gram for gram, fat is twice as efficient as carbohydrates in energy production. Fat is the preferred fuel for muscles and the heart. The brain can also burn fat for fuel.
- Energy store. Excess fat is stored for future energy production (excess calorific intake).
- Protection. Internal (visceral) fat protects your internal organs, like the kidneys and spleen.
- Insulation. ‘Subcutaneous adipose tissue’ (that’s the fat that you can feel by pinching your skin) helps to maintain normal body temperature and provides padding.
- Transport. Every cell membrane in your body is made of fat, and healthy cells allow efficient transportation of nutrients.
- Brain health. The brain is 60% fat.
- Hormone health. Many hormones are made from fat. These are known as steroid hormones and they govern stress, sex, and immune function.
- Fats regulate inflammation, mood and nerve function.
- Essential fatty acids are required for healthy skin, healthy cell membranes, healthy nerves, healthy joints and to help with absorption of fat-soluble vitamins A, D, E and K.
Fats are actually essential for survival (experiments on rats in the 1920s showed that, when fat was removed from the diet they died).
How did fat get such a bad name?
There’s no denying it - fat has got a bad reputation. Over the last 70 years low-fat products have been marketed as the saviour of our health. And the message from governments and the media was – and largely still is – eating fat leads to weight gain, raises cholesterol and puts us at greater risk of heart disease.
Part of the problem is that we use the same word for the fat we DON’T want (on the hips, around the middle and so on) and the fat we eat.
The demonisation of fat began in the 1950s when the American scientist, Ancel Keys, produced the first ‘evidence’ linking saturated fat to heart disease. He based his scientific opinion on observational data of heart disease, death rates and fat consumption in The Seven Countries Study, and assumed a correlation. There has been much criticism of Keys’ methodology, including reports of cherry picking the data - excluding data from 15 countries and only choosing others to fit his hypothesis. As an aside, when another scientist looked at the same research, but considered the data from ALL 22 countries, no correlation was found.
Governments and health care agencies across the world began advocating a low-fat-high-carb diet. They told us to fill up on bread, rice, cereals and pasta, and opt for low-fat or no-fat alternatives wherever we could.
But there are some fats you should avoid
Trans fats have been identified as one of the most harmful food ingredients. Small amounts of naturally occurring trans fats are found in animal products but it’s the artificial ones that are dangerous. These are cooking oils that have been chemically altered (hydrogenated) so that they become solid at room temperature. They are used in processed and fast foods and high-carb baked goods like cakes, biscuits and bread, and also in margarine or spreads.
They cause cell membranes to become stiff and hard so they can no longer function correctly and they have been shown to raise ‘bad’ LDL cholesterol and reduce the ‘good’ HDL cholesterol.
Refined vegetable oils are also problematic. They are easily damaged and oxidised by heating and processing, making them highly inflammatory. They are cheap to produce and are therefore used in most processed foods.
Say no to ‘low-fat’
Of course the food industry saw an opportunity to create products to fit the ‘fat is bad’ advice. And here’s why you should absolutely NOT go down the low- / no-fat route…
Fat is replaced by sugar
The biggest problem is that when you remove the fat from foods, you need to replace it with something else to make those foods palatable – and that is usually sugar or artificial sweeteners or flavourings. We now know that sugar is linked to obesity, type 2 diabetes and high cholesterol.
Highly processed oils
Ironically, these so called ‘heart healthy’ vegetable oils, like margarine, are used to replace saturated fat but they are actually MORE harmful to cardiovascular health and should be avoided.
Low fat = high carb
Inevitably when you go low-fat, you increase your carb intake. A carb-rich meal will create a spike in your blood sugar and trigger the release of insulin – the fat storage hormone. Then your blood sugar levels will crash and you’ll have another carb-craving a couple of hours later – probably something processed and high in ‘bad’ fats.
Enjoy these fats
Avocados – high in healthy monounsaturated fats, fibre and vitamin E
Coconut oil – apart from helping reduce bad cholesterol and blood pressure, coconut oil is an anti-fungal (caprylic acid) when used both externally and internally. Good for cooking and baking
Nuts and seeds – packed with essential fatty acids and nutrients like magnesium and vitamin E
Oily fish – rich in omega-3 fatty acids for heart and brain health, and essential for hormone balance
Olive oil – high in monounsaturated fats and antioxidants to fight inflammation
Organic grass-fed and free-range meat, poultry and eggs - higher levels of omega-3 fatty acids versus grain-fed equivalents.
What to cook with
Many of the problems of oils and fats in the diet stem from the way they are obtained, processed and used. Cooking or frying some fats at high temperature leads to oxidation and the production of free radicals, which are highly inflammatory for the body and may increase the risk of heart disease or cancer.
Use these oils for cooking:
Coconut oil, butter, ghee, goose/duck fat, cold-pressed rapeseed oil
Use these oils for low heat cooking or for dressings:
Olive oil, avocado oil, flaxseed oil (for dressings, do not heat)
What to avoid
Processed foods, ready meals, fast foods, fried foods, crisps, biscuits, snacks, low-/no fat foods, margarines and spreads, vegetable oils (sunflower, canola, soy).
How to add more healthy fats to your diet
Eating a diet rich in whole, unprocessed foods packed with colourful fruits, vegetables, nuts, seeds and beans and a good quality source of protein, will ensure you are mainly eating the healthy fats and limiting the ‘bad’ ones.