I often see in clinic lots of confusion around fats with people worrying about how much they should be eating and whilst it’s true that 1g of fat contains over twice as many calories as 1g of either protein or carbohydrates, it’s also true that not all fats are equal and some are actually incredibly beneficial.
Dietary fat is essential in the mechanics of the human body as it….
- makes up the cell walls of every one of the trillions of cells that form us
- protects our internal organs
- is programmed to be used as an energy source if needed
- is required to help us absorb many essential vitamins consumed (hopefully) from our diets
- is imperative to the function of our brain
- is the building blocks for many hormones.
….following a very low fat diet could impair one of these crucial functions!
Fats not being equal is down to their chemical structure and a chemical process called oxidation – the more unstable the fat is chemically, the more likely it is to oxidise and create things called ‘free radicals’. These can be incredibly damaging to the body and have been linked to inflammatory conditions and some serious illnesses like coronary heart disease and cancer.
So, what fats should and shouldn’t you eat?
1) Avoid trans-fats/hydrogentated fats
- essentially these are fats which have hydrogen added to them to typically make vegetable oils more solid (think margarine, spreadable butters), these fats are highly prone to oxidisation (by exposure to heat and light) and should be avoided like the plague
- often used in restaurants for frying due to their cheap cost
- found in biscuits, cakes, crisps, shop-bought fried food and margarine and many other processed foods
- excess consumption of trans-fats have been associated with lower levels of good cholesterol and higher levels of the bad stuff, not to mention an increased risk of heart disease, inflammation and diabetes
2) Saturated Fat is actually the most stable of our fats – but should be eaten in small quantities
- these are not easily oxidised but this does not mean you should eat saturated fat freely!
- they have however, been given a lot worse press over the years than has been warranted, as they play their role in our immunity when eaten in moderation
- if you are frying foods at home, use a small amount of saturated fat (DO NOT BURN IT!)
- sources: grass-fed butter, ghee or coconut oil, all of which are suitable for frying
3) Monounsaturated fats (MUFA) have health benefits
- these are generally liquid at room temperature and solidify in the fridge e.g. olive oil
- they have anti-inflammatory properties
- they can increase insulin sensitivity (by balancing blood sugars)
- they can increase good cholesterol and reduce bad cholesterol
- sources: olives, olive oil, avocados, cashews, almonds, eggs
- olive oil should only be used in cooking at simmering temperatures, DO NOT fry at high heats with olive oil because it can create free radicals
- oils are best used drizzled on salads
4) Polyunsaturated fats (PUFA) have even better health benefits
- these are your omega-3 and omega-6 fats and are called essential fatty acids (EFAs) as you need to get them from your diet as your body cannot make them itself
- your ratio of omega-3 to omega-6 should be close to 1:1; many Western diets however can be as high as 1:20 – this ratio can make omega-6 quite inflammatory to the body so we need a balance
- omega-6 is relatively easy to obtain from your diet so we focus on including omega-3 to obtain this balance
- sources (of omega-3): oily fish (SMASH – salmon, mackerel, anchovies, sardines, herring), flaxseed, chia seeds, walnuts
♥ reduce triglycerides
♥ lower blood pressure
♥ can fight anxiety and depression
♥ fight inflammation
♥ help with brain function and age-related mental decline
General rules I try to live by:
⇒ Keep shop bought oils (olive oil, rapeseed oil, flaxseed oil, avocado, canola etc) in the fridge for better preservation – siphoning off enough oil to be used that week into a dark glass container and keeping in a cupboard – not on the window ledge or work surface!
⇒ Consume 2-3 portions of omega-3 fats per week
⇒ Eat 2-3 servings of monounsaturated fats per day
⇒ Saturated fat should be included in the diet but should be limited to the equivalent of a small knob or two of butter/ghee/coconut oil a day
⇒ Avoid trans-fats wherever possible