Dietary fats have an undeserved reputation for being bad for health and weight, and so people often try to avoid them. However, some fats provide structure, energy, essential fatty acids, fat-soluble vitamins and steroid hormones, all of which are vital for your health. These elements ensure strong cells, healthy skin, good eyesight, maximum brain function, sustained energy, reduced inflammation, optimum nerve functioning, insulation and hormone control. With all these health benefits, it’s easy to see why it’s important not to avoid fats, but instead to eat the correct quantities, of the right types, each day.
Interestingly, the amount of fat you should eat a day depends on your carbohydrate consumption. This is because both macronutrients provide energy, therefore, the less carbs you eat, the more fat you require, and vice versa. Experts don’t agree on the exact balance, but the consensus is the less carbs you eat (within reason) the better your health. Therefore, my recommended ratio for optimum health and weight control is to maintain your protein intake at around 20% and then balance your diet with 60% fat and 20% carbs. As an example, assuming a healthy female wishing to maintain a healthy weight eats around 1800kcal per day, with the recommended ratio of 20:60:20, this would equate to 90g of protein, 120g of fat and 90g of carbohydrates per day. Although these personal daily macronutrient intakes will vary depending on gender, weight, health objectives and activity level, the basic macronutrient ratio remains the same.
For easy calculation purposes, let’s assume that a portion of fat is equal to 18g. This would mean that our theoretical female, eating 1800kcals a day, should eat around 6-7 portions of fat a day, while a man, eating 2200kcals a day, should be aiming for around 8. The list below shows how much of a particular food is required to obtain a portion (or sub-portion) of fat.
1 fat portion (roughly 18g): 18g MCT, coconut, olive & avocado oil, 18g ghee, 22g butter, 25-35g nuts, 32g almond butter, 40g pumpkin & sunflower seeds, 50g coconut, 50g cheddar cheese.
¾ fat portion (roughly 14g): 15g mayonnaise, 25g chocolate (85%), 40g kale chips, 50g mozzarella, brie & halloumi, 75g coleslaw, 80g avocado, 110g oily fish.
½ fat portion (roughly 9g): 15ml cream, 25g chocolate (70%), 40g chia seeds, 60g hummus, 60g falafels, 60g scones, 100g coconut yogurt, 125g sardines in tomato sauce, 170g cottage cheese.
¼ fat portion (roughly 5g): 40g olives, 1 egg, 80g lamb, 80g pork, 100g beef, 100g yogurt, 200g tofu.
Now that you know how much fat you need to eat to be healthy, the next consideration is the different types of fats you’re consuming. Whilst there are many fat variations, most have the same basic chemical structure. A glycerol backbone, with 3 fatty acid chains attached (collectively known as a triglyceride). The properties of each fat molecule, and how they affect the body, depends on the structure and length of those 3 fatty acid chains:
Saturated fats have rigid fatty acids chains, making them solid at room temperature. These fats also have a higher melting point, which makes them a good choice for cooking at a higher heat, but their rigidity can pose a cardiovascular health risk, especially when eaten alongside a high carb diet. So, the recommendation is to eat healthy saturated fats, such as; MCT oil; coconut oil; and grass-fed butter, in moderation (and preferably in the absence of carbs) and avoid unhealthy saturated fats, such as; commercially produced butter; and corn-fed beef, wherever possible.
Monounsaturated fats, also known as Omega-9, are found in foods such as avocados, nuts and olives. These fats contain one less hydrogen atom than saturated fats, making them generally less rigid and liquid at room temperature, but they also have a lower melting point, which makes them less stable in heat. When monounsaturated fats are treated with care (i.e. eaten raw, used for low heat cooking, never being allowed to reach their smoke point and preferably eaten in the absence of carbs) they have many health benefits, including overall weight loss, reduced cholesterol and increased insulin control. However, when they are overly heated, they denature and become bad for your health.
Polyunsaturated fats have more than one unsaturated carbon bond in their fatty acid chains. Like monounsaturated fats, this makes them liquid at room temperature and generally good for cardiovascular health. However, when they are heated, they form even more free radicals, which are extremely detrimental to your health, therefore, foods high in polyunsaturated fats should be eaten raw (other than oily fish). There are different types of polyunsaturated fats, but the most relevant are Omega-3 and Omega-6:
Omega-3 polyunsaturated oils, found mostly in oily fish, are considered the healthiest fats of all. They have been shown to protect against heart disease, inflammation, certain types of cancer, diabetes, Alzheimer’s, and macular degeneration. These fatty acids also have a significant role in regulating blood sugar and insulin levels, helping to burn fat, keeping hunger at bay, and reducing the risk or the ailments commonly associated with being overweight. Until quite recently, fish have been a usual part of our diet, however, due to contamination, the government now recommends that fish should be consumed no more than twice a week, and so fish oil supplements are highly recommended. Without supplementation, Omega-3 deficiency is very common and signs include; diarrhoea; dry skin and hair; hair loss; immune impairment; infertility; poor wound healing; premenstrual syndrome; acne; eczema; gallstones; liver degeneration.
Omega-6 polyunsaturated oils, found in nuts, seeds and vegetable oil, are essential to health, however, the problem is that our diets usually contain far too many of them. Experts suggest that the optimum ratio should be 1-4 Omega-6 (RDA: 4.4g - 6.7g) to 1 Omega-3 (RDA: 1.1g - 2.2g). However, the typical western diets contain 14-20 Omega-6 oils to 1 Omega-3 and this is extremely detrimental to health. Therefore, the general recommendation is to reduce your consumption of Omega-6 fats, while increasing your Omega-3 consumption.
Processed fats are the unhealthiest fats of all. Unsaturated fats, such as sunflower oil, can be made solid by artificially adding hydrogen molecules, in a process called hydrogenation. Hydrogenated oils have a high melting point and remain solid at room temperature. These fats are used for texture, taste and to preserve many processed foods. They also improve the firmness and spreadability of margarines, the flakiness of pie crust, the creaminess of puddings and the crispiness of French fries. The problem with these fats is that the process of hydrogenation creates very unhealthy trans fats. Trans fats are extremely detrimental to health as they are hard foreign substances that can't be properly utilised by your body. They accumulate and clog up your arteries, like candle wax, and create weak cell walls. Research shows that these synthetic fats can increase the risk of cardiovascular disease, cancers, multiple sclerosis, obesity and weight problems in new-borns. Trans fats also occur in small amounts in nature but are much more widely seen in industrially produced margarines, snack foods, packaged baked goods and fast foods.
As you can see the area of fats is fairly complex, however, the general aim is to achieve your daily portions by eating raw monounsaturated and Omega-3 polyunsaturated oils, moderating ‘healthy’ unsaturated fats and avoiding ‘unhealthy’ saturated fats and Omega-6 polyunsaturated oils. In addition, the focus must also be on treating fats well. To achieve all of these recommendations consider the following points:
Eat 2 portions of fish a week (1 oily & 1 white)
Take 2-3 high EPA/DHA fish oil caps a day.
Use coconut oil, avocado oil, grass-fed butter or ghee for cooking and discard all vegetable & seed oils (peanut oil, rice bran oil, sesame oil, soybean oil, walnut oil, cottonseed oil, corn oil, wheat germ oil, hemp seed oil, sunflower oil, grapeseed oil, safflower oil).
Use olive, avocado, flaxseed or MCT oil, on your salads.
Choose grass-fed red meats and moderate your intake of pork belly and egg yolk.
Choose macadamia, coconut, chia and flax seeds and limit your consumption of high Omega-6 nuts & seeds to <40g per day (soya beans, almonds, pistachios, peanuts, pumpkins seeds, Brazil nuts, pecans, sesame seeds, poppy seeds, pine nuts, sunflower seeds, walnuts).
Watch out for salad dressings and mayonnaise (vegetable oils).
Avoid fish canned in sunflower oil. Choose spring water, brine or olive oil instead.
Avoid margarines and spreads.
Limit processed foods (cheap vegetable oils). If you choose whole foods over processed ones, you will probably reduce your Omega-6 intake by a third.
Avoid deep fried foods. Not only are they coated with a thick layer of omega-6 fats, but the cooking process also introduces carcinogenic compounds.
Heating fats destroys their delicate chemical structure and produces carcinogenic substances called acrylamide, therefore, heat fats with care:
Don’t Cook With Polyunsaturated Oils: EFA rich oils, such as, flax, hemp, sunflower, sesame seed oil should not be used for frying as they smoke at lower temperatures.
Don’t Fry With Fat: Instead ‘steam fry’ by adding water, stock, soya sauce or lemon juice. Alternatively, grill, broil, bake, braise, steam, poach, slow-cook and sautéing (with minimal amounts of oil).
Add Water First: If you choose to fry with fat, take note of the ancient Chinese. Traditionally to keep the temperature down they put water in the wok first, then they add the fat.
Add Veg First: Another tip is to put vegetables in the pan before you add the oil to protect the oil from overheating and oxidation. The food maintains more flavours and nutrients.
Don’t Heat Spreadable Butters: These contain higher levels of polyunsaturated fats.
Don’t Over Heat Oils: Anything fried or cooked with high heat, such as fast foods, will produce acrylamide. This has been shown to cause cancer and neurotoxic effects in animal studies and damage to the nervous system in humans.
Never Let Oils Smoke: Heating oils beyond their smoke point generates toxic fumes and harmful free radicals. Always discard oil that's reached its smoke point, along with any food cooked in it.
Don’t Eat Fast Food: Oils kept at 215oC for 15 minutes or more produce arteriosclerosis when fed to experimental animals. Remember in commercial fast food restaurants the same batch of oil is often kept at a high temperature constantly for days.
Fats and oils are also damaged by light, oxygen and age. Therefore, buy them in small batches and keep them sealed in the refrigerator. If you suspect an oil has gone rancid, (bad taste and smell) then throw it away; it’s not worth the risk.
In summary, our fat consumption should be carefully balanced with our carb intake, however, in general we should be consuming around 5-8 portions of fat a day. The majority of our fat intake should be monosaturated and omega-3, and all fats should be treated with care, especially when used for cooking.
BSc (Hons) Nutritional Therapy, memBANT, memNT, memCNCH
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