Why do you need them?
Fat has received a lot of bad publicity in recent years, and because of this fat is often more misunderstood than carbohydrates. The low fat, high carb craze started in the 1980s, and since then most western countries adopting this eating philosophy have been getting fatter and recording increasingly higher oncidences of obesity year after year. This is no coincidence.
Fats add flavour and fullness to food, and since fats have over twice the caloric value of carbohydrates and proteins, they also help fill you up and sustain your appetite. Low fat food manufacturers strip out the fat from foods and then add sugars, sweeteners and fillers in order to make them look and taste good. After removing the fat and adding alternative ingredients, these low fat foods are often higher in calories than they were when they contained fat, but now they are more likely to send your fat-storing insulin hormones into a frenzy.
Fats, or at least good fats, are actually essential in your diet in order for your body to function properly. Good fats are responsible for the well-being and functioning of your brain and nervous system, as well as providing fuel for your body to convert into energy. There is also a growing amount of evidence to show that ‘good fats’ actually reduce the risk of heart attack and stroke, and assist in long-term weight loss and weight maintenance by helping with sugar and insulin metabolism.
Therefore, it is important to understand the difference between each of the four fat groups and how each of these fats can affect your health and your weight.
Fats – the good, the bad and the ugly
Mono-unsaturated fats have been found to be the healthiest types of fats to consume because of their ability to fight against coronary heart disease and cancer. They are full of antioxidants, lowering your total cholesterol and LDL cholesterol (the bad cholesterol), while increasing HDL cholesterol (the good cholesterol). They have also been found to help in weight loss, particularly that of body fat.
Mono-unsaturated fats are found in:
- animal sources: lean meats, game meats.
- natural sources: olive oil and olives, avocado, peanut oil, canola (rapeseed) oil and raw nuts including peanuts, walnuts, almonds and pistachios.
Poly-unsaturated fats also lower total cholesterol and LDL cholesterol. Almost all polyunsaturated fats in the human diet are from essential fatty acids (EFAs). These are made up of omega-3 and omega-6 fatty acids, which must be obtained from the diet as they cannot be produced by the body.
EFAs are essential for good health as they assist in many metabolic processes. They have been found to fight against coronary heart disease, and there is also evidence that omega-3 oils help prevent or treat depression, arthritis, asthma and colitis.
Poly-unsaturated fats are found in:
Saturated fats have been linked to coronary heart disease, increasing total blood cholesterol as well as LDL cholesterol (the bad cholesterol), high blood pressure and arteriosclerosis (blocking of the arteries). However, a few recent studies have shown that some saturated fats can be beneficial for heart health and endocrine cell production (such as those found in butter, coconut oil, palm oil and animal fats from grass-fed cows, free-range chickens and lard). But even in light of these latest findings, you should limit your saturated fat intake to about 10% of your total daily fats.
Saturated fats are found in:
A note about eggs
Eggs have seen their share of good and bad press in the past 20 years or so, and many people are still not sure whether eggs are a healthy or unhealthy choice when it comes to their cholesterol and general health.
Eggs are actually one of nature’s nutritional powerhouses, and although they do contain dietary cholesterol, they contain more polyunsaturated fat (which actually lowers your cholesterol levels) than saturated fat. Research has also shown that it is actually saturated fat that substantially impacts on your blood cholesterol levels and not dietary cholesterol.
A great reason to include eggs in your diet is that they contain vitamins A, D, E, B1, B2, B6 and B12, as well as the minerals iron, zinc, calcium, iodine and selenium.
Trans-fatty acids (trans fats)
Trans fats are the worst types of fats to consume. They increase your risk of heart disease and are bad for your blood vessels, nervous system and waistline. The ‘very-bad-for-your-health’ trans fats were invented when scientists began to ‘hydrogenate’ liquid oils so that they could perform better in food production and have a longer shelf life.
So, in other words, you can thank the scientists in the food industry for increasing the performance and shelf life of fats at the expense of your health! The only exception to this is the natural trans fats found in meat and milk, which act very differently in the body than those of the manmade kind.
Trans fats are found in many packaged foods, including cookies, cakes, cake icings, doughnuts, baked goods, potato chips, snack foods, roasted salted nuts, microwave popcorn, vegetable shortening, hard stick margarine, fried foods and many foods from fast food outlets.
All the reasons why ‘good’ fats are good for you!
It is important to eat sufficient good fats as good fats are used by the body for:
- animal sources: oily fish, seafood and fish oil.
- natural sources: corn, soy, canola, safflower, flaxseed (linseed), hemp and sunflower oils, as well as pumpkin seeds, sunflower seeds, leafy vegetables, walnuts, almonds and macadamia nuts.
- animal sources: beef, veal, lamb, pork, lard, poultry fat and full-fat dairy products
- natural sources: coconut, coconut oil, palm oil, palm kernel oil (often called tropical oils) and cocoa butter.
- normal growth and development
- conversion into energy; fat is the most concentrated source of energy
- protecting vital organs
- transporting fat-soluble vitamins; vitamins A, D, E, K and carotenoids
- maintaining cell membranes
- bodily functions: from keeping you warm, to maintaining healthy skin, to your metabolic processes
- supplying necessary chemical substrates for hormone production
- building new cells
- normal brain development and nerve function.
How much fat do you need?
When thinking about how much fat you need in your diet it is important to first remember what is outlined in this chapter, as it is not just the quantity but the quality of fats you eat that have a major impact on your health and waistline.
When calculating the amount of good fat to include in your diet, most experts agree that between 26 and 30% of your total dietary calories should come from good fats. If you break this down further, you should consume half of your good fats in the form of EFAs (around 13–15%) as these can also help to significantly speed up your metabolism.