Are you confused about fats? Well, I’m not surprised. For decades, health experts have told us that a low-fat diet is the key to losing weight and managing our health problems. But despite our supermarkets being filled with endless fat-free and low-fat options, our waistlines still seem to be getting bigger, and heart disease, diabetes, and cancer are still on the rise. There seems to be a big, fat minefield of misinformation out there, and it can be hard to separate fact from fiction.
Does dietary fat make you fat?
It’s not just dietary fat that makes you fat. Eating too many calories—regardless of whether they come from fats, carbohydrates, or protein—and not exercising makes you fat. But dietary fat does play a significant role in making you fatter. It’s a rich source of energy, and it’s easy to overeat because it’s in so many processed foods and fast foods. So you do need to be careful of how much you consume.
And a “fat-free” or “low-fat” label doesn’t mean you can eat all you want without consequences to your waistline. Many fat-free and low-fat foods are high in calories and contain high amounts of sugar and refined carbohydrates, which your body can easily turn into fat.
Why you need fats
Fats aren’t just empty calories with no nutritional value. Fats form parts of your vital body structures, help form your cell membranes, and produce hormonelike substances that help regulate your body functions like blood pressure, blood clotting, temperature, immune responses, and inflammatory responses. In addition, fat helps you absorb the fat-soluble vitamins (vitamins A, D, E, and K), and it plays a central role in promoting proper eyesight and brain function.
You need essential fatty acids (EFAs) in your diet as your body can’t make them. Alpha-linolenic acid (ALA), a short-chain omega-3 fatty acid, is found in flaxseed (linseed), hemp seed, chia seed, pumpkin seed, canola, soybean, walnut, and dark-green leaves. Linoleic acid (LA), an omega-6 polyunsaturated fatty acid, is found in safflower, sunflower, hemp seed, soybean, walnut, pumpkin seed, sesame seed, and flaxseed (linseed).
Good fats and bad fats
We’ve all been led to believe that saturated fats are the bad guys and unsaturated fats are the good guys, and that saturated fats from animal products and tropical plant oils are bad and unsaturated fats and plant oils are good. But it’s really not that simple.
There are different types of saturated fats. The shorter the saturated fatty acid, the more easily you can digest it. Short-chain saturated fatty acids are especially abundant in tropical oils like coconut oil, palm oil, and palm kernel oil.
There are also different types of polyunsaturated fats: LA; gamma-linoleic acid (GLA), found in borage, evening primrose oil, and several other seeds; and arachidonic acid (AA), found in meats and other animal products. AAs are healthy in moderate doses, and your body converts LA from plant oils to AA as needed. However, a diet rich in animal products can cause an oversupply of AA, which leads to chronic inflammation in the body.
Studies show that eating foods rich in monounsaturated fatty acids (MUFAs) improves blood cholesterol levels and may benefit insulin levels. MUFAs are found in olives, almonds, avocados, peanuts, pecans, cashews, macadamias, and tropical oils.
These days, we’re also hearing a lot about the dangers of trans fats—they can increase your risk of chronic diseases. Most trans fats are created during food processing through the partial hydrogenation of unsaturated fats. This process creates fats that are easier to cook with and extend the shelf life of processed foods.
Omega-3 fats in plants
Plants only contain the omega-3 fat ALA, which is a short-chain EFA that can be converted to the long-chain omega-3 fatty acids EPA and DHA. However, optimal conditions for conversion are not well-known, and high intakes of the omega-6 fatty acid LA, which is common in a plant-based diet, suppress the conversion of ALA to DHA and EPA. Experts suggest that for optimal production of EPA and DHA, your diet should contain no more than a 4:1 ratio of LA to ALA. EPA is also found in sea vegetables and algae. DHA is also found in algae.
Resources and further reading:
- Fats That Heal, Fats That Kill: The Complete Guide to Fats, Oils, Cholesterol and Human Health by Udo Erasmus [Kindle Edition]
- Fats That Heal, Fats That Kill: The Complete Guide to Fats, Oils, Cholesterol and Human Health by Udo Erasmus [Paperback]
- Fatty Acids: Straight-Chain Saturated by Dr. William Walker Christie
Fiona Halar is a wholefood nutritionist and long-term vegan whose aim is to inspire people with engaging ideas, perceptive insights, and passionate action, to create vibrant health.
Attribution-NonCommercial-NoDerivs 3.0 Australia Licence