The low-fat dieting craze has lost some of its appeal lately. However, many of us may still believe an ultra-low-fat diet is the most effective way to lose weight. We may not realize this could be contributing to a very unhealthy lifestyle. Are you eating enough good fats? Or too many bad fats? And what's the difference, anyway?
The Dangers of Eating a Low-Fat Diet
It’s a common story: A new mother embarks on a low-fat diet to shed the last few pounds from weight gain during pregnancy. She completely removes all fats from her diet – after all, are not all fats the same? Her new diet consists of reduced-fat products ranging from milk and mayonnaise to salad dressings and cookies. The list is endless. Calories don’t matter so long as less than 15% to 20% of them are derived from fat. She avoids all types of oil, like butter or extra virgin olive oil, for sautéing. Water or broth work just as well. Nuts, seeds, avocados, and even salmon seem too “fattening”. Only low-fat cakes and muffins are permitted in the kitchen.
Two to three years later degenerating health symptoms begin to appear randomly: depression, forgetfulness, scaly skin, and dry hair that’s falling out. Sugar and carbohydrate cravings become unbearable and are satisfied with binge eating. Eventually serious signs of inflammation begin to appear like arthritis, irritable bowel syndrome, and psoriasis. Then one day it dawns on her that she has been doing it all wrong: this low-fat diet is actually detrimental to her health!
Dietary fats are not only part of a healthy diet, they are vital to our health. Fats are not all the same! The type of fat you consume is most important, not necessarily the quantity. Oils can be saturated or unsaturated, and unsaturated fats can be monounsaturated or polyunsaturated. Here is a description of each.
Polyunsaturated oils, such as flax seed, safflower, sunflower, corn, soy and walnut, do not necessarily prevent heart disease. However, they do lower bad cholesterol (LDL) and increase good cholesterol (HDL). These fats are unstable and should not be subjected to light, heat or air since they oxidize rapidly and form harmful free radicals. Use them to make salad dressings or dips.
The essential fatty acids (EFAs) are unique polyunsaturated fats with numerous beneficial qualities. Linoleic (Omega 6) and alpha-linolenic acids (Omega 3) are the building blocks of fats and are as essential to our health as vitamins and minerals. They are perhaps best known for their heart protective and anti-inflammatory benefits. These oils are converted in the body to prostaglandins, a hormone-like substance involved in the inflammatory process. EFAs also improve blood flow by preventing blood cells from sticking together and causing clots. They are critical for a healthy immune system. They replace unhealthy fats in the body and are metabolized to create energy. These fatty acids also assist in forming cell membranes, regulating gastric acids and pancreatic functions, and helping reduce the risk of degenerative diseases.
If there is an EFA deficiency in the body, symptoms such as a foggy mind, low energy, dry skin and joint problems will eventually appear. It is essential to consume these fats because the human body does not manufacture them. Sources of EFAs include natural whole foods like nuts and seeds, fish, olives and avocados, or they can be purchased as dietary supplements. The average diet contains ratios of 20:1 omega-6 to omega-3. The ideal suggested ratio of omega-6 to omega-3 intake is 5:1.
Monounsaturated fats are much more stable than polyunsaturated fats. They are more resistant to deterioration. Since these oils are more stable, they can be heated. Note that frying these oils at very high temperature does change their molecular structure. These fats can be heated but should not be used for deep frying at very high temperature. Monounsaturated fats include extra-virgin olive, canola, hazelnut, almond, pistachio, sesame, macadamia and peanut oils. Cold-pressed, unrefined oils such as monounsaturated fats also contain lignans, which promote health and assist in cancer prevention.
It is important to replace bad fats and oils in our diet with good ones, and to understand that industrial processing and frying may change good fats into bad ones. In the past foods were produced locally and naturally, and had a short shelf life. Today foods are highly processed to extend their shelf life to accommodate the lengthy traveling time before they reach the grocery store. The health issues we experience in the Western world are not a coincidence. Cancer and obesity rates have dramatically risen, and our generation is plagued with degenerative diseases. For the most part North Americans die from food related diseases.
Many dietitians and scientists tell us to reduce overall fat intake without distinguishing between the good and the bad fats. Many people believe saturated fats are bad for us. Saturated fats are hard at room temperature and include butter, raw coconut oil, palm oil, lard and animal oils. However, saturated fats do not cause heart disease, are very stable, and are much healthier than processed margarine! For example, butter is a good fat. It does not put any stress on the liver because it is easily digested. The mono and poly-unsaturated fats are supposed to be good for us, however, this can be misleading too. Neither saturated, nor unsaturated, fats are bad for us in their natural states. These fats are extremely healthy for us as long as they are unrefined, non-hydrogenated, and not exposed to high temperatures.
Trans fats are made from liquid vegetable oils (chemically unstable) that are hydrogenated (a heat treatment that adds hydrogen to the oil to fill in missing hydrogen molecules). This makes the vegetable oil more stable and solid. Bioactive substances that cause rancidity are also removed. Trans fats provide an inexpensive way to enhance the taste and increase shelf life of processed foods. They are stable enough for deep-frying and can replace butter and lard in baking. Margarine and shortening is vegetable oil that has been hydrogenated.
However, the heat process of hydrogenation converts the good fatty acids into harmful acids. This process is hazardous to our health and compromises our immune system by creating leaky cellular membranes. Consuming trans fats increases LDL (bad) cholesterol and decreases HDL (good) cholesterol. Our body cannot melt trans-fatty acids. Consequently, they cannot be metabolized. Trans-fatty acids are actually toxins inside the body. Read labels to identify food products that contain hydrogenated and partially hydrogenated fats.
Good fats don’t make you fat! In fact, they assist in healing your body and promote fat loss. Keep your fat intake to about 25% of your daily calories (that means if you eat 2,000 calories a day, 500 calories, or 55.5 grams, should come from fat). Replace all unhealthy dietary fats with untreated natural fats and oils found in nuts and seeds, fish, and cold-pressed extra-virgin olive, canola, almond, sesame, macadamia, hazelnut and pistachio oils. Oh, and don’t be afraid to use butter!
And, you may ask, what about low-fat foods? You should also know that, in many low fat foods, fat is often replaced with sugar, which causes havoc inside our body!
Image: Tee Poole