The discovery that monounsaturated fat could be healthful came from the Seven Countries Study during the 1960s. It revealed that people in Greece and other parts of the Mediterranean region enjoyed a low rate of heart disease despite a high-fat diet. The main fat in their diet, though, was not the saturated animal fat common in countries with higher rates of heart disease. It was olive oil, which contains mainly monounsaturated fat. This finding produced a surge of interest in olive oil and the "Mediterranean diet," a style of eating regarded as a healthful choice today.
The reality is, not all fats are created equal. Some are downright bad (like trans fats in margarines), some are misunderstood (like the saturated fat, lauric acid), and some fats are health heroes (like omega-3s). And, don’t get us wrong, eating foods that are packed with the wrong kinds of fat will make you fat, but with all the omegas, and monos, and polys out there, it can be kind of confusing which are which. To make things easier for you, we here at Eat This, Not That! found the best foods with good fats that you can add to your diet. But before you go off on a high-fat binge, remember that—like all food—even these healthy fats should be consumed in moderation.
Fat droplets start to pass through the duodenum where bile acids are added (bile acids are from cholesterol in the liver and stored in the gall bladder). Bile acids are really cool because they act like soap breaking and emulsifying the fat droplets and making them into even smaller droplets. I like to use the visual of washing a pan with grease on it with soap, at first the grease barely comes off, but with a little muscle and scrubbing with soap the detergent breaks up the fat and grease into very small particles until it’s gone.
Fat tends to be considered “bad” because it is associated with weight gain and high cholesterol. However, certain types of fat give protective benefits to the heart if appropriate portions are consumed. The key is to understand how to choose the right amount of each type of fat, so we should look closely at the ideas of total fat and each type of fat.
Saturated fat. This is a type of fat that comes mainly from animal sources of food, such as red meat, poultry and full-fat dairy products. Saturated fat raises total blood cholesterol levels and low-density lipoprotein (LDL) cholesterol levels, which can increase your risk of cardiovascular disease. Saturated fat may also increase your risk of type 2 diabetes.
Omega-3 fatty acids promote health in several ways. They reduce inflammation and lower the risk of chronic diseases including heart disease, cancer, and arthritis. Omega-3 fatty acids can help lower triglycerides and apoproteins (markers of diabetes), and raise HDL (“good” cholesterol) levels (8). Omega-3 fats are also essential for brain and eye health (9).
Remember pancreatic lipase from earlier in the duodenum? Well, lipoprotein lipase breaks down triglycerides for absorption which goes into the fat tissue for storage, or it’ll be absorbed in muscle tissue for energy. Where do the chylomicrons go? Basically, they shrink so much that they just become tiny little particles that used to be. They’re absorbed into the liver and then the liver metabolizes them. The liver is key for fat metabolism! Liver health = fat digestion efficiency = healthy fat burning potential.
Healthy fats have numerous benefits for your body when included as part of a healthy balanced diet. A diet which includes moderate to high amounts of monounsaturated fats can be useful in weight loss, as long as you don’t eat more calories than you are burning. A large study which combined the results of twenty four other studies found that participants who followed a high-monounsaturated fat diet had more effective weight loss than those who followed high-carbohydrate diets (10).
There are two basic kinds of fat, saturated and unsaturated. Unsaturated fats are considered “healthy fats” include both polyunsaturated and monounsaturated fats. These types of fats are typically found in vegetable oils that are liquid at room temperature, fatty fish, (salmon, trout, catfish, mackerel), and nuts and seeds. Polyunsaturated fats include Omega-3’s that are the building blocks of cell membranes I mentioned earlier. Omega-3’s also give your body energy and help support your hormones and immune system (3).
So you might assume that fat is to blame for the obesity epidemic now plaguing our nation. Actually, fat is only part of the problem. Obesity is much more complicated than just overeating a single nutrient. Eating more calories -- from fats, carbohydrates, protein, and alcohol -- than you burn off leads to weight gain. Simply put, people who get little physical activity and eat a diet high in calories are going to gain weight. Genetics, age, sex, and lifestyle also weigh into the weight-gain formula.
The type of fat with no redeeming nutritional value is trans fat, which is created when food manufacturers artificially convert unsaturated fatty acids into solid, saturated fats. Trans fats have the worst effect on your cholesterol levels, because they actually lower the good HDL cholesterol and increase the harmful LDL cholesterol. They're also highly inflammatory, which may contribute to chronic diseases, and they contribute to insulin resistance, which drives diabetes development.
However, many experts disagree with the report’s conclusions on a few fronts. First, the link is based on the reasoning that saturated fat raises total cholesterol levels, but many studies suggest the link between higher cholesterol numbers and heart disease risk has been overstated. And while LDL is often referred to as “bad” cholesterol, there are different types of LDL, and the total number may be less important than the composition of the actual particles. Small, dense particles are inflammatory and associated with heart disease risk, while larger particles are not.
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First, focus on reducing foods high in saturated fat, trans fat and cholesterol. Then emphasize food choices that include plenty of monounsaturated fats (MUFAs) and polyunsaturated fats (PUFAs). But a word of caution — don't go overboard even on healthy fats. All fats, including the healthy ones, are high in calories. So consume MUFA-rich and PUFA-rich foods instead of other fatty foods, not in addition to them.
Healthy fats are unsaturated fats that are found in fatty fish like salmon, avocados, nuts and seeds, plant oils that are liquid at room temperature like olive oil, and coconut oil. Coconut oil is contested as a healthy fat because it is a saturated fat, but because the majority of its fat content is medium-chain triglycerides (MCT), I consider them an exception.
Cutting back on saturated fat will likely have no benefit, however, if people replace saturated fat with refined carbohydrates. Eating refined carbohydrates in place of saturated fat does lower “bad” LDL cholesterol, but it also lowers the “good” HDL cholesterol and increases triglycerides. The net effect is as bad for the heart as eating too much saturated fat.
Ideally, you’ll want to consume minimally-processed foods that are full of heart-healthy, polyunsaturated omega-3 fatty acids (ALA, DHA, and EPA), monounsaturated fats (OEA), and the trans fat conjugated linoleic acid (CLA), as well as some medium-chain saturated fats like stearic acid and lauric acid. On the other hand, stick to foods that have low levels of omega-6 fatty acids and other saturated fats (palmitic acid), and zero manmade trans fats (partially hydrogenated oil). According to the Dietary Guidelines, an easy way to do this (besides following this list) is to lessen consumption of the top sources of saturated fats like pizza, burgers, meats, and processed snacks and sweets.
Hi, and Thank you for a very interesting website. I read the newsletters with curiousity and I learn new things. I am a Norwegian woman who started with LCHF diet/ keto three months ago. My motivation was serious healthchallenges with IBS, which became increasingly difficult after an gut infection last summer. My gut is much better! Not “perfect”, but the difference from three months ago is huge. My energy level is also coming back to normal, and even better! I have a question about canola oil. I am confused. I thought it was healthy, and that the balance between omega 3 and 6 was good. Canola oil is a preferred oil, together with olive oil, coconut oil and butter, on dietdoctor.com and other lowcarb-websites and books. So I wonder, why is it in your opinion on the “not to eat” list? Is it something that happens with it during the process of production? Or? Kind Regards, Mona Sommer
The worst type of dietary fat is the kind known as trans fat. It is a byproduct of a process called hydrogenation that is used to turn healthy oils into solids and to prevent them from becoming rancid. Trans fats have no known health benefits and that there is no safe level of consumption. Therefore, they have been officially banned in the United States.
Along with nuts, seeds get high marks as healthy fats to improve good cholesterol. And flaxseeds are especially popular among nutritionists because of their versatility in a heart-healthy diet. “Sprinkle flaxseeds onto whatever you like,” says Haisley. “My favorite is with Greek yogurt or on my oatmeal. It is a great addition to salads or whisked into your favorite homemade salad dressing. You can even bake with it, too; try using 3 tablespoons of flaxseed in place of 1 tablespoon of oil or margarine in your muffins.” Try these cranberry-nut mini loaves with flaxseeds.