The guidance on saturated fat is a little more complicated. Old nutrition research said saturated fat was really bad for your cholesterol levels, but newer information suggests it has a more neutral effect. The topic is very touchy, and the USDA Dietary Guidelines and the American Heart Association still recommend limiting your intake and opting for monounsaturated and polyunsaturated fats instead. Many of the healthy foods below have some saturated fat in them, but it doesn’t make up the majority of the fat content and won’t negate the positive effects of the healthier fats.
Polyunsaturated fats are required for some of the normal body functions listed above, but the body can’t produce them so they must be obtained from foods. Omega 3 fatty acids are a type of polyunsaturated fat and can be found in cold-water high-fat fish like salmon, mackerel, and sardines, and in flaxseeds, chia seeds, walnuts, canola oil (again look for non-GMO or organic), and unhydrogenated soybean oil (also look for non-GMO or organic as most soy products in the US are GMO unless they specifically state non-GMO or organic.) Omega 3’s are also found in some greens, including romaine, spinach, and arugula. Note that the body only partially converts plant-based omega 3’s to DHA and EPA, which are found in cold-water fish
Today’s Basics topic is all about fat! We’ve covered other macronutrients here on the Nutrition Stripped blog such as carbohydrates, protein, and digestion, and now the list is growing! Out of all the macronutrients, people have the most misconceptions about by fat! Today I’m sharing a breakdown of food sources of healthy fats, the function of fat in the human body, how fats are digested, and how our bodies store fat. If I haven’t lost you yet, keep reading on to learn the basics of healthy fat from a dietitian’s point of view. Let’s jump in!
Trans fat. Small amounts of naturally occurring trans fats can be found in meat and dairy products but it’s artificial trans fats that are considered dangerous. This is the worst type of fat since it not only raises bad LDL cholesterol but also lowers good HDL levels. Artificial trans fats can also create inflammation, which is linked to heart disease, stroke, and other chronic conditions and contributes to insulin resistance, which increases your risk of developing Type 2 diabetes.
Nuts like pecans, pistachios, cashews, and almonds also pack a lot of healthy fats. Almonds are the richest in vitamin E, and pistachios have lutein and zeaxanthin, carotenoids important for eye health. All you need to eat is a 1/4 cup serving per day to reap the benefits. Some varieties are fattier than others, like cashews and macademia nuts, so you need to pay closer attention to serving sizes. (Nuts have, on average, 45 grams of fat per cup.) Nutritionists love pistachios because the fact that you have to shell them helps you eat slower and naturally control portion size. The peanut (technically a legume) contains monounsaturated fats but all of its polyunsaturated fats are omega-6s, which evidence suggests may not do us any favors.
Although fat is an essential part of the diet, keep in mind that most high-fat foods are also considered calorie-dense foods. When increasing your intake of healthy fats, it’s important to account for this by making modifications to your diet, such as decreasing your intake of refined carbs or sweets. Without making a few simple swaps to your diet, adding high-fat, high-calorie foods can lead to weight gain.
Research supports the effectiveness of consuming more healthy fats. In a recent study of 60 people with mild abdominal obesity, researchers found that eating a high-monounsaturated-fat diet or a Mediterranean diet, which contains both monounsaturated fats and omega-3 fats, raised HDL cholesterol levels and lowered low-density lipoprotein (LDL) levels. And a number of studies have shown that having a higher HDL level reduces the risk of heart disease and might also reduce the chances of plaque building up in the arteries.
Out of all the fish in the sea, tuna is one of the highest sources of docosahexaenoic acid (DHA), an omega-3 fatty acid. Canned light tuna is one of the best and most affordable fish for weight loss, especially from your belly! One study in the Journal of Lipid Research showed that omega 3 fatty acid supplementation had the profound ability to turn off abdominal fat genes. And while you’ll find two types of fatty acids in cold water fish and fish oils—DHA and eicosapentaenoic acid (EPA)—researchers say DHA can be 40 to 70 percent more effective than EPA at regulating fat genes in the abdomen, preventing belly fat cells from expanding in size.
That said, dietary fat plays a significant role in obesity. Fat is calorie-dense, at 9 calories per gram, while carbs and protein have only 4 calories per gram, and alcohol has 7 calories per gram. It's easy to overeat fats because they lurk in so many foods we love: french fries, processed foods, cakes, cookies, chocolate, ice cream, thick steaks, and cheese.
But wait, bile isn’t the only thing added in here, our pancreas also adds pancreatic digestive juices called lipase to the duodenum which helps break down triglycerides into two fatty acids and a monoglyceride. After this step, though, the fat droplets don’t just disappear. Instead the fatty acids and monoglycerides are absorbed in the microvilli (remember these from Digestion, part I?) and reassembled into triglycerides.
Fat, fat, fat! Would all of our weight loss problems be solved if we just eliminated fat from our diets? Unfortunately, it's not that simple. We actually need fats -- can't live without them, in fact. Fats are an important part of a healthy diet: They provide essential fatty acids, keep our skin soft, deliver fat-soluble vitamins, and are a great source of energizing fuel. But it's easy to get confused about good fats vs. bad fats, how much fat we should eat, how to avoid artery-clogging trans fats, and the role omega-3 fatty acids play in heart health.