Out of all the macronutrients, fats are the most nutrient dense so it is natural to think that we should cut them down as much as possible if trying to lose weight, right? If we go back almost 50 years, the U.S. government first told us to eat little fat and minimize saturated fats to reduce the risk of cardiovascular disease, cancer, high blood pressure, and a whole lot of other problems, so we saw a change in the food industry benefiting low-fat foods. They did not predict the change would do nothing to slow the rates of heart disease, obesity, and type 2 diabetes in our country. Ironically, the prevalence of these problems continued to climb!
So…does eating fat makes me fat? Not exactly, especially when you are eating the right kind of fats. With that being said, all fats are NOT the same. Among the fats, there are some that are bad and some that are good. Trans fat, or hydrogenated fats, are created by a chemical process that turns liquid fats (oils) into semisolid or solid fats at room temperatures to prolong the shelf-life of products and reduce the need for refrigeration. This ingredient is commonly used in pre-packaged baked goods, snack items, fast foods, margarine, and shortenings — also referred as "partially hydrogenated oils" on food labels — and are associated with an increased risk for heart disease. This is why it’s helpful to avoid products made with hydrogenated or partially-hydrogenated oils.
Then there are the saturated fats. Some studies have shown diets rich in saturated fats can increase LDL (the “bad”) cholesterol, which can increase the chances of blockages to form in arteries in the heart and elsewhere in the body. However, some recent studies call that health risk association into question; regardless, more research is needed on this subject. Due to the potential for causing heart problems and weight gain, nutrition experts recommend limiting saturated fat to less than 10% of your daily calories intake. Saturated fats are generally found in animal fat sources, are naturally solid at room temperature, and commonly found in foods such as lard, butter, milk fat, fatty cuts of red meat, ice cream and cheese.
Now let’s talk about the good fats or the fats that you want to eat more of than the other kinds, unsaturated fats. Unsaturated fats are further broken down into monounsaturated fats and polyunsaturated fats. The Seven Countries Study during the 1960 revealed that people in the Mediterranean region had a lower rate of heart disease despite a high-fat diet. The main fat in their diet comes from olive oil, which contains mainly monounsaturated fat. Replacing saturated fats with monounsaturated fats can help lower LDL cholesterol without lowering the HDL cholesterol. Some good sources of these healthy fats are olives and olive oils, avocado, as well as nuts and seeds.
Polyunsaturated fats have also been shown to improve the ratio of “good” HDL to “bad” LDL cholesterol in the blood. The well known omega-3 fatty acids, which cannot be produced in the body at adequate amounts, belong to the polyunsaturated fat category. They are essential fats, used in maintaining a whole host of body functions. Some rich sources of polyunsaturated fats and omega-3 fatty acids include fatty fish such as salmon, mackerel, and sardines, flaxseeds, and walnuts.
Our bodies need fats to function normally and healthfully! Roughly 20-30% of our total daily calorie intake should be coming from fat. Next time you are on a shopping trip and are confused about which foods are good or bad fats, bust out the ShopWell app to help you sort through!
Wayne is a Silicon Valley local. He holds a B.S in Clinical Nutrition from U.C. Davis and M.S in Sports Nutrition from Marywood University and is a current dietetic intern at Fresno State. He spends most of his time weightlifting and running which is probably unbalanced by his major weakness for desserts.