what is the predominate form of fat in fish, walnuts, and flaxseed?
They are mostly found in plant foods, such as nuts and oil. They include unsaturated fats -- monounsaturated and polyunsaturated -- and omega-3 and omega-6 fatty acids. Omega-3 fatty acids, which are found in fish, walnuts, and flaxseed oil, are thought to reduce the risk of heart disease. For this reason, three servings of fish a week are recommended. Types of Healthy Fats. 1  Monounsaturated fat is in olive and canola oil, avocados, nuts, and all-natural peanut butter.