Your body needs to consume fats to function and should be consumed with every meal, ideally equal portions of each type. They are monounsaturated, polyunsaturated and saturated. What I want to focus on is Omega-3 and Omega-6 fatty acids which make up polyunsaturated fats. In your body, Omega-6 fatty acids are inflammatory which has a negative effect on your body’s systems. Consistently high levels can be a cause for chronic disease and inflammation of the joints. Omega-3 fatty acids, on the other hand, neutralize the effects of Omega-6 damage and work best when consumed at a ratio of 1:1. Realistically, we should strive for a ratio of 4:1. Unfortunately, the current North American diet has a diet closer to 20:1 due to the high levels of corn by-products used in their popular processed foods. Nuts are considered a popular snack option and a great source of monounsaturated fatty acids and Omega-3, but they’re even higher in Omega-6s. Your true defender of Omega-6 overload is flax oil or milled flax seeds, or fresh fish or fish oils that are high in Omega-3 such as salmon.
For a great chart comparing ratios of Omega-3 to Omega-6, check out this link: http://fanaticcook.blogspot.ca/2009/04/omega-6-and-omega-3-in-foods.html
You Can't Out-Train A Bad Diet 