Poly-unsaturated fats include two classes of fatty acids:
Omega-3 fatty acids are very healthy because they enhance the immune system and protect your cells and tissues against degenerative changes. We need omega-3 in our diet throughout the whole life for normal growth and development. In particular, Omega-3 affects the nervous system, brain development, IQ, and cognitive function. Great sources of Omega-3 fatty acids are pumpkin seeds, walnuts, flaxseed, fish and fish oil.
Omega-6 fatty acids are necessary for normal growth and development but still could be unhealthy in excessive quantities. It is also often over-consumed in the typical American diet, so you should keep a balance of your consumption. Usually found in sunflower, corn, sesame, and soy oils.
Mediterranean diet has a healthy balance of Omega-3 and Omega-6 fats which protects you from developing internal inflammation like obesity, cancer, Parkinson’s, heart disease.
Also, you should know that many fat-free foods are high in sugar, so consuming them doesn’t guarantee you are eating healthy. Avoiding fat could make provoke your overeating because fats help you feel full longer. The key is a proper balance between good fats and unhealthy fats. Also, you can limit saturated fats by trimming any fat you see around the meat before cooking.