Just like the other macronutrients, protein and carbs, fat is essential to good health. Fats, like carbs have been demonized, but fat consumption is needed for the body to function properly and for the appearance of glowing skin and strong healthy hair.
There are many benefits to consuming fats. One such benefit is a satiated feeling, i.e. your tummy feels full when you eat fat, which helps curb appetite and can result in weight loss. Other benefits include providing energy, reducing cholesterol, helping your body absorb vitamins by slowing digestion, and brain health.
Now don't go out and eat just any old fat. Not all fats are created equal. There are two categories of fats, saturated and unsaturated. Unsaturated fats are the good fats and are included in such foods as olives, brazil nuts, flax seeds, walnuts, hazelnuts, avocados, and other nuts and seeds.
Avoid the saturated fats, as they raise cholesterol levels, clog arteries, and increase the risk for heart disease. These fats are found in animal products, so if you are vegan they are really easy to avoid.
So fats are essential and you need them, but remember to not over do it. Take a look at the Dietary Reference Intakes Calculator to determine how much fat you should consume daily.