If you eat fat your going to get fat right?...wrong!
In fact in some cases it can be quite the opposite, eating fat could make you thinner.
I think it's mainly down to media hype that this misconception of eating fat is bad and makes you fat has come about. Unfortunately it has become such an accepted fact amongst the general public. This should not be confused, fat will not make you fat, in fact you need good quality (aka smart) fats in your diet in order to build muscle and burn body fat. It also plays a number of important roles within the body including energy expenditure, vitamin storage and the production of optimal testosterone levels.
With that said, some fats should be avoided at all costs. Hydrogenated and trans fats found in crisps, cakes, sweets and biscuits etc. should be eliminated from your diet as these are bad for you and will kill your muscle building/fat loss efforts. Fats that are encouraged to be eaten are monounsaturated fats and omega 3's. These are found in foods such as almonds, salmon, avocado and olive oil. It's worth noting fat contains 9kcal per gram, making them an excellent addition to your diet if your aiming to gain some size and get some extra calories in your body. Eating omega 3's with your meals provides beneficial effects that regulate your blood sugar levels - perfect for fat loss!
Remember - don't eliminate fat, just be smart over the types your eating.