Additional sources of fat:
This group includes foods like nuts and seeds, as well as their respective butter forms. Additionally, olives, etc.
These fats are my favourite to use, as they are used in their complete composition, i.e. as a wholefood, without the need for extraction of the oil from them. Part of me likes to think mama nature knew what she was doing in creating these to be eaten as they are, where in addition to high quality fatty acids, these also contain fibres (which help regulate the amount of fats our body actually takes up from these) and high quality protein. I like to make wide use of these fats in my food preparation, in places of extracted oils.
Studies have shown that eating nuts and seeds in their whole form increases long term satiation and reduces hunger, whilst their digestion does not actually lead to full absorption of the fats within them, with respect to the form the nuts are eaten in, the less processed, the more pronounced this effect.