you should try to consume your fats through multiple sources
nuts, Olive oil, almond butter, Avacados, Peanut butter, salmon just to name a few.
nuts are a great source of fat, having a good amount in poly and mono fats, but they favour more monounsaturates, therefore they don't really subsitute for fish oils and flax.
You also need to consume fish oils/flax to bring the omega 3 + 6's up.
You just gota remember that omega 3 and 6 fats are EFA's and ur body cant produce them. So fatty fish and flax would definatley be something worth looking into. Nuts alone will not be optimal.
pss. theyre not only good for weightloss, they are essential for building muscle, as these fats increase testosterone levels/absorb fat soluble vitamins/help your immune system and more.