A brief overview on the foods that I'm currently eating, and what I'm definitely avoiding (apart from special occasions/unavoidable situations).
I've started compiling a nutritional table here
Pretty much all meats are acceptable, but the less processed the better. Generally, if I buy cooked meat I try and buy good quality from a butcher or reputable meat counter in a supermarket and make sure there are no additives, but that's not always possible. Because of this, I'll genuinely cook my own meat even if it's to eat cold for lunch at work the next day.
The same approach as meats, attempting to buy good quality fish, preferably not farmed. Oily fish are especially good, specifically: -
Oils (and sources of oils)
This is more complicated, as you need a good balance of essential fatty acids (omega 3 and 6 from sources such as fish) and saturated and monounsatured fats.
A great link for a more in-depth look at fats here
Oils containing monounsatured fats are generally ok for 'light cooking', but they have a low smoke point and so should generally be used cold.
These are all good for cooking with, and the higher the 'smoke point', the better. Generally I use a combination of coconut oil and butter when frying, and just coconut oil when roasting.
Polyunsaturated fats have a low smoke point and can emit harmful free radicals on oxidisation, so should only be used cold.
Nuts and Seeds
This is quite hard, as the amount of fats and the type of fats in nuts vary greatly and confusingly, some nuts are not actualy nuts, but legumes
These are higher in carbohydrates, so need to eat less of these if possible.