When it comes to fats and a local diet, it is super easy to avoid the worst fat-trans fat. It's just unnatural. It usually comes pre-packaged, and I don't mean the cardboard box my csa delivers in. The key beyond trans-avoidance is to limit your saturated intake and balance your omega 3s and 6s one to one. The average American diet has the 6s way out of control. A long chain omega-3 supplement (food or pill) is recommended.
My diet does not look like this ideal. My cooking fats (the local ones) are not oils, they are butter and leftover fats from meat. (When I do eat meat, I use the whole meat. It's out of reverence for the animal. Eat bacon, save the grease. Make a roast, skim the fat; ditto for gravy and broths. I save the fats and use them to saute.) Animal fat is saturated any way you spin it. Adding full-fat cream to coffee, scones, and pies is another way I'm just rampantly consuming these 'bad' fats.
Local sources of healthy fats in the diet are here: walnuts, hazelnuts, salmon, tuna, and oysters. But I don't like to consume the precious fish in the sea daily, even weekly. It is too much, more than my allotment in my opinion. Some would recommend a fish oil supplement, but then, that's coming from fish...you might as well just eat the fish whole instead.
I do use oils when cooking if I'm out of left-over fats. I always have some canola oil around. A note about that though, we are switching to organic only canola. Small farmers are being penalized by big gmo companies because the 'roundup-ready' gene is infiltrating their rapeseed crops. The big company just samples a small-timer's field and can prove that they 'stole' the gene. A lot of little farms get shut down or at least have to pay a settlement to the big guys this way. Organic farmers have a leg to stand on because they don't benefit from a 'round-up ready' rapeseed gene. I encourage you to support the organic canola industry as well.
Another fat that gets a lot of use around my house is olive oil; mostly just used for dressing salads. We buy it in bulk and keep a small bottle in the cupboard that is continuously refilled from the giant tin. Buying giant tins of olive oil is better than buying individual glass bottles because at least you are downsizing on the amount of packaging that is used and shipped. I also try to buy a California olive oil instead of one from Europe. It's the more local choice overall; but southern Cali isn't exactly local.
While I do get some omega-3s from the walnuts in my homemade granola, I could stand to add some more. We canned a whole tuna this summer and we consume those jars periodically. In addition, Dan caught two steel head trout, one or two fillets remain in the freezer. I do think that we could stand to have some more of these polyunsaturated fats in our diet though. Perhaps adding some flax seeds in our granola could be local?
After some Internet searching I found a local farm, A2R in Corvalis, that is going organic with flax seeds, oats, and wheat. Unfortunately I just missed their recent 'stock your pantry' sale. I am penciling it in for next year. A good thing I learned from this research is that Nature Bake has just come out with a bread with a lot of this farm's products called Oregon Grains Bread. I'll be sure to check it out!
Eating locally might not be the best answer for your body's health, but for your overall health as a human it can be the right choice for you. I will continue to eat local fats, despite the high amount of saturated fats that I'm consuming. Using some organic canola oil and California olive oil as supplements to my fat intake seem to be reasonable, as well as supplementing some flax seeds into my morning granola.