You want fats with a balanced omega 3:6 ratio, which generally means animal fats.  Fish count as animals.  Avoid hydrogenated fats; avoid liquid vegetable oils which generally have a very poor omega 3:6 ratio.

With a prior heart attack, I'd say fatty fish is your best source of fat for the first few years.  You might consider a small vitamin C supplement - or a large one if you eat very much fruit, which is the main source of carbohydrate on paleo.

My advice: oily fish is better than fish oil supplements. There is clear evidence that fish is good for health, but the evidence for supplements is mixed. If you like salmon, eat more of it and cut the supplements. Emphasise red meat over pork and poultry - the fat profile is healthier. Buy grass-fed if you can. Lots of nuts aren't good for you - too much omega-6. Macadamias are OK, other nuts should be limited to a handful a day, less if you can't get grass-fed meat. Coconut oil is healthy, but can cause digestive upset if you're not used to eating it and suddenly eat heaps. Start with a teaspoon or two per day and gradually build up to about 4 tablespoons. Cold-pressed olive or macadamia oil is OK for salad dressings. Avocado is a healthy way to get more fat.

Do not eat soy, canola, corn, sunflower, safflower, rice bran, grape seed, flax seed, peanut or "vegetable" oils. Do not eat anything that has been heat/hexane extracted (ie any vege oil that doesn't say it's cold-pressed). Do not eat any fat that is hydrogenated, partially hydrogenated, interesterified or otherwise processed. Do not eat any commercial baked goods, snack foods or fast food.

Try to buy 100% grass fed beef and bison, pork if you can find it, pastured chicken, and game (venison, elk, wild boar, etc.). Note that just because it says "grass fed" does not mean it is not "grain finished". It must either say "100% grass fed" or "grass fed and finished" on the packaging.

Ideally, yes, though it may be expensive.

100% grass fed beef and bison has as much or more Omega 3s ounce per ounce as wild salmon.

I don't believe that's completely correct.  Grass finished beef has as good an omega 3 to omega 6 ratio, but less of each.

I don't believe that's completely correct.  Grass finished beef has as good an omega 3 to omega 6 ratio, but less of each.

Warren, yeah, sorry, got some of my research stats mixed up. Grass fed/finished beef has pretty close to a 1:1 O6 to O3 ratio, like wild salmon, but yes, less total omega fatty acids.

There is still emerging data on this though, and a lot of confusion because the long-chain fatty acids are in the fat, not so much in the muscle tissue (meat). The problem is that we American's typically eat lean meat, and that is often all we can buy, so the omega benefits of even the best beef are largely lost on us.

I personally buy 100% grass fed beef that is between 30 and 40% fat. It is delicious. I also buy grass fed beef suet, and add it in various ways to my food. I'd like to see an analysis on the O3 content in wild salmon fat versus 100% grass fed beef fat some day. Hopefully I'm eating right in the mean time because while I like wild salmon, I don't like it enough to eat it often, and I certainly can't afford to eat it as often as I probably should.

I don't understand why that's the case. From my time in the US, fat was either being thrown away (even grass-fed fat, which was being routinely stripped and thrown away by those morons at Whole Foods) or sold at a discount (eg: 80/20 minced being cheaper than 90/10).

Most people in the U.S. have really bought into the whole lipophobia thing.  Even the grass finished roasts I order on line have all the fat removed now, sigh.