I only eat animal fats, as I am keen to have their nutrients. I find beef fat especially nourishing and satiating. Pastured butter is also useful, and some cream. Wild salmon, cod liver oil, and egg yolks "sit" ever so well and seem to provide things vital, as well as occasional liver. If I leave out any of these, I can tell something is missing. I eat what seems to be the right thing for each meal, rather than having an arbitrary, pre-determined menu plan.
To put the fat in context, in case the information is of use:
I eat ca. 20-30 total carbs (not net) per day, which I watch closely. Protein range is 50 - 80 grams per day (of protein grams, not meat weight). The rest of the calories are fat. I don't count the grams of fat. By keeping the carbs at that level, and not going too low or too high with the protein, the amount of fat needed for satiety is easy to gauge. The carbs are divided for each meal, fewer at breakfast. (Dr. Richard Bernstein explains the chemistry of this plan of carbs in his book, "The Diabetes Solution", which I highly recommend, even if one is not diabetic. I do not have diabetes, but found his recommendations immensely helpful, although I eat fewer carbs than his recommended 30.)
On some days, the fat might be 65% of the food, and on other days, much higher.
I am over 55 and slender.
Foods I eat:
Beef, beef fat, liver, chicken liver, fish, egg yolks, pastured butter, cream (mostly as yoghurt), low starch vegetables, herbs. Occasional lemons, olives, and in the summers: cucumbers and a few berries.
I never eat foods not in my plan.
Foods I do not eat:
Grains, sweets/sugars of any kind, legumes, nuts/seeds or their oils, nightshades, sweet fruits, chocolate/cocoa, coffee, alcohol, artificial anything, prepared/packaged foods.
N. B.: For those reading this who are new to evolutionary nutrition:
I have found it immeasurably helpful to follow what Dr. Kurt Harris says, that a healthy metabolic milieu is maintained by the unhealthy things we leave out.
He states this again in his most recent blog entry, in a comment to Phil W., after the blog post:
http://www.paleonu.com/panu-weblog/2011/1/5/guest-post-professor-gumby-essay-001.html
This way of eating is a lifetime choice for me.
ETA: Steve asked a couple of questions in the comments which might be important. I don't drink coffee because I've never been a coffee drinker. Have tried it some over the years and it makes me feel "awful", as though I've been poisoned. (I drink tea in the morning, no flavorings, just a bit of cream, butter, and/or beef fat in it. The Tibetans are inspiring!)
I don't eat chocolate/cocoa because I am allergic. Perhaps it is the alkaloids. It is not important to me, so I haven't bothered to find out. I don't eat egg whites due to allergies. I don't miss them. Egg yolks are grand!
I don't eat nuts due to the phytic acid. Explanation is in the comments. If I can answer something else, I will try. :)
I hope this is of help. Best wishes to all with your food plans.