I'm not an expert, and can't answer directly, but I tried things out and noticed how they affected me. Of course YMMV.
I don't know what fatty cuts of meat are exactly. As I said, I'm no expert. I usually buy 100% grass-fed beef. Grass-fed is leaner. I eat pork and fish, mostly cod or haddock. My DW likes Salmon, I don't care for it.
Fish, beef and pork, typically, once a week each.
I eat European dairy almost every day. Europe uses A2 cows. My DW has a problem with A1 milk, which most of the US is. A1 cows give more milk and the US prizes profits above health.
I find cheese a good source of protein, although it is higher in fat, that doesn't seem to bother me.
I do not eat chicken, and almost no egg yolk, although I do eat egg whites, which I put cheese in to give it some flavor.
Nuts, I eat every day. My breakfast is usually 18 raw almonds and a couple of cups of tea (stevia and heavy whipping cream in dark tea, only stevia in green).
Mid morning I'll have a whey shake, I get this brand
https://www.amazon.com/Raw-Grass-Fe...ps%2C146&sr=8-5
They have an organic version, but I can't afford that. They use Jersey cows (a2 milk) and the cows are grass-fed. I put some stevia and extract in it for flavor.
I usually drink coffee in the afternoon. Caffeine doesn't do anything to me, I drink the tea and coffee because they taste good and are good for me. I can drink 2 cups of coffee and go to sleep. I read about this and think I am a slow caffeine metabolizer.
I eat keto bread, either from Aldi or Netrition.com and never eat the regular stuff. I think even whole wheat is too carby for me. I limit my carbs to fewer than 20 per day to stay in ketosis. A local 'health food' store sells millet and flax flatbreads that are low carb and wheat free.
I eat a lot of nuts, and organic nut butter. Good protein with fiber, keto friendly, and I like them.
I can eat nightshades but sadly they bother my DW.
Keeping my carbs under 20 per day is what I need to stay in ketosis, so sadly, most fruit is out.
I was keto before the arthritis/bursitis diet was recommended to me by a doctor. But I had inherited bursitis from my father that was so bad, I couldn't walk two blocks without sitting, and I couldn't drive without one of those 'blue ice' packs behind my hip. Now I can walk 2 to 4 miles for exercise, and drive all day if i want to.
My main problem was a lot of chicken and eggs. These have the highest Arachidonic Acid amounts, by far. I really love chicken and eggs, but I like being pain free and not wrecking my body.
Everybody is different, but I'd rather give up foods than to live in pain. My diet is limited, but I'm healthy. I get some keto friendly foods via netrition.com that satisfy the urge once in a while. Even then, I have to be careful, as 20 carbs per day is not very much.
I'm going to be 76 this month, on zero prescriptions, a heart doc tested me and says I have a circulation system of a healthy 50 year old person, and I feel healthy. I finally have a BMI of normal. I figure good health is the most important thing. Without that, nothing else matters.
If I had to eat the same thing every day to be this healthy, I would. Fortunately I can have limited variety.
Bob