They can be, very carefully measured.

I'm on a high-ratio keto diet, somewhere around 2.5-3:1 fat to protein plus carbohydrate ratio, with the protein plus carbs mostly protein. Not the usual keto prescription going around these days, more like what they give to kids for epilepsy. Going this tight helps me with some bipolar issues, seems to have an antidepressant effect and my original experiment with a really tight 4:1 ratio showed me that it totally obliviated my tendency to binge on things like peanuts and cheese (and maple syrup and honey...) that developed when I dieted down to 154 pounds on a more protein heavy, lower fat low carb diet. It also coincided with an end to hearing voices. That started in my mid 20's, usually worst when I was under stress, but there was always some residual effect--for instance, running heavy machinery, I'd hear people yelling in the next room (this includes when I was outside and there was no next room).

Anyways, peanuts are keto if you won't binge on them. If I'm very keto, I can eat nuts, peanuts, cheese, I just have to fit them into my ratios very carefully. My reward system seems to work better with keto, I can eat an ounce of peanuts as a snack and by happy with that. Out of keto I'd likely eat--my record is 700 grams of peanuts, 1.4 pounds, because that's the biggest package I've bought. There's a similar effect on alcohol--not that I binge on that, I don't have a tendency binge on it either. But I'll want to drink even less than usual when I'm on a high fat ratio.