THANK YOU Dr Bass, excellent timing.
This paper is being discussed in various nutrition fora at the moment.
It's a classic. You read the abstract and realise a high fat diet is mangling your brain. Oh no! Quick, don't bother reading the paper, get rid of the fat. Oh, you can't read the paper unless you have an account. Well, by chance, I have the full paper.
Ok, it's a "High Fat" diet alright. Up at, you guessed, 45% of calories from fat, mostly as lard. In fact it is the D12451 rodent diet. A quick Google of D12451 gives you this page. You don't get this info in the full text of the paper, you have to want to know!
You can see that the carbohydrate composition is a smidge of cornstarch (73g), a mass of maltodextrin (100g) and a huge mass of sucrose (173g) in an 858g block of food. This diet is designed to produce sugar addiction, obesity and diabetes. Adding some healthy lard will not save the poor mice from Bass et al's "High Fat" sucrose diet.
This paper does not involve a high fat diet. It's junk.