the carnivore diet is yeah just people eating solely meat for breakfast lunch and dinner. In its most extreme it's the Jordan Peterson diet of beef water and salt. Most people allow themselves to eat other types of meat though, and some take it to include all animal products including milk and butter. But honestly most people I've seen don't do raw meat, they literally just buy a ribeye from the grocery store for breakfast lunch and dinner. The most extreme do eat raw meat, organ meats and fermented meats though.

They push the seed oil thing as part of their effort to convince everyone that plant products are actually killing us and are the cause of all chronic diseases, cancer, heart disease, etc, and we'd all live to 100 and never be sick if we cut out all plant products. There are some very weird claims, like carbs are the reason we sunburn and if you don't eat carbs you won't sunburn. Really it's just terminally online chuds who are still mad about their moms making them eat their veggies when they were 5. Although as someone noted above, there are other fad diets that latch on to the whole seed oil thing, including vegan and vegan compatible fad diets.