I'm going to give him this one. Since it's nutrition I'm going to give my oversimplified layman explanation of it.

Dietary guidelines started during the margarine era of food when it was heavily marketed as a healthier alternative. People flocked to polyunsaturated fats like canola, rapeseed and sunflower oils which in modern day has been associated with a lot of health issues including weight gain.

There also is a correlation between saturated fats and cholesterol but that too is more nuanced now when looking at high density cholesterol (HDL) and low density (LDL). The body can get rid of LDL easily bit HDL clogs up the bloodstream. People eating more unsaturated fat tend to have unhealthier lifestyles and more importantly when you control for those factors such as drinking, smoking and not exercising and look at LDL numbers the correlation disappears.

I'm not advocating for processed meats like sausages, salami and pepperoni which is another can of worms. You should also definitely have some olive oil (mono unsaturated fat) that gets is that sweet sweet conjugated linolic acid.

So in short, avoid rape seed oil, sunflower and canola, especially if old or cooked at high temps.

Olive oil is amazing, as well as coconut oil.

Cow butter (watch the salt though), gee and beef tallow are in general a healthier options and way more nutritious. They're also more stable at higher temperatures like when frying on a pan and avoid a lot of health issues that come with polyunsaturated fats.

I'm going to reluctantly give this stupid lunatic this one.