Many people have the notion that vegetable oils are healthier than animal fats as well (that's not generally true from what I can tell, but people believe what they will), so they might be likely to use more of it than people who might believe animal fats should be moderated. It's hard to tell because I'm working from popular western ideas around nutrition, and this is data from China. I'm not sure if people there think animal fat should be moderated or that plant fats are healthier – it could be the opposite, or barely a consideration at all.

Another factor could simply be cost. Maybe people who use plant oils use more because it's cheaper, or vice versa.

I think the analysis should ultimately reflect in its conclusion that more research is required because the data isn't sufficient to draw meaningful conclusions. I also find this concerning:

"Our study found that cooking with lard/other animal fat oil is more beneficial to cardiovascular health in older Chinese."

On balance, cooking with refined oils is not shown to be beneficial to any otherwise-healthy population; there is no advantage to cooking with lard, and rather, there is an advantage to replacing those calories with sources of higher quality nutrition in general.

While plant vs animal fat is indeed controversial, it is not controversial that cooking with (especially frying, baking, broiling, grilling) high fat foods is not very good for people. Though the analysis indicates that animal fats may confer lower risk, it's fairly clear that high refined-fat diets generally do confer higher risk than diets with lower fat and/or fats from whole foods.

It seems we shouldn't worry about which fat to cook with so much as how to cook with less refined fats in general. If we consume reasonable amounts of fat (that is, far less than we tend to on average), the question of which type to cook with becomes far less pressing and relevant.

I'm not saying "never eat saturated fat" or "your high-fat cuts of meat are killing you"; I'm specifically saying that through many years of looking at this kind of data, I've never once seen anything indicating that cooking with refined oils is a good idea, ever. Get it from whole foods first, whether it's a plant or an animal, and you'll fare better (according to heaps of the best quality studies we have, ranging back a half-century).

So, that's why I'm not crazy about this analysis.

Apologies if I missed something. I was reading it on my phone, and I'd gladly be corrected. I don't want to put down a good analysis because my eyeballs aren't working.