When will the anti-fat brigade stop?
Still an insightful look into possible environmental cycles we've missed because we have devastated the North American bear populations for centuries.
Different types of fat have different nutritional effects and should be considered as different nutrients.
The health of a diet can only be considered as a whole, not bit individual contributors.
"Food A is good for me and Food B is bad for me" is not how health works.
Overly reductionist statement and as inaccurate as what you're arguing against.
There are absolutely foods we know to be bad for humans.
You're not wrong, but I definitely understood the parent comment's point.
Nutrition science has figured out some things to a high probability. It's still unsure and mystified by others. Don't throw the former out because the latter exists.
Your oversimplifying what I said.
As it happens, I generally favor a holistic approach to nutrition too.
I don't know what to think anymore...
Just eat a tiny bit of everything, and make sure you get regular exercise.
So you eat a little bit of it just in case it's essential for good health, but not too much of it in case it turns out to be bad in large quantities. Basically, you hedge your bets.
Wash and repeat for nearly every type of food that exists.
In order to fix errors and optimize, we need information. Trying to reason about a problem without adequate information is like trying to fix a bug when the only information you have is your QA folks coming back and saying "There's a bug."
A certain degree of fat is essential. People have been reported to actually starve on very high protein/very little fat diets.
Given plenty of carbohydrates, it is possible to survive long term on very limited supply of essential fatty acids as well as proteons.
Humans, feeding on primarily fat based diet get atherosclerosis very often. Best epidemiological/history research on that topic is done on Inuits where remains of children showed atherosclerotic plaques in the vessels - their diet, although not ketogenic, contained mostly animal fats and proteins. Other mechanistic studies proved that direct causal mechanism exists but the same thing happens also with sugary diet, or essentially any diet with a caloric surplus (highest effect of course with highly caloric diets or diets rich in cholesterol over long timespans).
Essential fatty acids (omega-3 and omega-6), on the other hand, are abundant in animal flesh (if we ignore plant oils). Human reliance on these sources definitely implies we are omnivores but with a certain complex twist.
Given the young age of nutrition science, lack of personalized methods, and flawed epidemiological studies (for example, epidemiological studies condemning meat and dietary cholesterol ultimately fail, on the other hand, studies showing that dietary cholesterol has no effect on basline cholesterol are methodologically flawed), a skeptic would conclude we still know little when it comes to long consistent living and the effect of diet on health. We do know a lot about intervention on sick people though. Practically any diet that is more healthy than a diet sick people practice works, best one being the one with highest nutrient to calories ratio (foods that have huge volume but low calories tend to have that characteristic and its mostly just plants - hard to overeat and create a caloric surplus), which is a plant-based diet. Still, it's questionable how this works long term (what's the source of fatty acids? where's B12 etc.).
Regarding dietary fat intake and risk of coronary heart disease (CHD) [3] following 80K women over 14 years, they failed to find a significant correlation between total fat intake and CHD. The linked summary discusses the relative risks of different fats (limit saturated, and completely avoid trans), but it essentially comes down to calories being replaced by carbohydrates. Note that foods labeled low-fat or fat-free do tend to have more sugar.
Another NHS study following 40K women over 8 years[4] showed only a weak correlation between fat intake and weight gain. The take away again is probably to care more about which fats. Unsaturated fats tend to be healthier than carbohydrates. Saturated fats tend to be more unhealthy, and transfats should be completely avoided.
[1] https://en.wikipedia.org/wiki/Nurses%27_Health_Study
[2] http://www.nurseshealthstudy.org/