Those refined oils aren't handled in the same way the healthy, natural ones are so it contributes to the metabolic damage.
It's not really a battle between processed and unprocessed. It's just simple math. Oil and sugar pack a lot of calories in a very small package.
We eat multiple times every day. We have the entire variety of food at our disposal multiple times every day. I can have a feast for every meal. Most people eat like royalty of the past. This is new. Most of us live post-scarcity. We're having a hard time adapting because our instincts and behaviors come from times of scarcity.
https://www.health.harvard.edu/blog/theres-no-sugar-coating-...
https://www.webmd.com/diet/news/20120626/all-calories-not-cr...
"That’s just not what the unbiased studies have shown. Looking only at calories ignores the metabolic effects of each calorie; the source of the calorie changes how you digest it and how you retrieve energy from it."
And there's also the point that calories that "leave the body" aren't really calories consumed.
So if a portion of the raw caloric value of something gets expelled through waste because we aren't really able to process it in time, then it's not really a consumed calorie.
A large portion of the rage against Calorie In Calorie Out is really about our ability to accurately measure calories in any fashion.
We make estimates about the caloric value of a food because the means by which we can measure it is destructive. And we assume that every calorie that enters our body stays there until used as energy. Which may not be true either.
And the WebMD article specifically mentions that the low carb group was essentially stressed the whole time. And it's a study of 21 young people who lost 10% to 15% of their body weight. That's 10 - 20 pounds of an average person.
This guy lost weight eating 1800 calories of twinkies a day. https://www.huffingtonpost.com/david-katz-md/chewing-on-the-...
I think this is a much more interesting experiment as twinkies are roughly uniform. There may be some caloric variation, but none so great as to be relevant. Plus, the overs and unders should average out.
So watching the caloric content of your food is always a good idea if you're looking solely to lose weight. But instead of trying to figure out how many twinkies you can eat in a day, we should be trying to find out which foods we can eat a lot of and still maintain a caloric deficit.
If you want to lose weight then simply counting calories and eating less is an effective strategy.
Not that I'm advocating a lettuce only diet. But as I acquire more and more information about how we eat, what we eat, etc, I've become of the opinion that we do have way too much salt, oil, and sugar in our diets. We can even cut down our meat consumption greatly with no ill effect.
We're survivors who haven't had to survive for centuries now.