And a lot of people are terrified of consuming 5 grams of fat, but think nothing of consuming 400 carbs in the form of bread, pasta, and sugar. I'm advocating an approach based on whole foods, less sugar, carbs only from wholesome sources like oatmeal and whole grains. I'm just trying to say people focus too much on fat.
tl/dr; Guy eats 5800 kcal every day of fat for 3 weeks, gains 1.3 kg and loses about an inch from his waistline, same guy eats 5800 kcal from carbs every day for 3 weeks, gains 7.1 kg and about 10 cm on the waistline. Exercise is supposed to be the similar in both cases.
Yes, it's just an anecdote, but an interesting one. And imho a reason to be a little humble about the things we think we know about how the human body responds to different kinds of foods. More research is needed.