The confusion is due to competing hypothesis that are both right-ish, the calories in calories out model, where all calories are viewed as the same equivalent, and the carbohydrate insulin model, where different foods are said to impact the hormones in a manner that equates to either fat retention or burning (simplified versions).
For me you cannot eat unlimited calories and not put on fat, but at the same time a 1000 calorie steak will not put on fat like 1000 calories of candy floss.
I experimented on myself with a heavy plant based (whole lower to mid carb) diet supplemented with meat / fish. Some meals were entirely plant based. Then I reversed this to more meat and fish and less low carb veg / fruit (all picture documented over 3 years), On the plant based diet I could get 42/41 HbA1c's with 3 hours of exercise per day, on the meat based circa 38 NHS (35.5 medichecks), again all picture documented.
Results might be different in your case, but low carb / keto enables meals to be close to conventional, with no or minimal new fangled food-like science experiments, untested over centuries in big populations.