My point is that you would likely lose the same weight no matter what you ate, as long as you didn't overeat. There's nothing special about whipped cream, ground beef, and tomatoes. If you started at 290 lb (wild assumption) while eating 4000 calories/day, losing 49 lbs in 6 months by only eating 2300 calories/day is slow and consistent. But once you start approaching your target weight, progress will appear to slow down.

I don't think I could've sustained such an enormous caloric deficit (about 1,000kcal/day!) for as long.

"As long as you don't overeat" is like "assume a can opener." If we knew how to not overeat we wouldn't have an obesity epidemic on our hands. That's the whole reason "don't overeat" is not useful dietary advice whereas "eat lots of cream" is.