Well yes your bmr goes down as you lose weight Because it’s a function of your body weight to some extent

That said, a calorie deficit is the only real way a person will lose weight over time. The people who rebound are the ones who do extreme diets that they can’t sustain long term. Plenty of people have done slow and steady calorie deficits to reach a target weight then raise calorie to maintenance to maintain that weight

Yeah agreed the calorie intake must be at maintenance or above to avoid starving and losing weight continuously.

In terms of applications to humans, it seems like maintaining weight at a low-ish body fat % with resistance training to maintain lean mass results in the best health outcomes generally. Calorie intake has to be adjusted depending on whether you’re trying to lose/maintain/gain

What does 15% cr mean exactly? Is that 15% relative to ad libitum? Or 15% relative to maintenance calories?