Can you reference any metabolic ward studies to back up your criticisms of the calorie in calorie out "theory" in otherwise healthy (excluding BMI) individuals?

Can you reference any metabolic ward studies to back up your criticisms of the calorie in calorie out "theory" in otherwise healthy (excluding BMI) individuals? No doubt some people may have more efficient eg digestion of soluble fiber into SCFA based on their microbiota, but based on usual levels of consumption I would think this would make an absolutely trivial difference.