Dr. Mike, a rare YouTube doctor who is not peddling supplements and wares, and thus seems to be at the forefront of medical critical thinking on the platform, interviewed Dr. Amen recently[0]. I haven't finished the interview yet, but having watched some others, generally the approach is to let the interviewee make their grandiose claims, agree with whatever vague generalities and truisms they use in their rhetoric (yes it's true, doctors don't spend enough time explaining things to patients!), and then lay into them on the actual science and evidence.
[0] https://www.youtube.com/watch?v=J-SHgZ1XPXs