That may well be true if you need to be persuaded to exercise and eat right.

OTOH, if you don't need to be persuaded and just want information on how best to go about doing it, then I think it makes little difference where the information comes from as long as it's of reasonable quality.

Maybe for you, but that model clearly doesn’t generalize, or dieticians and physical trainers would only have success stories to point to.

The specific example was indeed a poor one since we have extensive data on that, and even high-touch non-surgical interventions involving hours per week from multiple specialists (read: incredibly expensive) with very-willing participants have proven a lot less effective than one might hope (somewhat effective! But only moderately so, which ain't enough given the price tag). Docs saying "eat better and exercise" at an annual check-up has basically no effect whatsoever.

Turning dozens to hundreds of decisions per week for which the correct decision must be made in nearly every case, into a single decision per week for which the correct choice must be made, has proven wildly more effective than any of that (I mean glp-1 agonists).

My Watch tells me I need to stand up and walk around and that I should do some more exercise or walk further than normal today.