The OP asked " So, is there any definitive thinking on this topic that might make future decisions easier. Maybe even a study...."

Short answer: No

Long answer: Several years ago I posed this exact question via an e-mail exchange with Dr. Tom Smith, widely regarded as one of the world's foremost experts on bear biology/behavior. I was clear that the discussion was restricted to only U.S. east coast Black Bears. Dr. Smith says that that a bear's desire to avoid you is greater than its desire to get your food. This is the logic behind the "sleep with food" group. However for this to work you must keep you food in your possession 60/60/24/7 (that's 60 seconds of every minute, 60 minutes of every hour, etc...). The logic also presumes that you minimize food odors (with odor barrier food bag liners) and maximize human odor (don't wash or if you do, don't use scented toiletries). Evidence to support this rationale is that bears are never known to go after food in the pack of a hiker while hiking, and that nuisance bear behavior is most likely learned as a result of poor storage of unattended food. Dr. Smith's response to my query was that based on the best research on bear biology/behavior, the logic behind the "sleep with your food" strategy is, in fact, sound are reasonable. HOWEVER he also said that while he knows many bear researchers who sleep with their food, based on his extensive experience, HE CHOOSES NOT TO, but rather advocates the use of other methods, the best of which are canisters and electric fences (there are lightweight fence systems for solo backpacking use). He also advocates ALWAYS having bear spray, not using guns, and ignoring conventional wisdom (much of which is not based on science yet easily available in on-line discussion fora). As for research specifically designed to resolve the food debate, I'm fairly certain that no one has done the definitive study, which would be to designate a large area where all people are required to keep their food on their person 60/60/24/7 and see if bears indeed learn that backpacker's food is not free for the taking. I also seriously doubt that anyone is willing to sponsor such a study in the foreseeable future.

This article does a good job of summarizing Dr. Smith's advice on hiking in bear country - entertaining as well as informative and well researched.
https://www.backpacker.com/survival/...ars-the-skills