I consider it the greatest failure of my education that nobody ever taught me to take, organize, and archive notes of any kind. I've only just begun that life-long project in the last few months. That said, I'll share what thoughts I can on each of the experiments you've specified. Maybe I can at least point a finger in the right direction for you. Cold Showers This is the one I tried the longest ago, and had the least observable results. In the end I quit because my only noticable result was that I ended up hating the idea of getting in the shower. I recall being left with the impression that it would probably take more cold exposure than showers, and over a time period of some years to produce the promised biological changes anyway. YMMV A quick look on Google shows that the current claims about the benefits of cold showers are far more varied than I remember. When I tried it, there was some talk about brown fat production as a result of repeated exposure to cold temperatures leading to more aggressive metabolism and better cold tolerance. As I recall, that conversation converged on a much stronger genetic component than environmental. Now I'm seeing talk of blood flow, pain relief, immunological benefits and more. To me, that smacks of snake oil, but provided you avoid hypothermia I don't think you'd be doing yourself any obvious harm to try. Be sure ahead of time what benefits you want to see and how you intend to measure them, of course. Sugar My understanding is that we've known for several decades that sugar is the enemy of good health and dentistry, so there should be plenty of literature out there. At some point the sugar industry made successful efforts to blame our problems on fat instead, eventually kicking off the low-fat/fat-free craze that still seems to have a stranglehold on popular American diet advice. I recall some reporting early in 2016 (I think) about the influence the food lobby has on our dietary guidelines. By memory, the current rec