I recently tried giving up sweets for two weeks. In early December I attended a conference, which meant a break from my normal routine. After a few days I realized this was the longest I'd gone without eating any sweets in 2-3 decades. After getting home I decided to go a bit longer to see if anything interesting happened. Would my focus be better? Better sleep? Would I feel healthier? Would I stop missing them?

While I started by accident, if I was going to keep doing this I needed a system: what counts as a sweet? I decided to use the same system we use with the kids: no desserts or other things that are about being sweet. The sweetest thing I was still eating was probably bran flakes for breakfast, at 6g per serving. [1]

I did pretty quickly stop feeling a drive to eat sweet things. Which was kind of neat: normally I do feel compelled to eat something sweet after lunch and again after dinner. But I didn't feel better: the main change I noticed was that I had less energy in the afternoons and maybe made more mistakes at work. I also think I was a mildly worse Go player, though any comparisons here are going to be unreliable since I'm just playing one other person (my dad) over and over.

My main sweet consumption is ganache (a couple spoonfuls from a jar), usually after lunch or dinner. Perhaps the fat is helpful here? Or maybe I'd become dependent on the caffeine in the chocolate? Probably not, though: I'm guessing the amount I was eating came to ~15mg of caffeine, so only 8% to 15% of a typical coffee serving. Claude guessed this was too low to be distinguishable from placebo, but I haven't looked in the literature to verify.

When I restarted sweets I noticed pretty quickly that I felt better in the afternoon, my Go playing was better, and also that I was sleeping slightly better. [2] I didn't notice any downsides. I suspect some of this pattern is that most sweets I eat (primarily ganache, followed by other products high in cream) have a pretty high ratio of fat to sugar? I do know that when I eat mostly-sugar sweets I don't feel great afterwards.

One place where I thought I might notice a change was weight, but that's a bit confusing. I lost ~3%, mostly after restarting sweets. I don't know what to make of this; it's the opposite direction of what I'd expect to see. But 3% is also pretty small, so I'm not going to read much into this.

My main takeaway here is that the way I've been eating is fine, and I'm not planning to change anything other than bringing some with me next time I travel to a conference.

[1] This is higher than would be ideal. I should see if I can find a lower-sugar brand.

[2] Though still not great: since having kids (or just getting older) I haven't been able to sleep anywhere near as well as I could in my mid 20s and younger, even though my kids don't wake me up in the night anymore. Mainly I wake up ~1hr before my body feels like it's had enough sleep. It's nice to have the extra time, but I'd rather have the sleep.