How/what are you basing your "sweets/desert impacts my sleep more than a drink or two" on?

I was waking up an hour or more before the alarm (so waking up <=6AM with 7AM alarm). And I thought my sleep was good - after all Fitbit sleep score was 80-85.

Then after stopping alcohol I started sleeping longer. Specifically waking up later, at least for the first few weeks.

Seemingly alcohol was causing earlier waking due to spiking cortisol too early.

While waking-up time took a few weeks to recalibrate. Already 2-3 days after stopping alcohol - Fitbit was showing clear improvements in actual sleep quality metrics - HRV was increasing and RHR/BR were decreasing.

And now my "bad nights" have Fitbit sleep score of ~85, and it's regularly 90+.

Lab results are night and day - e.g. CRP was 20 (>5 signals inflammation), just few weeks after stopping alcohol it was ~10 while I was having cold/fever, and now it's <1.

The biggest/hardest problem for me was that after stopping alcohol, my sweets intake increased, especially in the evening. I was doing almost no carbs during the day, and then in the evening ... I guess brain was lacking some easy dopamine that it would previously get from alcohol... I would crave sweets, ice cream ...etc.

It took almost 3 months to be able to stick with strict keto diet. I'm finally doing <=20 gram of carbs because from past experience - any higher and I have a hard time limiting carbs to say just 50 (which would still be low carb/keto).

It's based on the sleep tracking data my fitness watch gives me, but also just based on how I rested I feel the next day, since I know there's limitations to the data quality a watch can give you.

I have noticed the early waking thing with alcohol, but for me that's never really an issue after a drink or two - only at higher consumption levels do I really have that problem (along with the bad dreams/nightmares that many have after drinking).

One other thing I've realized while experimenting with this is that I tend to be sleep better when I'm cooler - so anything that would raise my body temperature has a huge negative impact on sleep quality. This could be large amounts of alcohol, or it could be lots of sugar in the evenings, or a salty/starchy meal late in the day, etc. This seems to be a more important variable than anything else I've observed.