Context: I struggle with insomnia and use blackout shades.
I’ve found blackout shades useful for when I’m not sleeping a schedule correlated with the sun (eg work at 4 am) or external artificial light (streetlamps).
My diet also changes in the Winter. I cut off caffeine at noon and restrict phone and screen time in favor of physical activities in the later afternoon. It takes about two weeks for my body to adjust fully to the changes, but then its fine throughout Winter. Even when I'm getting less sunlight because the sun is going down sooner.
I never knew how much your diet will affect your sleep and biorhythms until I started making changes. Even small changes can have big effects on your sleep cycles.
Hope that helps.
In Summer I tend to have more carbs and proteins, along with bigger meals for both lunch and dinner since I tend to exercise later outside then during Winter. The extra amounts in both for energy allow me to be active longer before the sun goes down.
In the Winter, I tend to reduce carbs and front load my day with them, so that in effect, by the time the sun goes down, my body is running down on their energy stores for the day. I also tend to reduce proteins and only increase them if I have a heavy day for example if I have both weight training and some higher impact cardio like hockey or indoor rock climbing or snowboarding.
In Winter I tend to have a bigger lunch and smaller dinner which helps to focus in the reduction in energy. Generally by the time 7 or 8pm rolls around, I can feel my body starting to tune down for the day and signals my body is getting ready for sleep. A hot shower usually puts me over the edge. I can get into bed and I'm out cold in a few minutes.
Hope this helps.
From time to time I'm looking into ketogenic diet and find it always inspiring how others manage carb and fat. I try to avoid carbs and if I eat them I always try to get my body moving, be it a light walk (so, not exactly practising full keto..). Main meal for me is dinner... I like how digestion and energy restoration is taking place mainly at night's rest. I don't experience problems falling asleep when giving my body food it needs. I'm usually not bothered by feelings of hunger til late afternoon (intermittent fasting so to speak, fat goes a long way..). Most important habit for good sleep seems to be "lay down, don't touch phone".. Hope this inspires, too :)
(eventual recommendation "the ketogenic bible, wilson/lowery")