There’s no magic ingredient in Huel that makes your sleep better.
Rather than Huel making your sleep better, it’s more likely other food simply makes your sleep worse - so focus on eliminating all the typical culprits from your diet.
A good starting point would be chewing your food so much that it reaches the same consistency as Huel. This will certainly make the job of your digestive system easier, which will help your sleep. Most people have forgotten that they are supposed to spend considerable time chewing to break down the food.
Maybe the amount of calories you are consuming is the determining factor. Maybe it is also beneficial if your GI-tract is not busy digesting at sleep time. There are plausible causes for better sleep on a liquid diet. But of course you can still do a lot of things that worsen your sleep quality, for example too much screentime, too much caffeine etc.
You’re right insofar as it is not a clear liquid like water, and that its calorie density makes it necessary to count it as “food”. That does not change the fact that the texture is more liquid than solid.
What I mean is that Huel has the same consistency as any other food once you chew that food properly. That would mean that all food is liquid food, which makes no sense.
A liquid diet usually means any combination of milk, yogurt, pudding, ice cream, juices, soups, broths, oil, heated butter, alcohol, tea, coffee, sugar water, energy drinks, … Huel’s consistency & texture is far from any of these.
I have recently been looking into this as I too sleep much better after a couple of weeks using Huel, what I have learned:
Your brain is like any other organ and needs nourishing with the correct nutrition and your quality of sleep is directly affected by this. If you are now ‘feeding’ yourself and therefore your brain with the right vitamins and minerals it will help you sleep better.
There is a really good podcast interview with the guy behind Heights (Diary of a CEO Ep: 54), and while it is a big interview there is an excellent bit where he explains this and how he was treated for insomnia by being referred to a dietician, and they fixed it with his diet. Interesting stuff!
So all the good stuff in Huel is probably doing your sleep the world of good.
Sleep is affected by many factors: stress, nutrition, your activity. Most likely it’s nutrition that gives everything the body needs. I had the same thing when I switched to a lighter diet. Sleep improved, and so did my condition in general.