Month of 1-2 of powdered food meals a day
At start I had digestive problems, didn't feel satisfied, lacked energy and so on. Didn't like the smell, the taste, the texture of it. Well, Mana taste wasn't really that bad, but not appealing either.
After a weak or so I started liking Mana taste and got used to the texture. Played around with water amount as well, but in the end - went back to the recommended water/powder proportions.
I still don't like the bottle though - top part is too narrow: hard to pour in Mana without getting any powder around the bottle. And opening entire top just for drinking is very uncomfortable - inside of the cover is usually covered by mana liquid and droplets get here and there time to time. Check "Queal" shaker's cover diameter - it's perfect. Plus, secondary cover is easy to open for drinking.
Either way, product itself. Got used to it. Needed some time to adopt to slow releasing carbs and a much higher intake of proteins.
About digestive problems... I recommend getting something chewable to eat with mana/after mana, so your stomach knows it's time to start working - apple, nectarine, bread or even a chewing gum afterwards.
And texture... It's meh... But at least it's better then queal for example
(queal feels like drinking powder with water and artificial tastes - for example, their strawberry taste is like some medicine with added sweeteners to mask untastiness for kids)