My goal is to just consume the plenny shake because I am a lazy person and by not eating properly as I have been doing, my life just loses its structures. I workout so the the 120g protein intake isn’t a problem.
What’s better for the body to be consumed along the day: 3 x 800kcal or 6 x 400kcal?
I think the best thing is not to set a strict rule for yourself. You can have plenny however you like and whichever works for you.
The way I use it: if I feel like cooking something then I cook, if I feel like having plenny then I have that instead. It just turns out 90% of the time I happen to choose plenny. It’s just so much easier and like you I am lazy.
I just think once you make it into a rule it somehow becomes a chore to keep up.
For me personally I’d find it too much to consume 800 calorie shakes in one sitting, I don’t think I could do it. But if it works for you then there’s no reason why not.
Hey @Bruno! welcome to our forum 
We believe the amount of calories you consume per meal depends on how your body responds to the diet structure you establish. A high-calorie shake might be a bit heavy on your stomach. Or maybe not. The best way would be to set a day with 3x800kcal and the next day 6x400kcal. Then you can make a comparison and adjust.
We would love to know how it is going for you, and which calorie distribution you chose 