The carnation instant breakfasts are good, but there are alot of different ones, and they are not the only nutritional supplements offered by Nestle.
The Carnation Essentials Breakfast Originals is the drink lower on protien (5g) higher on carb (27g). It isn't unhealthy in general and for many ould be a good kickstart for the day...just not for VGSers...
Carnation Essentuals Breakfast Originals No Sugar Added Ready-to-drink-bottle in Rich chocolate (no other flavors in the ready to mix bottle) have (13g) protien and (16g) carbs. You could add a scoop of unjury flavorless to this and add 20g protien and 80 calories. Which would bring the calories to 250, and 33g protien.
I am not a Nut, nor do I play one on TV, but:
The carnation breakfast is different than the almost pure protien drinks supplements - they do have some carbs and a little fat - but compare the labels, they also give you alot of your nutritional needs - the protien drinks do not. I am not an expert on VGS (yet, lol) but I know we cannot have the carbs this includes at first, but later on we are going to need healthy amounts of fat.
Your body does not use any one single nutritional component in a vaccum - they all rely on each other. There are things we need beyond nutrition too - we need daylight for several of our Vitamins to work correctly, and some vitamins will not be able to work correctly without others vitamina and trace minerals, etc...sleep is so important!
About the protien - I am not seeing this mentioned in alot of places - it is very important we get protien, but if you arent exercising once you can - not (just) cardio, but also muscle retention and or building exercises - that protien is not going to provide the benefits you need it to. You will lose muscle if you do not exercize - and you will lose more hair than you would have otherwise (the last one is just a hypothesis for now but there is clinical evidence to back it up).
I have faught with nutritional issues with my Mom my whole life - she suffered severe head trauma when I was 9 that left her with almost 80% memory loss and among other things it affected her metabolism and soon thereafter she began to have nutritional issues also. To make a long story short I have spent 30 years or so trying to understand my Mom's malnutrition issues. That is also one of the reasons I avoided the full bypass.