Just a thought
Wouldn't eating nothing at all and just downing amino acid supplements with water work better?
Well (and this is the biochemistry undergrad background talking here), theoretically:
If the amino acids you took were pure essential amino acids, then theoretically, you could get away with eating less protein. Your body would use the EAA's to manufacture any non-essential AA's your body would need. Therefore, you wouldn't need as many calories from protein sources, since a few grams of EAA's can easily replace many grams of complete protein. Let's say the ratio is "one gram of EAAs replaces 5 grams of complete protein" (and don't take my science as exact here...I can't remember the ratio).
Then, theoretically, if you thought you needed 100 grams of protein per day to achieve your goals, you would only need 20 grams of EAA's to do the same thing. In which case, you could save yourselve from eating 80 grams of protein (the 5 to 1 ratio). And that amounts to 320 fewer calories you'd have to eat (80 grams x 4 calories/gram = 320 calories).
Now, that'd be a miserable existence. But you could do it, and I think the math would work and theoretically, it should work. But that would really need to be applied to see if it bears out.
In patients fed parenterally, it's not uncommon to dose with saline, glucose and EAAs. But that's in extreme cases.
Not sure why you'd do it, but it's worth a shot if you like experimenting. I'd love to study it, but I'd never do it myself. I like chewing food.
Now, there are reasons why it won't work.
You simply can't expect pure EAA's to replace a complete protein source. EAA's are just that: pure EAA's.
A piece of steak also contains creatine, essential and non-essential fats, minerals...there's just too much going on with a piece of food to compare it. I think in the long run, you'd probably wind up with micronutrient deficiencies, unless you made a concerted effort to get those micros from other food sources.
So theoretically, it's do-able. But in the real world, there's a good chance for malnutrition over the long-term, and general unhappiness and malaise in the short-term.