It does provide Calories and protein, but Im not sure if it has all the essential vitamins and nutrients. What is the nature of their eating disorder? If they are older and have a feeding tube, we can consult a dietitian and formulate a liquid that can provide the amino acids, vitamins, minerals, and healthy fats their body needs.

Yes, many people live on liquid nutrition. Be sure the minimum caloric needs are being met though...basically the weight in pounds x 10.

A much better option is to buy a juicer and make fresh fruit and or veggie juice daily. Also make fresh broth daily (not from a powder) to increase nutrition! tastes way better too. And no synthetic food like substances in fresh food.