But many of those other products can be used as sole source of nutrition.
EG fortisip: http://www.nutricia.ie/products/view/fortisip
> Fortisip is a Food for Special Medical Purposes for use under medical supervision. Fortisip is a nutritionally complete, 1.5kcal/ml, ready to drink, milk shake style nutritional supplement, for the management of disease related malnutrition. Fortisip can be used to supplement the diet of patients unable to meet their nutritional requirements from other foods, or used as a sole source of nutrition. Fortisip is available in 200ml bottles, with a flexible straw attached, in 8 flavours: Neutral, Vanilla, Chocolate, Toffee, Banana, Orange, Strawberry and Tropical Fruits.
Ensure original: https://abbottnutrition.com/ensure-original
> For interim sole-source nutrition.