As convenient as they might be to use - Collagen-based protein supplements are not a good source of high-quality protein and should not be used as the sole source of protein intake in WLS patients.
Collagen-based protein supplements do not contain all of the amino acids that the body needs.
Collagen offers a range of benefits as far as convenience, gut health, wound healing and supporting healthy skin goes; so don’t throw it out completely, just make sure you are using it as a sideline, not a major part of your protein quota.
After liquid and puree phase, use your collagen as a boost, but don’t rely on it as a major source of your daily protein. Try to get your protein from food – it comes with many other nutrients as well.
Use protein supplements / meal replacements when you’ve not been able to meet your needs with food.