Has anyone had experience with needing to take amino acid supplements because most of the 'complete' protein powders they are unable to have? I'm pre-surgery but allergic to the whey protein in milk, and in trying some other protein powders, found that soy, pea, and egg protein powders cause digestive havoc of the TMI variety. I've found that collagen protein powder and hemp protein powder I am perfectly fine with, but I know collagen is missing one of the essential amino acids and hemp protein while complete is low on the essential amino acids. The dietician seem flustered that I can't have whey protein and I've not been able to find anyone talking about using amino acid supplements to make an incomplete protein complete. Also totally open to other suggestions for protein in the weeks pre- and post-surgery while on the liquid diet.

Actually after surgery & when the constipation begins you may appreciate some of the digestive issues - LOL!!

After surgery I really struggled with the shakes - the taste & texture were awful. I powered through with one, diluted an extra 50%, in the morning & then had soups. Broths, consommés, cream soups, are all good. Bone broth is best though I found it too salty.

Have you explored the possibility of making your own smoothie using a vegan milk & a vegan yoghurt (blend to very thin consistency with extra milk or water)? Not sure the protein content though. Do you know what it is in the whey free protein powders that cause the digestive issues like the guar gum or xanthan (insoluble fibre)?

Can’t help with the amino acid supplements sorry.