While it's really great that we can get advice here on what kind of protein we should be taking, we don't always get the "Why." Or we may just get a "this kind of protein isn't good for you" sort of answer. I wanted to discover what was so "wrong" with proteins like casein that we couldn't take it. So I went a-researchin' and here's what I found out. (Oh and you vets may have already known this and so please feel free to read no further... this is sort of for those of us that can't get past page 10 of the forum posts and forget how to use the search function... and yes I am pointing this at me) Now bear in mind please that this is my opinion, i am not a nutritionist or a doctor. This is simply my understanding of what I am reading and the conclusions I have drawn from what i have been reading.
The reason bariatric patients are advised to use Whey Protein Isolate over other types of protein is that whey protein is the fastest absorbing protein. It contains the 9 essential amino acids we need daily. It also is less irritating to newly healing tummys because it goes through the system so fast. The bad thing about whey protein is that since it absorbs faster it is also used up by our bodies faster. Whey protein's effects only last 1 hour. So, in order to keep the effects of the whey protein going all day you have to be drinking whey protein drinks all day. Which is fine for those of us newly pre-op types who have to be drinking something all day anyway, but not so great for someone say 6 months out and just working on keeping water levels optimum. You don't want to be carrying a protein shake everywhere with you but if you only use whey protein you wouldn't have a choice. To get the optimum benefit you would have to keep drinking it.
Now about casein protein. Casein protein is found in milk just as whey protein is. But it's a slow-acting form of protein. Casein protein it takes approximately 3 to 4 hours to be absorbed into the blood stream and its effects last 4 hours as well. Now the problem is that, with our smaller tummies, the casein goes right through the sleeve before its benefits can be absorbed. Don't know about you but I have definitely noticed that it doesn't take 4 hours for my protein drink to go from mouth to booty. We just don't have that 4 hour window to get our protein absorbed.
From what I am understanding from my research so far, if you drink whey protein drinks during the day and then have a casein protein drink an hour or so before bed you are actually doing your body better than doing either one alone. The casein taken before bed has time to absorb because you are not doing anything to get rid of it right away. It's going to sit in the tummy and intestines for several hours giving it a better chance of being absorbed.
Collagen based protein is not a great choice for bariatric patients because it just simply doesn't have the essential amino acids that we need to survive. In other words, its just junk, pretty much like potato chips and soda. There's just not enough nutritional value in it to meet the high demands for protein that our surgery requires to keep us healthy.
Soy protein is an option if you are lactose intolerant but bear in mind that the isoflavinoids found in soy protein can cause issues regarding estrogen levels and that can bring on problems of its own. If you are not lactose intolerant the best bet would be to find a whey isolate protein you like and stick with that.
So which one is the best? From what I read, a combination of whey isolate and casein would just about cover all your bases.
Sources (in case you want to read these articles and figure out if I am way off base or not lol):
LaprascopicMD
LiveStrong
Obesity Action Coalition
CDC
Nutrition Express
Bodybuilding For Idiots
