FAQ: Are You Limited to the Amount of Protein You Can Absorb?

My dietician told me you can only absorb 20g of protein at a time, should I limit the size of my protein shake? Is eating all this protein at once a good idea?

Lots of dietitians and nutritionists *believe* this is true, when it is actually not true at all. The fact is our body sucks up the amount of protein that it NEEDS at any given time - it doesn't turn off or automatically STOP at 20g or 30g or 40g. And no, a single serving of protein (whether it’s 20 or 40 or even 75 grams) will not damage healthy kidneys. Thats not how the human body works!

Several years ago, two of our lovelies, Dr Joselyn Postar-Baum RN & Debby Olsson RN, attended the American Society for Metabolic and Bariatric Surgery course on Nutrition in Philadelphia on behalf of Bariatric Eating. In addition to being brilliant nurses with multiple advanced degrees they are also long term and very successful bariatric post ops.

There was a presentation of a study that dispelled the often repeated tidbit that protein absorption is capped at a maximum of 20 grams at one time. In fact, this study showed that there has never been a study that has reported the 20 gram of protein at one time fact. Yep, the study is a myth.

In any 24 hour period, you can absorb as much as 300 to 400 grams of protein. This is not recommended because there are complications associated with this high of intake. The high end of protein per day recommendation is 100 to 120 grams. Absorption of protein relies on many factors including - source of protein, length of the Roux limb in gastric bypass, size of sleeve or pouch and your intake of micronutrients.

What your dietician probably meant for you to understand was that it's always better to spread out your protein. It wouldn't benefit you to drink one giant shake with 80g protein, but much better you drink four protein drinks, each containing 20g protein. That is a great way to ensure they are getting sucked up and are doing your body good.

The human body is full of variations for different circumstances - sometimes your body needs more protein such as RIGHT after surgery when building materials are needed for repairing tissue damaged during your operation - sometimes less, as in middle of the day when you are sedentary at your desk.

Maintaining even balanced portions is best... thats why FIVE SMALL MEALS or 3 Meals plus two planned smaller protein meals are fairly universal in bariatric plans as well as our Inspire Diet plan to address Bariatric Regain.

This is a GREAT question! We are happy to be able to answer it.