Protein Shakes and the Lap Band: Yes or No?

With respect to the lap band, there are two topics that will get me worked up every time I see or hear them. One is the need for "restriction"--by which the speaker or poster usually means a fill level so extreme that they are "forced" to stop eating, or they frequently barf up their food no matter how carefully they eat. This is way too close to an eating disorder in my mind to qualify as a viable long-term weight loss plan, and I don't believe the lap band was designed for this. (Remember, in eating disorder circles, they call their disordered behaviors "restricting.") I've posted about this topic previously in this blog, so I'll let this one go for now.

The second is protein shakes.

Many banded patients swear by their protein shakes. Sometimes, their doctors tell them to drink the protein shakes--usually doctors that ask their patients to take in more protein than is physically possible with a diet of solid food, protein requirements that are generally agreed to be appropriate for patients with malabsorption only, such as gastric bypass or duodenal switch. Other patients are told at some point by their doctors not to drink "liquid calories", but perhaps not explicitly told that protein shakes could sabotage their weight loss efforts--yet they are afraid of not getting enough protein, so they rely on protein shakes.

Protein shakes seem to be a controversial topic among bandsters for these and other reasons. The idea of protein shakes is very reassuring to a lot of people--it must provide "complete" nutrition, right? And it's easy, and some people enjoy the taste. They provide lots of protein for your nutritional "buck". Protein shakes are good for weight loss, right?

To look at this, we need to separate the way protein shakes work in the general population from the way they work in the banded patient. There are compelling reasons to think that protein shakes don't benefit the general population who do not have lap bands. (In this discussion, I'm not including people who have had other bariatric surgeries that utilize malabsorption. These patients have special nutritional requirements--usually protein supplements are a necessary part of their diets.)

Let me briefly add the disclaimer that I am not a doctor or a nutritionist. I am commenting on this topic as a registered nurse, a student nurse anesthetist who has recently studied the physiology of the GI system (tested last week on it, at the cellular level), a bariatric surgery patient, and a frequent consumer of scientific journals. These thoughts are not intended as the gospel truth but as food for thought, so to speak. I hope my arguments seem logical and provide a jumping-off point for more research and questions on the part of my readers.

The argument for protein drinks is basically this: protein increases satiety, so drinking a protein supplement will make one feel full longer. This is a controversial idea, in and of itself. There is good evidence that SOLID protein does increase satiety (which is the feeling that one is not hungry, or does not want to eat), although it is not clear why. Satiety is controlled by many factors--the pressure that a volume of food exerts on our GI tract is one factor, the kinds of digestive hormones and enzymes stimulated are another, the amount of carbohydrate present, our levels (and stability) of blood glucose, the amount of thermogenesis that digestion produces, etc. There is also good evidence that liquid calories--any beverage that contains calories--do NOT affect satiety. It appears that our bodies are unable to recognize the calories contained in a beverage and as such, we tend to take in calories from food as though we had never taken in the calories in our beverages. This is the main reason that many diet experts have blamed the increase in soda consumption for our increasing incidence of obesity over the past 30 years. Beverages containing primarily carbohydrates are most commonly blamed, but the same effect has been seen with beverages that derive most of their calories from protein, like protein supplement drinks. One mainstream media article about this idea that was widely posted in April 2008 can be found here. Here is a clip from that article:

Why do liquid calories fail to elicit the same response as whole foods? Reasons include:
-high calorie density
-lower satiety value
-more calories ingested in short period of time
-lower demand for oral processing [e.g. chewing]
-shorter gastrointestinal transit times
-energy in beverages has greater bioaccessibility and bioavailability
-mechanisms may include cognitive, orosensory, digestive, metabolic, endocrine and neural influences (human appetite is a complex thing!!!)

Last but not least, nowhere in our history have our ancestors had access to large amounts of liquid calories. Alcohol may have been around as far back as several thousand years BC, but even that is a blip on the evolutionary calendar of humanity.
As a result, our genetic code has never developed the physiological mechanisms to properly register the caloric content in liquids the way it does when you eat, chew and swallow whole foods.

So, those are some proposed effects of liquid protein on the non-banded person. How is this different in people who have the lap band? Any liquid calories defeat the purpose of the lap band. The band basically turns your stomach into a funnel: the band creates a top portion to hold food in, which slowly drips through the banded portion (the "neck" of the funnel) and into the lower portion of the stomach. Once the food is in the lower portion of the stomach, it is no longer helping you feel full--it's the pressure that the food exerts on the walls of that sensitive part of the upper stomach "pouch" that helps us feel full so we eat less. Any liquid will just go right through that funnel. So any calories taken that way will not help us physically feel any more satisfied, even if it's protein--because it seems that when you turn protein into a liquid, its properties of increased satiety are negated. It seems that protein keeps us satisfied longer because it's harder to digest, but when it is turned into a liquid it is basically pre-digested, so we lose that benefit.

Many banded people swear that their daily protein shake helps them feel full longer, and they carefully keep their calories very low and make sure not to eat more than a certain level. I'm not really sure how to respond to that. If it works for you, that's great. But it's something to think about if your weight loss tapers off or stops--are you sure you aren't eating more than you would be if you replaced that protein shake with solid food?

Obviously, any time you are required (by your doc) to stay on a liquid diet when banded, a protein supplement is a good thing to have in your diet. This would include the post-op liquid diet, after a fill (recommendations vary, but my doctors have told me to have only liquids for 24 hours after a fill), or when an esophageal or pouch dilation is suspected, or when your fill is too tight and you are going to go in for an unfill. But if you are on a regular diet, it's best to stick with solid food. If you are relying on protein shakes because you CAN'T eat (or keep down) solid food, you are filled too tightly, and you need an unfill, at least a small one.

That's one other big problem with having protein shakes as a regular part of a lap band diet--it can be hard to recognize when you are nursing a too-tight fill when you should really be slightly unfilled. Some people report going for months without realizing that they've been eating only soft, "easy" foods and liquids because they keep barfing up solid food, especially protein. Then that too-tight fill that has quietly converted their diet starts to show obvious symptoms--reflux or heartburn, pain, inability to keep even liquids down--and they find out that they've damaged their stomach or esophagus by not getting the fluid out months earlier. It's easy to be lulled into complacency because you're still losing weight. Nobody wants to be hungry, and that tight fill keeps us from eating much at all, without being hungry, so who would want to mess with that? But that kind of thinking can cost you your band in the long run.

More reading on protein and satiety: here and here.

This isn't really about protein per se, but I think it's an interesting blog post about how many calories are right for safe weight loss.

Reference for this article: Effects of food form on appetite and energy intake in lean and obese young adults. International Journal of Obesity. 2007 Nov (11):1688-95. Mourao DM, Bressan J, Campbell WW, Mattes RD. Department of Foods and Nutrition, Purdue University, West Lafayette, IN 47907-2059, USA.