To my understanding, a lot of people consider protein bars/shakes unhealthy. They are processed, often sugary, and contain chemicals that are probably used to create gym mats.

I eat protein bars regularly. The ones I typically eat are called Pure Protein or Balance bars. They are relatively low on sugar and calories in general (obviously there are artificial sweeteners used), provide around 20 grams of protein, and provide many other vitamins that are probably missing from my overall diet.

My question is not really whether or not processed foods are healthy to eat (Natural > Processed > not eating), but rather if the human body utilizes the protein and vitamins contained in them. Will 20 grams of protein from a protein bar have the same effect as 20 grams of protein from organic grilled chicken? Are the vitamins they contain (which I assume are similar to taking a multivitamin) effect the body in the same way as if I ate nothing but organic fruits and vegetables?

I have attempted to look this information up myself, but find that the answer is often pretty biased. A quick search shows me numerous articles that use vague statements like "studies have shown", or refer to links to other organic food/herbal remedy sites.

What I am looking for is some sort of concrete, scientific proof that protein/vitamin supplements are either less effective than natural foods, or are flat out unhealthy for you.

  • My knee jerk reaction was to answer this, but you are asking for concrete, scientific proof. I also could not find any real studies. I think you will find that it is going to depend on how the protein (for example) is processed to get it into the bar. This will vary from brand to brand. My opinion (which is why it is here instead of in the answers section) is that "real" food will be processed better. – Joe Ruder Mar 10 '16 at 14:41
  • So, studies showing that they are either just as effective or even better are not okay ;-)? (I suppose they are, but your question is worded as if that wouldn't be an acceptable answer) – YviDe Mar 10 '16 at 18:03
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    @YviDe I would be thrilled to see a study showing that they are just as effective if you can find one. That would answer my question nicely. I guess i worded it the way I did because general consensus seems to point to nutrients from food being better than nutrients from bars. I was looking for someone to prove that so-called "common knowledge", but if you could prove the opposite I would be very happy. – bsayegh Mar 10 '16 at 20:44
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    nutrients from food are better than from bars because of what comes along with them. Vitamin C from an apple comes with fibre and assorted phytonutrients that may not have been studied. From a carrot it comes with a different set of phytonutrients, and Vitamin A. From a bar, it's just what they chose to add, which might not be everything you need. Ditto for a pill. I doubt anyone will conclude you don't get the stuff the bar has, just that food has more stuff you're likely to need. – Kate Gregory Mar 10 '16 at 22:46
  • I’m voting to close this question because diet and nutrition questions are off topic here unless they're directly related to medical treatments. – Carey Gregory May 28 at 5:30

What you are asking about is called bioavailability, which is the term for how much of a consumed substance is actually taken up by the body, and bioequivalence, which is about whether two products are used the same way in the body.


For protein, bioavailability is also called Biological Value (BV). The BV of an egg, for example is somewhere around 93 (see column 5). For cooked chicken, a bit over 70.

It's hard to find sources for protein powder/shakes that don't seem biased (being from the manufactors of the protein, or bodybuilding sites), but here's a study from the Journal of Sports Science and Medicine: Protein - Which is best?. It uses an adjusted scale, where a whole egg has a biological value of 100. In that scale, since whey protein has a higher BV than whole egg, it comes out as 104. Soy protein and casein have BVs in the mid-70s, a bit lower than beef.

As for whether they have the same effect, well, what's different betrween different sources of protein is composition. Proteins are made from building blocks called amino acids, of which there are 20 in food. Many of those can be converted from one to the other or made from other things we eat, but 9 amino acids are called 'essential' and have to be eaten. Different foods, including protein powders differ in what amino acids they have. Usually, protein powders will contain these. How much they contain will depend on the product.

Keep in mind that no source of is 'perfect' in that regard, either. A bean does not have the same amino acid composition in its proteins as a human body does. Neither does whey protein. Deficiency in essential amino acids isn't pleasant, but it is rare in people who aren't generally malnutritient and consume enough protein overall, from more than one source.


Basically, a lot of the same applies for vitamins. They aren't perfectly bioavailable when digested from food or from a multivitamin, sometimes one is better, sometimes the other. Answering this for all vitamins is way too broad, and it probably also depends on the product. The paper Multivitamin and multimineral dietary supplements: definitions, characterization, bioavailability, and drug interactions goes into a few of the problems and general concepts.

For example, it looks like the bioavailibility of folic acid taken up from dietery supplements is higher than that from food, and especially outperforms spinach and yeast (warning: low number of subjects in study...). For vitamin C, Synthetic or Food-Derived Vitamin C—Are They Equally Bioavailable? summarizes:

In contrast, all steady state comparative bioavailability studies in humans have shown no differences between synthetic and natural vitamin C, regardless of the subject population, study design or intervention used. Some pharmacokinetic studies in humans have shown transient and small comparative differences between synthetic and natural vitamin C, although these differences are likely to have minimal physiological impact

And goes on to say:

Although synthetic and food-derived vitamin C appear to be equally bioavailable in humans, ingesting vitamin C as part of a whole food is considered preferable because of the concomitant consumption of numerous other macro- and micronutrients and phytochemicals, which will confer additional health benefits.

So whole foods are preferable, but the vitamin C that you get from the supplements itself isn't any better or worse than the vitamin C an apple contains, and certainly isn't unhealthy.

For some people, getting all vitamins they need from their diet is either impossible or very hard (vitamin D and iron deficiencies are rather common) and that's where supplements like the protein bars you use come in. As pointed out by Atl LED in the comments, though, for vitamin supplements to work it's important to take care of how the multivitamins need to be taken. If they need to be taken with food for maximum absorption, that's important or else you won't get the full benefits.

If protein bars are judged as 'unhealthy' it should be because of things like their sugar content, but it's certainly not true that the proteins or vitamins in them are unhealthy or that we can't use them at all.

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  • This is a fantastic answer. I wasn't aware that there was a metric for how much of a nutrient is used by the body. That gives me a lot to work with for future research. I really appreciate your thoroughness! – bsayegh Mar 23 '16 at 18:01
  • @bsayegh thank you! I might like researching a bit too much ;-) – YviDe Mar 23 '16 at 18:05
  • I think this is an excellent place to out that most vitamins must be taken in the middle or end of a meal to maximize bioavailability. The number of families I run into missing that is astonishing. Also very few people are able to meet micronutrient recommendations w/o a basic multivitamin, even when intentionally following a balanced diet. – Atl LED Mar 23 '16 at 23:57
  • Also, on the concern that some may view my comment to mean some brands of vitamins don't have to be, I mean specific nutrients, chiefly soluble acids (folic acid, vitamin C, etc) don't get as much of a boost by being taken with a meal so they can be taken alone. As a general statement, however, it's better to take them all with a meal. – Atl LED Mar 24 '16 at 0:01

Protein shakes and bars can actually be EXTREMELY healthful, but you have to get the right ones. You will find the best at health food stores, not general vitamin stores. Steer clear of whey as there are negative aspects of that and I along with others suspect its popularity is only due to industry trying to find a way to profit off of whey, which is left over from processed animal foods, namely greek yogurt, in such an excess that it is very hazardous to the environment. So, not only do they have to find a responsible way to get rid of all this excess whey, but they try to find ways they can simultaneously profit off of it. I personally noticed seeing a lot of whey supplements as greek yogurt became popular so I feel that's something to take into account.

You want pure, preferably organic ingredients with no hidden msg or other unnatural ingredients. And you want one that is WHOLE FOODS BASED. That is very important. Raw is best. I highly recommend Garden of Life's Raw Fit as it has every essential amino acid, probiotics, antioxidants, vitamins and many minerals. 1 scoop provides 28 grams protein and 90% daily value of magnesium which the western world is extremely deficient in.

Same goes for bars... look for bars in health food stores. I would look for seed and nut bars as opposed to very processed bars with long lists of ingredients.

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  • This does not in any way answer the question, which is about digestion of protein bars and not about whether to use them or which ones to use. – YviDe Mar 14 '16 at 7:51
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    This is like what I would read off of someone's health blog. I want hoping for sources to studies that have scientifically proven that one method of ingesting nutrients was better than the other. I don't even need a link, just tell me about it and ill look it up. I don't think this answer provides that information. – bsayegh Mar 14 '16 at 13:42

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