When used strategically, protein snacks can be a great way to help you hit your daily protein goals. Most nutritionists and trainers agree that whole foods should make up the bulk of your intake, but adding a protein shake or bar to round out your day isn't going to hurt. In fact, many people swear by these ready-to-eat or drink items to stay on track. That said, not all of these products are created equal.
In fact, a recent analysis of 1,641 protein bars found that the quality of protein in most bars on the market is far from ideal for building muscle. For the study, researchers analyzed the protein content, source, and nutritional quality of widely-available protein bars, using data from OpenFoodFacts.org.
The bars selected were broken up into four categories based on their protein sources: plant only (pea and rice), animal only (milk proteins), mix of animal (milk and egg) and plant (soy), and mix of animal (milk and collagen) and plant (soy).
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To assess protein quality, they used in vitro digestion simulations (a process which mimics the digestion process in a laboratory setting) and calculated two key nutritional indices: DIAAS (Digestible Indispensable Amino Acid Score) and PDCAAS (Protein Digestibility-Corrected Amino Acid Score). Both of which test amino acid composition and digestibility.
Although 81% of the protein bars analyzed were considered high in protein, when the protein sources were processed into bar form, digestibility dropped drastically (to as low as 47%).
The highest scoring protein bar was the bar containing only milk proteins (whey and milk protein concentrate). However, the content was still relatively low in comparison to the protein in its isolated form.
According to the study, "the low numbers are most probably due to application of lower-nutritional-quality proteins (such as collagen) and of other ingredients such as carbohydrates, fats and fibers, that might deteriorate the bioaccessibility of essential amino acids."
So while many bars are marketed as "high in protein," their actual nutritional quality often falls short, especially if your goal is building muscle. Next time you need a protein boost, you might be better off reaching for a high-quality shake or a whole food alternative.