With all the heavily marketed supplements and protein bars out there, it’s difficult for many of us to navigate and discern what’s effective and what’s just hype. Are protein bars healthy, and do they really contain sufficient protein? What about the other ingredients? Is it good quality protein?
I’ve pondered many of these questions myself as I’ve chowed down on protein bars that taste great, and others that aren’t so palatable. Recently, researchers sought to investigate the quality of protein in these popular protein bars, yielding interesting results. Let’s look at the research.
The study
In a study published in the journal Scientific Reports, researchers analyzed the quality of the protein in 1,641 protein bars. Using data from the online consumer-generated database Open Food Facts, the researchers categorized protein bars into four groups of the most commonly used proteins:
- Plant only (rice and pea)
- Animal only (milk proteins)
- A mix of animal and plant (milk, egg, and soy)
- A mix of animal and plant (milk, collagen, and soy)
The focus was on the protein content, protein source, and nutritional composition. The researchers assessed the quality of the protein by simulating the digestion process in a lab to determine protein digestibility. The in vitro digestion simulation and Infogest method helped the study authors evaluate protein quality.
The results
The results revealed that:
- 81% of the protein bars tested had sufficient protein to be called “high in protein”.
- Despite this, protein digestibility ranged from 47% up to 86%.
- Many of the bars had low protein nutritional quality, which could negatively impact the amount of protein your body can absorb.
- In this study, bars containing only animal-based proteins (whey protein concentrate and casein milk protein concentrate) had the highest protein quality. The bars that had the lowest protein quality were the plant-based bars (rice protein isolate and pea protein isolate).
- The researchers found that the animal-based protein bars had higher fiber and protein content and lower carbohydrate, sugar, and fat content.
While 86% digestibility feels like you’re getting some bang for your buck, or should we say protein, the bars with 47% digestibility mean you could be only fully digesting about half of the protein.
The quality of protein
The researchers stated that this degradation in protein quality could be due to added ingredients, such as carbohydrates, fats, and fibers, which “might deteriorate the bioaccessibility of essential amino acids.”
Concluding thoughts
This study definitely gives us food for thought and hopefully prompts us to look more closely at the ingredients the next time we pick up a protein bar. While many bars might have “high protein” etched on the label, this doesn’t necessarily mean that you’ll be absorbing all of that protein or that it’s good quality.
More research is needed, but this study suggests that animal-based protein bars containing whey and milk proteins may be of higher quality, and your body may be able to absorb and use more of that protein compared to plant-based protein bars.
