Key Takeaways
A quality protein bar should prioritize protein first, with at least 10 grams per bar and a calorie count that matches that protein load.A short ingredient list made from recognizable, whole-food sources can be an indicator of a higher quality bar that will keep you full. Many dietitians recommend RXBAR as the best store-bought protein bar because of its transparent ingredients with a complete protein source.
Protein bars have been everywhere for a while now, and they promise quick energy and easy nutrition. But once you flip a bar over and read the ingredient list, many start to look more problematic, whether it’s the added sugars, fillers, or ultra-processed ingredients that don’t actually keep you full.
To make sense of the many options out there, we asked registered dietitians what matters when choosing a protein bar, and whether any store-bought option actually checks all the boxes. After reviewing dozens of popular brands, three dietitians all pointed to the same bar as the only one they would consistently recommend. Here’s why this specific protein bar deserves a spot in your gym bag.
Kat Benson, RDN, LD, a registered dietitian nutritionist and digestive health expert for VNutrition
Destini Moody, RDN, LD, a registered dietitian nutritionist, board-certified sports nutrition specialist, and founder of The Athlete’s Dietitian
Jennifer Scherer, RDN, a registered dietitian nutritionist, certified personal trainer, and owner of Fredericksburg Fitness Studio
What to Look for When Buying a Protein Bar
Before you even get to brands or flavors, dietitians recommend familiarizing yourself with what actually makes a protein bar worth buying in the first place. Here are the main factors to consider.
Balanced Protein Content
It makes sense that you should consider the protein type and ratio before anything else. “You really want to look at the protein content,” says Destini Moody, RDN, LD, a registered dietitian nutritionist, board-certified sports nutrition specialist, and founder of The Athlete’s Dietitian. A protein bar should have at least 10 grams of protein, according to Moody, and the higher the calories, the more protein the bar should have.
If a bar is mostly protein, Kat Benson, RDN, LD, a registered dietitian nutritionist and digestive health expert for VNutrition, says it can be helpful to pair it with a carbohydrate source, like a piece of fruit, to make it more nutritionally complete.
Ideal Calorie Count
“If the bar is high in calories but not adding much protein, that’s a red flag that you are consuming calories from fats and sugars, which defeats the purpose of a protein bar,” says Moody. If you find yourself looking at something like that, Moody thinks it’s better that you just eat a small meal instead. “That way, at least you’re getting some nutrition out of it, and something that’s more satisfying rather than eating 300+ calories in four bites,” she says.
Minimal Added Sugars
You want a bar with minimal added sugars, ideally from whole-food sources, not syrups, artificial sweeteners, sugar alcohols, or highly processed additives. “Be wary of protein bars that are really just glorified candy bars with some protein sprinkled in. At the end of the day, you are eating them to supplement your protein intake, not necessarily to satisfy a sweet tooth,” says Moody.
Short Ingredient Lists
A short, recognizable ingredient list is a must for Jennifer Scherer, RDN, a registered dietitian nutritionist, certified personal trainer, and owner of Fredericksburg Fitness Studio. A good balance of protein, fiber, and healthy fats to support satiety is also a plus.
But Scherer likes to remind people that protein bars are a convenience food, not a replacement for real meals—they’re best used to supplement a balanced diet, not as a daily staple. “If you’re at a gas station or on-the-go and want a more whole-food option, I’d recommend skipping the bar and choosing things like a couple hard-boiled eggs, plain Greek yogurt, roasted edamame or nuts, or cottage cheese.” Whole foods will give you a better protein quality, fewer additives, and more satiety than from most bars.
The Healthiest Protein Bar
As far as what to buy in the protein bar aisle, there was a clear winner among the dietitians we consulted. “From a nutrition and health standpoint, I tend to favor whole-food–based protein bars with short ingredient lists,” says Scherer. “One brand I consistently recommend is RXBAR. I like that the ingredients are very transparent (egg whites, nuts, dates), the protein comes from a complete source, and there are no artificial sweeteners or fillers.”
These dense bars are especially helpful for athletes, who often need quick, sustainable fuel sources. “When I worked in college athletics, RXBAR bars were my favorite brand to come into the rotation at the fueling stations where athletes would stop by for snacks,” says Moody. “The transparent ingredient list that’s right on the front sent a strong message to athletes who needed to fuel their bodies with clean, whole protein sources, but who didn’t want to just eat boiled eggs and chicken breast all the time.”
Credit:
RXBAR
Moody likes that egg whites are the main source of protein, because she says eggs are known to be “arguably the highest quality source of dietary protein, with its rich amino acid profile and high level of digestibility when compared to other protein sources.”
The nutrient ratio is spot on, too. “I love RXBAR because they offer a balanced blend of carbohydrates, protein, and fat, which helps provide both quick and sustained energy,” says Benson, who also spoke on the minimal, recognizable ingredients, and the use of egg whites and nuts.
Best RX Bar Flavors
There are a handful of RXBAR options, and your favorite will likely depend on personal preference. One thing you can count on is that the bars are going to taste more like real food, but the texture is a bit chewier than other options on the market.
The winning flavor for dietitians is the Blueberry bar, because it’s a flavor that’s hard to come by. “To create a blueberry taste in most protein bars, artificial flavors are usually used, and it doesn’t take a strong palate to detect it’s not the real deal,” says Moody. “With RXBAR, however, you can visibly see the actual blueberries that give the bar its flavor, and it’s sweetened with dates rather than sugar alcohols or refined sugar.”
A couple of honorable flavor mentions:
“Chocolate Sea Salt is simple, satisfying, and not overly sweet,” says Scherer. “The peanut butter one hits the sweet-salty balance without being overly sweet, and feels satisfying rather than dessert-like,” says Benson.
