David Protein Bar review: Maximum protein, minimum calories — but is it worth it?

Protein bars are everywhere. But RXBAR founder Peter Rahal thinks there’s room for one more — David.

After selling RXBAR to Kellogg’s for $600 million, he teamed up with food-and-beverage founder Zach Ranen to launch David — a nutrition brand backed by Andrew Huberman, Ph.D., and Peter Attia, M.D., who also serves as the brand’s chief science officer.

David’s pitch? The most effective portable protein on the planet. David’s protein bars pack 28g of protein into just 150 calories. I grabbed a variety pack to see if the bars live up to the hype.

David, the new protein bars from Peter Rahal.

What makes David different?

Around the time of David’s launch, I was discussing protein bars with friends who are serious about bodybuilding. When I showed them David’s nutritional information, they were shocked: “How do they fit so much protein in such a small package?”

That reaction gets to David’s core pitch: “the most effective portable protein on this planet.” With 28g of protein in a 150-calorie bar, they’re targeting efficiency over everything else.

How David compares to other bars.

Notably, 75% of David’s calories come from protein — something the brand says makes it the most protein-dense bar on the market. Its blend of protein sources were also chosen to optimize both muscle growth and overall health benefits, from workout recovery to hair and nail strength.

A different philosophy than RXBAR

If you’re familiar with Rahal’s previous venture, RXBAR (with its famously minimal ingredient list boldly displayed on packaging), David takes a different approach.

Rather than following the “fewer is better” philosophy, David embraces science-backed ingredients designed specifically to:

• Maximize protein per calorie
• Keep you feeling full longer
• Maintain stable blood sugar

Simply put, David “designs tools to increase muscle and decrease fat.” Bringing this philosophy to life, David’s bars are scientifically engineered to deliver more protein with fewer calories using four systems:

• Protein system: David’s protein blend, consisting of Milk Protein Isolate, Collagen, Whey Protein Concentrate, and Egg White, provides a complete amino acid profile and scores a perfect 1.0 PDCAAS.
• Binding system: The binding system essentially transforms protein powder into a bar consistency for a better eating experience. Additionally, the binding system, which primarily consists of Maltitol and Allulose limits caloric impact and blood sugar responses.
• Fat system: To help minimize calories from fat, David utilizes a modified plant fat called EPG along with small amounts of traditional fats like coconut oil and cocoa butter to give the bars a fat-like texture without the calories.
• Flavor system: The David Flavor System gives David bars their taste and sweetness without adding calories or artificial sweeteners. The flavor system includes components like cocoa powder, salt, sucralose, and acesulfame potassium.

David bars are engineered to deliver the most protein per calorie.

When David’s ingredient-heavy formula sparked debate on social media pre-launch, co-founder Zach Ranen acknowledged that David prioritizes protein-per-calorie over whole food ingredients.

“Our mission is to create tools to increase muscle and decrease fat. The three most important things to achieve these goals are: eat sufficient protein, don’t eat too many calories, and keep blood sugar relatively stable,” said Ranen. “David will be a valuable tool for some (highly satiating, high protein, science-backed ingredients), and others may be less interested.”

So if you’re optimizing for protein, David’s high protein, low calorie formula might be exactly what you’re looking for. If you’re prioritizing whole foods, you might want to look elsewhere.

The taste test: Surprisingly good for 28g of protein

Let’s be real: No matter how much chocolate, caramel, or pretzel coating manufacturers add, most protein bars have that unmistakable whey protein aftertaste. And that’s OK, they’re not meant to be candy bars.

With that expectation in mind, I tested all four of David’s flavors: Chocolate Chip Cookie Dough, Blueberry Pie, Fudge Brownie, and Cake Batter. They’re sweetened with stevia and monk fruit extract, so David has no sugar.

Here’s my quick rundown on each flavor:

• Blueberry Pie: The standout. Surprisingly authentic with real berry taste — it felt like it was made from top-quality, real ingredients
• Chocolate Chip Cookie Dough: Classic buttery flavor with hints of chocolate
• Fudge Brownie: Most chocolatey, but with the strongest protein aftertaste
• Cake Batter: Sweet and true to its name, with genuine vanilla cake notes

(Since our review David has launched two new flavors: Salted Peanut Butter and Peanut Butter Chocolate Chunk.)

Testing David’s Chocolate Chip Cookie Dough flavor.

I’m not typically a fan of protein bar taste, and these won’t replace your favorite candy bar. But for what they are — post-workout fuel or a protein-packed snack — David’s bars are certainly enjoyable.

Price check: Value that makes sense when you do the math

At first glance, David’s sticker price ($3.25 per bar or $2.93 with subscription) is higher than many protein bars on the market.

But, here’s where it gets interesting. I did the math on a few brands that David compares itself to on its website: Built, Quest Nutrition, and Barebells. Here’s a breakdown of how much each gram of protein costs with each brand:

• David: $0.11/gram with one-time purchase (28g protein, 150 cal)
• Built: $0.15/gram (17g protein, 170 cal)
• Quest: $0.09/gram (21g protein, 190 cal)
• Barebells: $0.14/gram (20g protein, 200 cal)

David is actually the second most affordable per gram of protein, behind only Quest. But crucially, they pack that protein into 150 calories versus Quest’s 190, making David dramatically more efficient for those tracking macros with more of what you need (protein) with less of what you don’t (calories).

The bottom line: Is David worth it?

If you’re tracking macros and need efficient protein-to-calorie ratios, David protein bars stand alone. No other major brand matches its 28g protein at just 150 calories.

For anyone serious about fitness — whether you’re building muscle, cutting fat, or just trying to hit your daily protein targets without blowing your calorie budget — David is a game-changer. But if you’re focused on whole-food ingredients rather than macro targets, David may not be for you.

David isn’t trying to be everything to everyone. It’s a precision tool for optimizing protein intake and body composition, and on that specific mission, they absolutely deliver.

Fuel your gains with the most protein-efficient bar on the planet. Try David today and see the difference for yourself.