We tried 12 of the most popular protein bars on the market - this is the only one worth buying

Weight: 60g

Protein: 20g

Calories: 220

Sugar: 0g

Carbs: 25g

Fats: 7g

Review: I'm instantly skeptical when I see it says 0 grams of sugar in bold on the front of the wrapper. My first thought is, if there isn't sugar in it, they're probably replacing it with something much worse.

Sugar is replaced with 20g of sugar alcohols. The offender here is Maltitol – it's 90% as sweet as sugar, but it can claim to be sugar-free despite replicating some of the harmful effects of sugar and causing spikes in blood sugar.

The bar is high in protein but has a bitter aftertaste.

Weight: 50g

Protein: 15g

Calories: 210

Sugar: 17g

Carbs: 22g

Fats: 7g

Review: This bar is stuffed full of artificial ingredients and sugar, which makes it seem like there's no real advantage to eating it over a chocolate bar. Its redeeming feature is that the protein content is pretty high, and it's affordably priced.

Weight: 45g

Protein: 12g

Calories: 170

Sugar: 15g

Carbs: 22g

Fats: 4.5g

Review: This bar has a lot of added flavoring and ingredients in its yogurt coating. It tastes sweeter than a candy bar, but this sweetness successfully disguises the chalky taste of the filling.

The protein in the bar comes from its soy protein isolate ingredient, which is a heavily processed version of soy.

Weight: 68g

Protein: 11g

Calories: 260

Sugar: 19g

Carbs: 40g

Fats: 7g

Review: This bar has a lot fewer ingredients and they are mostly organic, which is reassuring. But hidden amongst this is soy protein isolate, a heavily processed format of soy.

It looks a lot like a pancake, but the dusty aftertaste reminds you that it definitely isn't.

Weight: 68g

Protein: 20g

Calories: 280

Sugar: 22g

Carbs: 29g

Fats: 10g

Review: With almost double the amount of protein (though it is soy protein isolate), fewer carbs, and a similar amount of calories and sugar content, this is definitely a step up from Clif's energy bar.

That said, the sugar content is high compared to other bars, and the taste is definitely stronger (and not in a good way).

Weight: 45g

Protein: 4g

Calories: 210

Sugar: 16g

Carbs: 28g

Fats: 11g

Review: Lärabar is somewhere between a protein bar and an energy bar, which means it has a lower concentration of protein than the other brands.

For this reason, we ranked it a bit further down the list.

But based on taste, ingredients, and cost only, it was a winner. The bar has it made with reassuringly few ingredients: cashews, dates, chocolate chips, and sea salt.

Weight: 40g

Protein: 15g

Calories: 150

Sugar: 1g

Carbs: 15g

Fats: 5g

Review: First warning, if you don't like cinnamon, don't opt for this flavor, as it's overwhelming. Second warning, if you're doing a marathon or anything more vigorous than a brisk walk, this may not be the energy-boosting bar you're after, and that's simply based on its weight.

This flimsy bar feels very underwhelming. It's more like a Rice Krispies Treat than a weighty protein bar. However, it does have a good protein content and is low in calories and sugar. Overall, the taste and weight of it is too off-putting to make it a winner.

Weight: 85g

Protein: 10g

Calories: 390

Sugar: 21g

Carbs: 43g

Fats: 22g

Review: This bar was the most expensive snack in the running, but it didn't live up to the price in its protein content, despite being denser in weight.

On taste alone, it was one of our favorites, plus you can see the ingredients, such as flax seeds, almonds, and peanuts in the bar, so it does feel more natural. But with such high sugar content, it's hard to justify.

Weight: 49g

Protein: 11g

Calories: 200

Sugar: 12g

Carbs: 24g

Fats: 9g

Review: This bar was the closest thing so far to Reese's Pieces, but with a less overpowering taste of peanut. I'd go so far as to say, it's actually better than Reese's.

It prides itself on having "real plant-based food ingredients," which is stamped on the front in garish green letters. The protein in the bar comes from plant-based proteins.

Weight: 65g

Protein: 10g

Calories: 270

Sugar: 13g

Carbs: 34g

Fats: 12g

Review: This bar is about as easy to tear as rubber, which is an instant turn-off. However, it does taste good and is made with natural and vegan ingredients.

The sugar content is pretty high, but it doesn't taste unpleasantly sweet. The sugar is derived from brown rice syrup, which sounds healthy but is no better than any other refined sugar.

Weight: 52g

Protein: 12g

Calories: 220

Sugar: 12g

Carbs: 22g

Fats: 10g

Review: RXBAR was our overall winner. While it was one of the more expensive bars, its ingredients and taste made it a clear leader.

This brand markets itself as having no added flavors and "No B.S." In this chocolate-chip bar, there are three egg whites, six almonds, four cashews, and two dates, and a few chocolate drops. Everything comes from natural ingredients.

Don't be put off by its Italian leather-like finish — it does taste good, and the sugar content is reasonable.