Which Protein Bar Has the Most Fiber? 19 Bars Ranked, From No Cow's 15g to Built Bar's Under 1g (2026)

All 19 Verified Protein Bars, Ranked by Grams of Fiber

Every figure below comes from each bar’s own dedicated nutrition-facts breakdown already published on this site (linked in the Bar column), sourced from the brand’s official label. We used each bar’s flagship or most-verified flavor; where a brand sells multiple lines with meaningfully different fiber (Perfect Bar Original vs. Protein+Prebiotics, KIND Protein vs. Protein Max), both are included.

* Barebells does not publish a fiber line on its official nutrition-facts panel; the ~3g figure is this site’s own comparison-table estimate, not a confirmed label number — treat it as approximate, unlike every other entry above.

Power Crunch is left off the ranked list entirely because neither its Original nor PRO nutrition panel discloses a fiber value — the label simply omits the line, so we show it as unknown rather than guess at a number.

The 20g-Protein Cluster, Rebuilt Around Fiber

Our companion ranking by grams of protein found thirteen bars tied at exactly 20g of protein. Fiber breaks that tie almost as sharply as calories and sugar do. Atkins Strong (8g), Ghost (7g), and KIND Protein Max (7g) all carry real fiber alongside their 20g of protein. Clif Builder’s and Barebells, tied at the same 20g of protein, land at only about 3g of fiber. Pure Protein sits at the very bottom of that tie at 1g. Meanwhile DAVID Gold, Pure Protein, and Built Bar post some of the best protein-per-calorie numbers on the site (see our protein-to-calorie ratio ranking) but sit at the bottom on fiber, at roughly 1g or less.

Why Fiber Is Worth Tracking Alongside Protein

The FDA’s Daily Value for fiber is 28g, and most people fall well short of it. A protein bar that also delivers meaningful fiber does double duty: fiber slows digestion, which extends satiety past what protein alone provides. No Cow’s 15g of fiber is more than half of a full day’s target in a single bar; Quest and Kirkland’s 12g cover close to half. At the other end, DAVID Gold, Pure Protein, and Built Bar are excellent picks for pure protein-per-calorie efficiency but contribute almost nothing toward a daily fiber target — about 1g or less each.

The Trade-Off: High Fiber Can Mean More Digestive Discomfort

Fiber isn’t a pure upside. Several of the highest-fiber bars above also lean on sugar alcohols: Quest, Kirkland Signature, and Atkins Strong all use erythritol-based sweetener systems, and No Cow’s sweetener blend includes erythritol alongside stevia and monk fruit (per each bar’s own nutrition-facts review on this site). Stacking high fiber with sugar alcohols can compound bloating or GI discomfort for some people, especially when eating more than one bar at a sitting or without much water. If digestive sensitivity is a bigger concern than hitting a fiber target, a lower-fiber bar in this ranking — Built Bar, Pure Protein, or DAVID Gold, all at roughly 1g of fiber or less — is the gentler starting point.

Best Pick by Goal

• Maximum fiber, period: No Cow — 15g of fiber in a 170-calorie, plant-based bar, more than half the daily 28g target in one sitting.
• Best fiber-and-protein balance: Quest or Kirkland Signature — 12g of fiber alongside 21g of protein, the strongest combined total of any bar on this list.
• High fiber without sugar alcohols: Lenny & Larry’s Complete Cookie — 10g of fiber, sweetened with real sugar rather than erythritol or maltitol (though at ~440 calories with real added sugar, it’s a different trade-off; see our full Complete Cookie breakdown).
• Most protein per calorie, least fiber: DAVID Gold — 28g of protein in 150 calories, but only about 1g of fiber; pair it with a fiber-rich side if fullness matters as much as protein.
• Gentlest on digestion: Built Bar, Pure Protein, or DAVID Gold — all at roughly 1g of fiber or less, the safest starting point if high-fiber bars have caused you discomfort before.

Frequently Asked Questions

Which protein bar has the most fiber?

No Cow, at 15g of fiber per ~60g bar (170 calories, 20g protein). Quest and Kirkland Signature tie for second at 12g each.

Do high-protein bars usually have a lot of fiber?

No — the two numbers don’t track together. DAVID Gold has the most protein of any bar on this site (28g) but only about 1g of fiber. Built Bar (17g protein) and Pure Protein (20g protein) come in even lower, at under 1g and 1g of fiber respectively. Fiber and protein are formulated into a bar independently, so a high number on one doesn’t predict a high number on the other.

Why do some bars not list fiber at all?

Power Crunch’s nutrition panel, for both its Original and PRO lines, simply doesn’t include a fiber line item — it isn’t a formulation secret, the label just omits it. We show that as unknown rather than assuming 0g, since an undisclosed fiber value is not the same as a verified zero.

Can too much fiber from protein bars cause digestive issues?

Yes, especially when a high-fiber bar is combined with sugar alcohols like erythritol, which several of the higher-fiber bars on this list use (Quest, Kirkland Signature, Atkins Strong, and No Cow all use erythritol-based sweetener systems per their own nutrition-facts reviews). Eating more than one high-fiber bar at a sitting, or without much water, is the most common trigger for bloating or discomfort.

Is 1g of fiber in a protein bar bad?

Not inherently — it just means the bar isn’t contributing meaningfully toward your daily fiber target. Bars like DAVID Gold, Pure Protein, and Built Bar are built around protein efficiency (high protein, low calories) rather than fiber, which is a legitimate design choice if you get fiber from elsewhere in your diet.

Bottom line: No Cow delivers more fiber than any protein bar we’ve verified — 15g in a single bar, ahead of Quest and Kirkland Signature’s 12g — and the bigger lesson is that fiber and protein don’t move together. Several of the highest-protein bars on this site (DAVID Gold, Pure Protein, Built Bar) carry almost none, while several bars in the crowded 20g-protein tier (Atkins Strong, Ghost, KIND Protein Max) quietly deliver real fiber alongside their protein. Pick No Cow or Quest if fiber and fullness matter as much as protein; pick DAVID Gold if pure protein-per-calorie efficiency is the only filter that matters. Compare every bar side by side in our best protein bars of 2026 guide, see the full protein-gram ranking in which bar has the most protein, or browse the full protein snacks directory.