In this article
- How we chose and compared the bars
- High fiber protein bars on one chart
- The nine bars, reviewed
- Which added fibers the FDA actually counts
- Snack bars fiber compared with whole food snacks
- Energy bars, added fiber and your gut
- How to choose protein bars with fiber that suit you
- Why bar labels may keep shifting
- Protein bar and fiber FAQ
- Sources
Seventeen grams. That’s the fiber listed for one Quest Cookies & Cream bar in its USDA record, more than a cup of raspberries and a medium pear deliver together.
Numbers like that put protein bars with fiber in a category of their own, but the ingredient list tells a more complicated story. Almost all of that fiber is added during manufacturing, and not every added fiber counts the same way under current FDA rules.
How we chose and compared the bars
Every figure below comes from the nutrition label each maker submitted to USDA FoodData Central. We picked nine well known bars across three styles: high fiber protein bars, nut or date based bars, and low sugar whey bars.
For each one we recorded calories, protein, fiber and sugars per bar, then read the ingredient list to see where the fiber comes from. The FDA’s Daily Value of 28 grams sets the % DV column.
Some records go back to 2017 or 2018, and bar recipes change often. Use the numbers to compare styles, then confirm the details on the wrapper in your hand.
High fiber protein bars on one chart
| Bar (flavor) | Calories | Protein | Fiber (% DV) | Total sugars | Main fiber source |
|---|---|---|---|---|---|
| Quest (Cookies & Cream), 60 g | 180 | 21 g | 17 g (61%) | 1 g | Isomalto-oligosaccharides |
| Atkins Lift (Choc Chip Cookie Dough), 60 g | 200 | 21 g | 16 g (57%) | 3 g | Soluble corn fiber |
| Pure Protein (Cookies & Cream), 60 g | 210 | 20 g | 15 g (54%) | 2 g | IMO, soluble corn fiber |
| Fiber One Protein (Peanut Butter), 33 g | 130 | 7 g | 8 g (29%) | 2 g | Chicory root extract |
| KIND Protein (Double Dark Chocolate Nut), 50 g | 250 | 12 g | 5 g (18%) | 8 g | Peanuts, almonds |
| RXBAR (Peanut Butter Chocolate), 52 g | 210 | 12 g | 4 g (14%) | 13 g | Dates, peanuts |
| Larabar Protein (Choc Peanut Butter Cup), 52 g | 230 | 11 g | 4 g (14%) | 18 g | Dates, peanuts |
| Barebells (Salty Peanut), 55 g | 200 | 20 g | 3 g (11%) | 1 g | Polydextrose |
| ONE (Birthday Cake), 60 g | 220 | 20 g | 3 g (11%) | 1 g | Polydextrose, dextrin |
The split is stark. The top three bars list 15 to 17 grams of fiber with about 20 grams of protein, while the whole food bars sit at 4 or 5 grams and the low sugar whey bars at 3.
Per 100 calories, Quest leads at about 9.4 grams of fiber and Atkins Lift follows at 8. RXBAR, Larabar, Barebells and ONE all land under 2.
The nine bars, reviewed
1. Quest Protein Bar
Key specs: 180 calories, 21 g protein, 17 g fiber and 1 g sugar per 60 g bar. The protein comes from whey and milk protein isolates.
Best for: a high protein snack with the most fiber per calorie on this list.
Drawbacks: the ingredient list in this 2017 record names isomalto-oligosaccharides (IMO) as its prebiotic fiber, and IMO isn’t on the FDA’s list of recognized added fibers. It also contains erythritol, a sugar alcohol. Check the current wrapper, since the fiber line may read differently today.
2. Atkins Lift Protein Bar
Key specs: 200 calories, 21 g protein, 16 g fiber and 3 g sugar per 60 g bar. Soluble corn fiber is the second ingredient after the whey blend.
Best for: people who want a fiber number near Quest’s with no IMO in the ingredient list.
Drawbacks: nearly all the fiber is one isolated ingredient, so you miss the mix of fibers whole foods provide.
3. Pure Protein Bar
Key specs: 210 calories, 20 g protein, 15 g fiber and 2 g sugar per 60 g bar. The fiber comes from IMO plus soluble corn fiber, with erythritol in the coating.
Best for: a sweeter, candy bar style protein snack with double digit fiber on the label.
Drawbacks: like Quest, this 2018 record lists IMO among its fiber ingredients, so the current label may show a different number.
4. Fiber One Protein Chewy Bar
Key specs: 130 calories, 7 g protein, 8 g fiber, 2 g sugar and 0 g added sugar in a 33 g bar. Chicory root extract, a source of the fiber inulin, is the first ingredient.
Best for: a small, lower calorie snack where fiber matters more than protein.
Drawbacks: 7 grams of protein is modest, and the bar also uses erythritol.
5. KIND Protein Bar
Key specs: 250 calories, 12 g protein, 5 g fiber and 8 g sugar (6 g added) per 50 g bar. Peanuts and almonds are the first two ingredients.
Best for: a whole nut bar where the fiber comes from the nuts themselves.
Drawbacks: the highest calorie bar here, with glucose syrup third on the ingredient list.
6. RXBAR
Key specs: 210 calories, 12 g protein, 4 g fiber, 13 g sugar and 0 g added sugar per 52 g bar. Ingredients start with dates, peanuts and egg whites.
Best for: a short, recognizable ingredient list with no added sugar.
Drawbacks: 13 grams of sugar from dates, and only 4 grams of fiber.
7. Larabar Protein
Key specs: 230 calories, 11 g protein, 4 g fiber and 18 g total sugar per 52 g bar. It’s built on dates, peanuts and pea protein.
Best for: a plant based option that skips whey and egg.
Drawbacks: the most sugar on the list, and fiber that stays in single digits.
8. Barebells Protein Bar
Key specs: 200 calories, 20 g protein, 3 g fiber and 1 g sugar per 55 g bar. The protein blend includes caseinate, whey and collagen.
Best for: a high protein, low sugar bar with a dessert style texture.
Drawbacks: fiber is low, and the bar uses maltitol, a sugar alcohol, as a sweetener.
9. ONE Protein Bar
Key specs: 220 calories, 20 g protein, 3 g fiber, 1 g sugar and 0 g added sugar per 60 g bar. IMO is the second ingredient, with polydextrose and dextrin further down.
Best for: 20 grams of protein with almost no sugar.
Drawbacks: despite IMO near the top of the list, this 2022 record shows just 3 grams of fiber. That’s consistent with IMO not counting as fiber under the current definition.
Trying to decide between these bars, fiber powders and other options? Our comparison charts set out popular picks so you can weigh fiber, protein and sugar together.
Which added fibers the FDA actually counts
Under the FDA’s definition, dietary fiber on a label includes fiber that’s naturally intrinsic and intact in plants, plus isolated or synthetic fibers the agency has found to have a physiological benefit.
Seven made the first list in 2016, including psyllium, cellulose, guar gum and pectin. The FDA has since said it intends to add others, among them inulin, polydextrose and resistant maltodextrin, while it finishes rulemaking.
IMO isn’t on either list. Large manufacturers had to follow the new definition by January 1, 2020, which may explain why older bar records sometimes show more fiber than newer bars built on similar ingredients.
Soluble corn fiber, used in Atkins Lift and Pure Protein, isn’t named on the FDA page by that name. Resistant maltodextrin is, and the agency’s own list is still waiting on a final rule.
Snack bars fiber compared with whole food snacks
Bars are convenient, but whole foods compete well on fiber. These values come from the Dietary Guidelines for Americans fiber list.
| Snack | Fiber | Calories |
|---|---|---|
| Quest bar (2017 record) | 17 g | 180 |
| Raspberries, 1 cup | 8.0 g | 64 |
| Fiber One Protein bar | 8 g | 130 |
| Pear, medium | 5.5 g | 103 |
| Pumpkin seeds, 1 oz | 5.2 g | 126 |
| Almonds, 1 oz | 3.5 g | 164 |
| RXBAR | 4 g | 210 |
A pear with an ounce of pumpkin seeds comes to 10.7 grams of fiber for about 229 calories, which beats every nut and date bar here. You also get fiber that’s intact in the food, the kind the FDA counts without any debate.
If you’re building a target around bars and whole foods, our fiber calculator can show you how far each choice moves your daily total.
Energy bars, added fiber and your gut
Jumping from a low fiber day to a 17 gram bar is a big change. Harvard’s Nutrition Source advises raising fiber gradually and drinking more fluids, since a sudden increase can cause bloating and cramping.
A sensible approach is to start with half a high fiber bar, or a lower fiber one like Fiber One Protein, and see how you feel before moving up.
If you’d like a gradual plan for adding fiber without the discomfort, our gut health guides cover it in detail.
How to choose protein bars with fiber that suit you
Start with what the bar is replacing, then work through a few quick checks:
- If you want the most fiber per calorie: Atkins Lift, Quest or Pure Protein, after confirming the fiber line on today’s wrapper.
- If you want fiber from whole foods: KIND Protein, RXBAR or Larabar, and pair them with fruit to make up the difference.
- If you want small and light: Fiber One Protein at 130 calories and 8 grams.
- If protein is the priority: Barebells or ONE give 20 grams but little fiber, so add a pear or a cup of berries.
- If you avoid sugar alcohols: read the ingredients for erythritol or maltitol, which appear in several of these bars.
A label reading for fiber of 20% DV, or 5.6 grams, meets the FDA’s bar for a high source. Five of these nine bars fall short of that line.
Why bar labels may keep shifting
The FDA list of added fibers is still a work in progress. The agency added cross linked RS4 in 2019, glucomannan in 2020 and acacia gum in 2021 to the fibers it intends to recognize, and it hasn’t finished the rulemaking that would make those additions final.
As that process moves along and makers reformulate, the fiber line on the same bar can change from one box to the next. That’s the strongest reason to compare bars by their current labels, and to lean on whole foods when you want fiber you can count on.
Protein bar and fiber FAQ
Which protein bar has the most fiber?
On their USDA records, Quest lists 17 grams and Atkins Lift lists 16 grams per 60 gram bar. Quest’s older record lists isomalto-oligosaccharides as its fiber source, so check the current wrapper.
Is the fiber in protein bars real fiber?
Partly. The FDA counts some added fibers, such as inulin, polydextrose and resistant maltodextrin, but isomalto-oligosaccharides aren’t on its list.
Are high fiber protein bars good for you?
They can fill a gap, with 15 to 17 grams of fiber and about 20 grams of protein in the top bars. Whole foods still bring fiber that’s naturally intact in the plant.
How much fiber should a protein bar have?
At least 5.6 grams, or 20% DV, to count as a high source under FDA guidance. Only three of the nine bars here clear 10 grams.
Do RXBARs have fiber?
Yes, about 4 grams per 52 gram bar, mostly from dates and peanuts. That’s 14% DV, below the FDA’s high fiber line.
Can protein bars with fiber cause gas?
They can if your fiber jumps quickly. Harvard recommends increasing fiber gradually and drinking more fluids to limit bloating and cramping.
What is chicory root in a protein bar?
It’s a source of inulin, an added fiber the FDA intends to count. Fiber One Protein bars list chicory root extract as the first ingredient.
Sources
- U.S. Department of Agriculture, Agricultural Research Service. “Branded Foods: Quest Cookies & Cream (1903553), Atkins Lift Chocolate Chip Cookie Dough (1907209), Pure Protein Cookies & Cream (1930690), Fiber One Protein Peanut Butter (2517390), KIND Protein Double Dark Chocolate Nut (1949769), RXBAR Peanut Butter Chocolate (2670034), Larabar Chocolate Peanut Butter Cup Protein (2233947), Barebells Salty Peanut (2593341), ONE Birthday Cake (2666692).” FoodData Central. 2017 to 2023. fdc.nal.usda.gov
- U.S. Food and Drug Administration. “Questions and Answers on Dietary Fiber.” 2024. www.fda.gov
- U.S. Food and Drug Administration. “Daily Value on the Nutrition and Supplement Facts Labels.” 2024. www.fda.gov
- Harvard T.H. Chan School of Public Health. “Fiber.” The Nutrition Source. 2022. nutritionsource.hsph.harvard.edu
- U.S. Department of Agriculture and U.S. Department of Health and Human Services. “Food Sources of Dietary Fiber.” Dietary Guidelines for Americans, 2020 to 2025. dietaryguidelines.gov
