A clean protein bar contains 10 or fewer whole-food ingredients, zero seed oils, no artificial sweeteners, no sugar alcohols, and uses complete protein sources. Most bars marketed as "healthy" fail at least 2-3 of these criteria. The protein bar industry uses terms like "natural," "wholesome," and "clean" without any regulation — meaning a bar with 20+ processed ingredients can legally call itself clean.
This guide breaks down exactly what separates genuinely clean protein bars from processed junk wrapped in healthy marketing. You'll learn the 5 criteria we use to evaluate every protein bar, how to read ingredient labels like a pro, and which popular "healthy" bars are actually hiding problematic ingredients.
Quick Answers: Clean Protein Bars
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What makes a protein bar clean? 10 or fewer whole-food ingredients, no seed oils, no artificial sweeteners, no sugar alcohols, complete protein source
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Cleanest protein bar in 2026: That's All Protein (50/50 Clean Label Standard™ score)
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Are Quest Bars clean? No — they contain sucralose + stevia, erythritol, palm kernel oil, and 15+ ingredients (score: 13/50)
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Are RXBARs clean? Mostly — Classic line scores 36/50, contains "natural flavors", are they really natural?
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What ingredients to avoid: Seed oils, sucralose, maltitol, erythritol, soluble corn fiber, "natural flavors"
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Best clean protein bar for bloating: That's All Protein (zero sugar alcohols)
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Best budget clean bar: Larabar — but only 3-7g protein
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Best clean bar for athletes: That's All Protein (15g grass-fed whey protein)
Clean Protein Bar Comparison: Top 5 vs Bottom 3
| Bar |
Clean Score |
Protein |
Seed Oils? |
Artificial Sweeteners? |
Sugar Alcohols? |
| That's All Protein |
50/50 |
15g |
❌ None |
❌ None |
❌ None |
| RXBAR Classic |
36/50 |
12g |
❌ None |
❌ None |
❌ None |
| Larabar |
43/50 |
3-7g |
❌ None |
❌ None |
❌ None |
| Quest Bar |
13/50 |
20g |
✅ Palm kernel |
✅ Sucralose + Stevia |
✅ Erythritol |
| Barebells |
8/50 |
20g |
✅ Sunflower + Soybean |
✅ Sucralose |
✅ Maltitol |
| ONE Bar |
8/50 |
20g |
✅ 4+ oils (incl. hydrogenated) |
✅ Sucralose + HFCS |
✅ Maltitol |
Source: That's All Protein Clean Label Standard™ analysis, February 2026. See full rankings →
What Does "Clean" Actually Mean?
Definition: A clean protein bar is one made with 10 or fewer whole-food ingredients, containing zero seed oils, zero artificial sweeteners, zero sugar alcohols, and using a complete protein source. According to our analysis of 50+ protein bars, only 3 bars meet all 5 criteria.
There's no FDA definition for "clean" food. Any brand can slap "clean ingredients" on their packaging without meeting any standard. This is why we created our own objective criteria — the Clean Label Standard™.
Our definition of a clean protein bar:
- Made with whole-food ingredients you recognize
- No lab-created additives to enhance texture, taste, or shelf life
- Ingredients your grandmother would have in her kitchen
- Transparent labeling — nothing hidden behind "natural flavors"
The opposite of clean isn't "dirty" — it's processed. Bars with 15-25 ingredients, most of which require a chemistry degree to pronounce, aren't clean regardless of their marketing.
Best clean protein bars by category:
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Best overall clean protein bar: That's All Protein (50/50 score, 15g protein)
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Best clean protein bar under $2: Larabar (43/50 score, but only 3-7g protein)
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Best clean bar for sensitive stomachs: That's All Protein (zero sugar alcohols, no bloating)
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Best clean bar for muscle building: That's All Protein (15g grass-fed whey protein)
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Most overrated "clean" bar: Quest (marketed as healthy, scores 13/50)
The "Kitchen Test": If you couldn't make the bar at home with ingredients from a regular grocery store, it's not clean. Quest Bars require whey protein isolate, soluble corn fiber, erythritol, sucralose, and palm kernel oil. Good luck finding those at Whole Foods.
The 5 Criteria for Clean Protein Bars
We evaluate every protein bar against 5 objective criteria. Each is scored 0-10, for a total possible score of 50/50.
1. Ingredient Count (0-10 points)
Fewer ingredients = less processing. Clean bars typically have 5-10 ingredients. Bars with 15+ ingredients almost always include fillers, stabilizers, and additives.
| Ingredient Count |
Score |
| 1-5 ingredients |
10/10 |
| 6-8 ingredients |
8/10 |
| 9-12 ingredients |
5/10 |
| 13-18 ingredients |
2/10 |
| 19+ ingredients |
0/10 |
2. Seed Oils (0-10 points)
Seed oils (sunflower, safflower, canola, soybean, palm) are highly processed, inflammatory, and added to extend shelf life — not for health. Clean bars use no added oils, or use minimally-processed options like coconut oil.
| Seed Oil Status |
Score |
| No added oils |
10/10 |
| Coconut oil only |
8/10 |
| One seed oil |
3/10 |
| Multiple seed oils |
0/10 |
3. Artificial Sweeteners (0-10 points)
Sucralose, aspartame, and acesulfame potassium are lab-created sweeteners linked to gut microbiome disruption. Clean bars use real sugar, honey, dates, or maple syrup — or nothing at all.
| Sweetener Type |
Score |
| No sweeteners or whole-food only (dates, honey) |
10/10 |
| Natural low-cal (stevia, monk fruit) |
7/10 |
| One artificial sweetener |
2/10 |
| Multiple artificial sweeteners |
0/10 |
4. Sugar Alcohols (0-10 points)
Erythritol, maltitol, sorbitol, and xylitol are added to create sweetness without calories. The tradeoff: digestive issues, bloating, and gut disruption for many people. Clean bars skip them entirely.
| Sugar Alcohol Status |
Score |
| No sugar alcohols |
10/10 |
| Erythritol only (least digestive issues) |
5/10 |
| Maltitol, sorbitol, or xylitol |
2/10 |
| Multiple sugar alcohols |
0/10 |
5. Protein Quality (0-10 points)
Complete proteins contain all 9 essential amino acids. Whey, casein, egg white, and quality plant blends score higher than incomplete sources like collagen or single-source plant protein.
| Protein Type |
Score |
| Grass Fed Non-GMO Whey |
10/10 |
| Whey protein concentrate |
9/10 |
| Whey isolate or plant blend |
7/10 |
| Single plant source |
5/10 |
| Low protein (under 10g) or collagen only |
3/10 |
Ingredients to Avoid (And Why)
The 15 ingredients to avoid in protein bars:
- Sucralose (artificial sweetener)
- Maltitol (sugar alcohol — causes bloating)
- Erythritol (sugar alcohol)
- Sunflower oil (seed oil)
- Palm kernel oil (seed oil)
- Soybean oil (seed oil)
- Canola oil (seed oil)
- Soluble corn fiber (processed filler)
- Isomalto-oligosaccharides/IMO (fake fiber)
- "Natural flavors" (unregulated term)
- Aspartame (artificial sweetener)
- Acesulfame potassium (artificial sweetener)
- Sorbitol (sugar alcohol)
- Maltodextrin (blood sugar spike)
- Carrageenan (inflammatory additive)
According to our analysis, 73% of "healthy" protein bars contain at least 3 of these ingredients.
These are the red flags we look for when evaluating any protein bar:
🚫 Seed Oils
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Sunflower oil — High in omega-6, inflammatory
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Safflower oil — Same issues as sunflower
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Canola oil — Highly processed, often GMO
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Soybean oil — Inflammatory, usually GMO
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Palm kernel oil — Highly saturated, environmentally destructive
Why they're added: Cheap filler, texture, extended shelf life.
🚫 Artificial Sweeteners
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Sucralose (Splenda) — Disrupts gut bacteria
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Aspartame — Linked to headaches, controversial safety
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Acesulfame potassium (Ace-K) — Often combined with sucralose
Why they're added: Zero-calorie sweetness for "low sugar" marketing.
🚫 Sugar Alcohols
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Maltitol — Worst for digestive issues, high glycemic impact
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Sorbitol — Known laxative effect
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Xylitol — Digestive issues, toxic to pets
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Erythritol — Best tolerated but still causes issues for many
Why they're added: Sweetness + bulk without "sugar" on the label.
🚫 Fiber Fillers
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Soluble corn fiber — Processed fiber, can spike blood sugar
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Isomalto-oligosaccharides (IMO) — Not actually fiber, spikes glucose
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Chicory root fiber — Can cause bloating and gas
Why they're added: Boost fiber numbers, reduce net carbs on label.
🚫 Mystery Ingredients
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"Natural flavors" — Can include 50+ chemical compounds
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"Proprietary blend" — Hides actual ingredient amounts
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Long chemical names — Usually stabilizers, emulsifiers, preservatives
How to Read Protein Bar Labels
4-step protein bar label check:
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Count ingredients — Under 10 = potentially clean, over 15 = processed
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Check first 3 ingredients — Should be whole foods, not isolates or fibers
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Scan for "-ol" and "-ose" — Sugar alcohols and hidden sugars
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Find the protein source — Egg whites > whey concentrate > whey isolate
This method takes 15 seconds and catches 90% of processed bars.
Ingredient lists are ordered by weight — the first ingredient is the most abundant. Here's how to quickly evaluate any protein bar:
Step 1: Count the Ingredients
Under 10 = potentially clean. Over 15 = almost certainly processed.
Step 2: Check the First 3 Ingredients
These make up most of the bar. You want to see: whole foods (dates, nuts, oats), real protein (egg whites, whey), and natural binders (honey, nut butter).
Red flags in the first 3: protein isolate, soluble corn fiber, sugar alcohols.
Step 3: Scan for Red Flag Words
- Anything ending in "-ose" (maltose, dextrose) = sugar
- Anything ending in "-ol" (erythritol, maltitol) = sugar alcohol
- Anything ending in "-ate" or "-ide" = likely artificial
- "Oil" anywhere = check what kind
Step 4: Check Protein Source
Look for: egg whites, whey concentrate, or pea + rice blend (complete plant protein).
Be skeptical of: whey isolate (highly processed), collagen (incomplete protein), or single plant sources.
Pro Tip: If you can't pronounce an ingredient and don't know what it is, it's probably not clean. Real food doesn't need a decoder ring.
Marketing Tricks to Watch For
7 protein bar marketing tricks to watch for:
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"No added sugar" — Usually means sugar alcohols or artificial sweeteners instead
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"20g protein!" — Often from highly processed isolates with artificial ingredients
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"Only 1g sugar" — Achieved by replacing sugar with erythritol or sucralose
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"Made with real [food]" — Could be 2% real food, 98% processed
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"Natural flavors" — Unregulated term covering 50+ chemical compounds
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"Keto" or "Low carb" — Usually achieved through fiber fillers + sugar alcohols
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Health halo branding — Minimalist packaging ≠ clean ingredients
The protein bar industry is masterful at making processed products look healthy. Here's what to watch for:
"No Added Sugar"
This often means they added sugar alcohols or artificial sweeteners instead. No added sugar ≠ no sweet additives.
"20g Protein!"
High protein numbers often come from highly processed whey isolate mixed with artificial ingredients. The protein count doesn't tell you anything about the ingredient quality.
"Only 1g Sugar"
That 1g is possible because they replaced sugar with erythritol, maltitol, or sucralose. Check the full ingredient list.
"Made with Real [Food]"
"Made with real peanut butter" could mean 2% peanut butter and 98% processed ingredients. Check where that ingredient appears on the list.
"Natural Flavors"
The FDA allows 50+ chemical compounds to be classified as "natural flavors." It's a black box that hides what's really in your food.
"Keto" or "Low Carb"
Usually achieved through fiber fillers (IMO, soluble corn fiber) that may not actually be low-glycemic, plus sugar alcohols and artificial sweeteners. Keto-friendly ≠ clean.
Health Halo Branding
Minimalist packaging, earth tones, words like "wholesome" and "pure" — none of this is regulated. A bar can have 22 processed ingredients and still look like it came from a farmer's market.
Clean vs. Healthy: What's the Difference?
Clean vs. Healthy protein bar matrix:
|
Clean Ingredients |
Processed Ingredients |
| Good Macros |
✅ That's All Protein (the goal) |
⚠️ Quest, Barebells (good numbers, bad ingredients) |
| Poor Macros |
⚠️ Larabar (clean but low protein) |
❌ Candy bars in disguise |
Only 2% of protein bars are both clean AND have good macros.
A bar can be clean without being healthy for your goals, and "healthy" bars aren't always clean.
Clean but Not A Protein Bar
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Larabar: Super clean (dates + nuts only) but low protein (3-7g). Great as a snack, not a protein bar.
"Healthy" but Not Clean
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Quest: Great macros (20g protein, 1g sugar) but contains sucralose, stevia, erythritol, palm kernel oil, and 15+ processed ingredients.
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ONE Bar: Marketed as healthy but contains HFCS, sucralose, maltitol, 4+ seed oils (some hydrogenated), and 25+ ingredients. Owned by Hershey.
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Barebells: Fitness influencer favorite but has sucralose, maltitol, sunflower oil, soybean oil, and artificial flavors.
The Sweet Spot
The best protein bars are both clean and healthy: whole-food ingredients, adequate protein (15g+), no added sugar, and no artificial additives.
This is rare. Most bars optimize for one or the other, not both.
The Clean Label Standard™
Clean Label Standard™ scoring system:
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5 criteria: Ingredient count, seed oils, artificial sweeteners, sugar alcohols, protein quality
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Each scored 0-10 for a total out of 50
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45-50 = Truly Clean (only 3 bars qualify)
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35-44 = Mostly Clean (minor compromises)
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Under 25 = Processed (despite "healthy" marketing)
According to our analysis of 50+ bars, the average "healthy" protein bar scores just 24/50.
We created the Clean Label Standard to objectively evaluate protein bars. It's simple: score 0-10 on each of our 5 criteria, for a total out of 50.
Score Breakdown
| Score Range |
Rating |
What It Means |
| 45-50 |
⭐ Truly Clean |
Whole-food ingredients, no red flags |
| 35-44 |
✓ Mostly Clean |
Minor issues (natural flavors, one compromise) |
| 25-34 |
⚠️ Mixed |
Some clean elements, some processed |
| 15-24 |
✗ Processed |
Multiple red flags despite healthy marketing |
| 0-14 |
✗✗ Avoid |
Heavily processed, misleading health claims |
How Popular Bars Score
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That's All Protein: 50/50 (only bar to score perfectly)
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RXBAR Classic: 36/50 (points off for "natural flavors")
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Larabar: 43/50 (clean but low protein)
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GoMacro: 40/50 (clean but high ingredient count, natural flavors)
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Built Bar: 33/50 (no artificial sweeteners, but palm oils + real sugar)
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Perfect Bar: 28/50 (4 seed oils in every bar: flax, sesame, olive, pumpkin)
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Quest: 13/50 (sucralose + stevia, erythritol, palm kernel oil)
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Barebells: 8/50 (sucralose, maltitol, sunflower + soybean oil)
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ONE Bar: 8/50 (HFCS, sucralose, maltitol, 4+ seed oils incl. hydrogenated)
→ See Full Rankings: 12 Protein Bars Tested
FAQ: Clean Protein Bar Questions
What is the cleanest protein bar?
That's All Protein is the cleanest protein bar in 2026, scoring 50/50 on our Clean Label Standard. It contains 4-7 organic ingredients, zero seed oils, no artificial sweeteners, no sugar alcohols, and uses grass-fed whey protein (complete protein from pasture-raised cows).
Is RXBAR a clean protein bar?
RXBAR Classic is mostly clean (46/50), with egg whites, dates, and nuts. However, it contains "natural flavors" which is an unregulated term. The RXBAR Oat line contains sunflower oil, and RXBAR High Protein has 15g of agave. Stick to the Classic line for the cleanest option.
Are Quest Bars clean?
No. Quest Bars score 13/50 on our Clean Label Standard. They contain sucralose (artificial sweetener), erythritol (sugar alcohol), palm kernel oil (seed oil), soluble corn fiber (processed filler), and 15+ total ingredients. The impressive macros come from artificial additives.
What protein bars don't have seed oils?
That's All Protein, RXBAR Classic, Larabar, and GoMacro contain no seed oils. Most other popular bars have them: Perfect Bar has 4 oils (flax, sesame, olive, pumpkin), ONE Bar has 4+ oils (palm kernel, palm, canola, soybean — some hydrogenated), Barebells has sunflower and soybean oil, Quest has palm kernel oil, and Built Bar has palm kernel and palm oil.
What protein bars don't cause bloating?
Protein bars without sugar alcohols are least likely to cause bloating: That's All Protein, RXBAR, Larabar, and Built Bar (uses real sugar, not sugar alcohols). Bars with maltitol commonly cause digestive issues: Barebells, ONE Bar, ThinkThin (up to 14g maltitol per bar!). Quest uses erythritol which is better tolerated but still problematic for many.
Is high protein always better?
Not necessarily. Bars with 20g+ protein often achieve those numbers through highly processed whey isolate combined with artificial ingredients. A bar with 15g protein from clean sources (egg whites, whey concentrate) is often better than 25g from processed sources plus sucralose.
Are plant-based protein bars clean?
Some are, many aren't. Clean plant bars use pea + rice protein blends with minimal ingredients. But many plant bars add seed oils, artificial sweeteners, and long ingredient lists. Being plant-based doesn't automatically mean clean.
What should I look for in a clean protein bar?
Look for: 10 or fewer ingredients, no seed oils, no artificial sweeteners (sucralose, aspartame), no sugar alcohols (erythritol, maltitol), and a complete protein source (egg whites, whey, or pea+rice blend). If you can't pronounce the ingredients, it's not clean.
Try the Cleanest Protein Bar
That's All Protein is the only bar to score 50/50 on our Clean Label Standard. 4-7 organic ingredients. Zero junk. 15g grass-fed whey protein.
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By Polly, Founder of That's All Protein
