Quest vs RXBAR Protein Bars
Quest and RXBAR are the classic engineered versus whole food matchup. Quest builds its bar from protein isolates and fiber, sweetened with erythritol and stevia, and lands around 11g of protein per 100 calories with roughly 1g of sugar. RXBAR builds its bar from egg whites, dates and nuts with no added sweeteners at all, which means notably less protein per calorie and much more sugar, all of it from fruit. Which one wins depends entirely on whether you are optimising the label or the ingredient list. Every number below is transcribed from the manufacturer’s nutrition label and verified by hand, then compared across every flavour we have checked.
The numbers, side by side
Values are shown as the range across every flavour we have verified (11 Quest Bar flavours, 8 RXBAR Protein Bar flavours). Winner is decided on the median flavour.
| Per bar | Quest Bar | RXBAR Protein Bar |
|---|---|---|
| Protein per bar | 20–21gWinner | 12g |
| Calories per bar | 170–190 kcalWinner | 180–210 kcal |
| Protein per 100 kcal | 11.1–11.8gWinner | 5.7–6.7g |
| Sugar per bar | 0.5–2gWinner | 14–17g |
| Fiber per bar | 12–15gWinner | 3–6g |
| Fat per bar | 6–9gWinner | 6–9g |
| Bar size | 60g | 52g |
| Sugar alcohols | Erythritol | None |
| Other sweeteners | Sucralose, Stevia | None |
| Protein sources | Milk Protein Isolate, Whey Protein Isolate, Caseinate | Egg White |
Ingredients worth noting
Quest Bar
- Erythritol: A sugar alcohol that is close to zero calorie, does not raise blood glucose, and is better tolerated digestively than most polyols.
- Palm Oil: Palm oil is pressed from the fruit of the oil palm; palm kernel oil comes from the seed inside that same fruit.
RXBAR Protein Bar
- Nothing flagged in any verified flavour.
Where they rank
Quest Bar
- #2 of 6 in Best Protein Bars for GLP-1 Users
- #2 of 6 in Best Protein Bars for Ozempic Users
- #2 of 6 in Best Protein Bars for Mounjaro & Zepbound Users
- #2 of 10 in Protein Bars Without Sugar Alcohols
- #3 of 10 in High Fiber Protein Bars
- #3 of 10 in Low Sugar Protein Bars
- #3 of 10 in Protein Bars Without Maltitol
- #3 of 10 in Protein Bars Without Seed Oils
- #4 of 10 in Best Protein Bars
- #4 of 42 in Highest Protein Bars Per Calorie
RXBAR Protein Bar
- #10 of 10 in Protein Bars Without Artificial Sweeteners
- #28 of 42 in Highest Protein Bars Per Calorie
Frequently asked questions
- Which has more protein per calorie, Quest Bar or RXBAR Protein Bar?
- Quest Bar, with 11.1g of protein per 100 calories against 6.2g for RXBAR Protein Bar (median across all verified flavours).
- Which has more fiber, Quest Bar or RXBAR Protein Bar?
- Quest Bar, with 12–15g of fiber per bar against 3–6g for RXBAR Protein Bar.
- Do Quest Bar and RXBAR Protein Bar contain sugar alcohols?
- Quest Bar: Erythritol. RXBAR Protein Bar: None. This comes from the verbatim ingredient list of every flavour we have verified.
Every Quest Bar flavour we have verified
Birthday Cake20g protein · 180 kcal · 11.1g / 100 kcal
Blueberry Muffin20g protein · 180 kcal · 11.1g / 100 kcal
Chocolate Brownie20g protein · 170 kcal · 11.8g / 100 kcal
Chocolate Chip Cookie Dough21g protein · 190 kcal · 11.1g / 100 kcal
Cookies & Cream21g protein · 190 kcal · 11.1g / 100 kcal
Double Chocolate Chunk20g protein · 170 kcal · 11.8g / 100 kcal
Lemon Cake20g protein · 180 kcal · 11.1g / 100 kcal
Mint Chocolate Chunk20g protein · 180 kcal · 11.1g / 100 kcal
Oatmeal Chocolate Chip20g protein · 180 kcal · 11.1g / 100 kcal
S'mores21g protein · 190 kcal · 11.1g / 100 kcal
White Chocolate Raspberry20g protein · 180 kcal · 11.1g / 100 kcalEvery RXBAR Protein Bar flavour we have verified
Blueberry12g protein · 180 kcal · 6.7g / 100 kcal
Chocolate Sea Salt12g protein · 200 kcal · 6g / 100 kcal
Coconut Chocolate12g protein · 200 kcal · 6g / 100 kcal
Peanut Butter12g protein · 190 kcal · 6.3g / 100 kcal
Peanut Butter Chocolate12g protein · 210 kcal · 5.7g / 100 kcal
Pumpkin Spice12g protein · 210 kcal · 5.7g / 100 kcal
Strawberry12g protein · 190 kcal · 6.3g / 100 kcal
Vanilla Almond12g protein · 190 kcal · 6.3g / 100 kcalAll numbers on this page are transcribed from each manufacturer’s published nutrition label and verified by hand, then compared across every flavour in our database. If you are tracking a daily protein target, the Protein Pal app lets you scan either bar and log it in seconds. See everything from Quest Bar and RXBAR Protein Bar, or browse all rankings and brands.
