Dr. Becky Maes - Is It Bad For You? Approved by Dr. Becky Maes

Are Fiber One Bars Bad For You?



Short answer

Yes, Fiber One bars are bad for you. Although they contain around nine grams of fiber, they also have up to 10 grams of sugar—plus artificial colors and flavors. There are better ways to get your daily recommended serving of fiber.



Recommended Alternative

Long answer

Dietary fiber is an essential nutrient. Most notably, your body needs it for healthy digestion; it helps prevent or even relieve constipation. But fiber-rich foods provide a lot of other health benefits as well. They help promote a healthy weight and can even reduce your risk of developing heart disease and diabetes.

So where can you find fiber? Most commonly, fiber is naturally abundant in fruits and vegetables. And typically, the darker the veggie, the more fiber it contains—artichokes pack up to 10 grams of fiber per serving, while spinach weighs in around 7. However, dietary fiber is not exclusive to fruits and vegetables; it’s also found in whole grains and legumes.

If you’re looking to get more fiber in your diet, you might consider Fiber One bars. As the name suggests, these products contain a good amount of fiber: approximately 9 grams per 140-calorie bar. That’s about 24 percent of the daily recommended value for men, and 36 percent for women.

But if something seems to be too good to be true, it probably is.

In addition to providing up to 9 grams of dietary fiber, Fiber One bars also contain around 10 grams of sugar per serving. That’s quite a big of sugar for something marketed as a health bar.

Sugar should be avoided whenever possible because it spikes insulin levels, which leads to an energy crash shortly thereafter. And that’s only the short-term. Regular overconsumption of sugar can lead to fat storage, which is the basis for obesity and the slew of health problems that come along with it.

In addition to the high amount of sugar in Fiber One bars, there are many other concerning ingredients, such as high maltose corn syrup, caramel coloring and “natural flavors.” High maltose corn syrup is not as bad for you than high fructose corn syrup—but it does contain fructose which can lead to tooth decay if consumed frequently. Caramel coloring is questionable as well. It’s most commonly used in soda, and some types include 4-methylimidazole (4-MeI), a potential carcinogen. “Natural flavors” is perhaps the most suspicious ingredient. This is an umbrella term which can mean pretty much anything that is "derived" from a natural source. 

Our advice: skip the Fiber One bars. If you need more fiber in your diet, try to get as much of it as possible from fresh fruits and vegetables. You may have to eat more of them—but at least you know what you’re eating.

Possible short-term side effects

  • spikes insulin
  • sugar crash

Possible long-term side effects

  • tooth decay
  • obesity
  • diabetes
  • heart disease
  • cancer (from carcinogenic 4-mei)

Ingredients to be aware of


  • convenience
  • 9 grams of fiber

Healthier alternatives

  • get your fiber from fruits & veggies

Our Wellness Pick (what is this?)

Quest Protein Bar

  • High in protein
  • Low carb
  • Gluten-free
  • Keto-friendly
  • Oatmeal Chocolate Chip flavor
Learn More!

Thank you for your feedback!

View Sources | Written by Rachel Adams
Published on: 12-18-2016
Last updated: 12-15-2023

Thank you for your feedback!

View Sources
Written by Rachel Adams
Published on: 12-18-2016
Last updated: 12-15-2023

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