Are Fiber One Bars Healthy For You? Dietitian Review

Most of us need a quick and easy way to get more fiber, but are Fiber One bars healthy? Read this Dietitian review to find out!

Fiber One bars have been around since 2007, making them one of the OG fiber-packed snacks. With a sweet, chewy texture and a hefty dose of fiber in every bar, it’s no surprise they’ve stayed popular for nearly two decades.

If you didn’t know, 95% of Americans do not get the recommended amount of fiber. Fiber helps you to feel full, slows digestion of carbohydrates, lowers blood sugar and blood cholesterol levels, helps prevent constipation, reduces the risk of colon cancer (and other cancers), and helps feed a healthy gut microbiome. 

Because fiber plays a large role in so many areas of health and how we feel, getting at least the recommended daily amount is essential.

Fruits, vegetables, whole grains, and other plant foods are all great ways to boost your intake, but many packaged convenience foods have added fiber to help bridge the gap. This is where Fiber One bars shine. 

But are Fiber One bars actually a healthy choice? I’m Kelsey, a registered dietitian and a busy mom. I know how important it is to have quick, grab-and-go snacks that don’t just taste good but also offer real nutrition.

So, I took a deep dive into the ingredients, nutrition facts, benefits, and potential downsides to help you decide if these high fiber bars deserve a spot in your snack rotation.

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What Are Fiber One Bars?

General Mills makes Fiber One bars, which include the OG chewy bars and several other snackable, high fiber treats. They’re high-fiber, low-calorie snacks that give you a fiber boost while satisfying a sweet tooth. 

The Fiber One bar lineup includes:

• Chewy Bars: Soft and chewy oat-based granola bars with flavors like oats and chocolate, chocolate peanut butter, chocolate, and chocolate caramel and pretzel. 
• Protein Bars: Higher in protein with 10 grams each, with flavors like strawberries and cream, chocolate chip, peanut butter chocolate, and chocolate fudge. 
• Sweet Treat Bars: Fiber filled “desserts” like brownies and strawberry cheesecake bars. These bars are higher in calories than the other bars, but still high in fiber. 
• Soft-Baked Bars: Low calorie sweet snack bars that have a texture almost like dense cake. They come in flavors like birthday cake, cinnamon coffee cake, chocolate chip cookie, and chocolate fudge. 

Fiber One Bar Nutrition: What’s Inside?

Each Fiber One bar variety has a slightly different nutrition profile. All bars except for the sweet treat bars, the oats and chocolate soft and chew bars, and the caramel nut protein chewy bars have under 100 calories. 

All Fiber One bars have between 5 and 9 grams of fiber (19% to 32% of the recommended daily value). 

Most are also very low in protein, except for the protein bars, which have 10 grams of protein each, and 6 grams of protein in the soft and chewy caramel nut protein bar. 

This is what you’ll find in one oats and chocolate soft and chewy bar:  

• Calories: 150
• Protein: 2 grams
• Carbohydrates: 29 grams
• Fiber: 9 grams
• Added Sugar: 8 grams
• Fat: 4 grams

Fiber One Bar Ingredients: What’s Inside?

The exact ingredients vary by flavor, but many of the base ingredients stay the same. Here is a breakdown of the ingredients in the Oats and Chocolate Soft and Chewy Bar. 

Fiber sources

Fiber One bars include chicory root extract, whole grain oats, whole grain barley flakes, and sugar cane fiber to pack a high amount of fiber into a little bar. Chicory root fiber likely makes up the bulk of fiber in these bars. As a source of inulin, it’s high in prebiotic fiber, but is a high FODMAP food and may cause digestive discomfort in some people. 

Semisweet chocolate and cocoa powder

Used to add flavor and texture to the bars. 

Added sugars

The sweet taste of Fiber One bars comes from added sugars like corn syrup, sugar, barley malt extract, and fructose. Corn syrup, barley malt extract, and sugar are broken down mostly into glucose (and small amounts of fructose) to be used by your cells for energy.

Fructose may have a slightly smaller immediate effect on your blood sugar, but needs to be processed by the liver before it can be used for energy, which can lead to negative effects if high amounts of added fructose are eaten over time. 

NOTE: Lower-calorie Fiber One bars, like protein bars, use sugar and alcohols like isomalt, which can cause digestive upset in some people. 

Canola oil and palm kernel oil

Canola oil is a vegetable oil that’s rich in unsaturated fatty acids while palm kernel oil is a plant-based source of saturated fat. 

Canola oil has a bad reputation as an inflammatory oil because of the manufacturing process and omega-6 to omega-3 ratio, but much of the research that points to it as an inflammatory oil has been found in animal studies receiving excessively high doses of canola oil. 

Palm oil is half saturated fat and half unsaturated fats, mostly monounsaturated fatty acids. A large review of 51 studies found that the positive effects of palm oil on heart health depend on what it’s replacing in the diet.

Better outcomes were found when it replaced trans fats, while diets high in monounsaturated and polyunsaturated fats had more favorable heart health outcomes. 

Maltodextrin

Maltodextrin is a highly processed carbohydrate that’s often used in packaged foods like Fiber One bars for texture and to improve shelf life, but also acts as an added sugar. 

Tricalcium phosphate

Adds calcium to these bars, making each one a good source of calcium with 10% of your DV in each bar. It may also act as an anti-caking agent helping to improve the texture.  

Other ingredients

These bars use cocoa powder and semisweet chocolate for flavor, rice flour, soy lecithin, cellulose gum, and vegetable glycerin for texture, baking soda and milk powder, natural flavor, and vitamin E, which acts as a preservative. 

The Benefits and Drawbacks of Fiber One Bars

The Pros

• Good source of fiber: Many Fiber One bars contain 5 grams or more per serving, helping you meet your daily fiber goals.
• Lower in calories: Compared to many granola or protein bars, these are lower in calories, making them a light snack option or even “dessert” after a meal. 
• Dessert-like flavors: If you have a sweet tooth, these bars can be a satisfying alternative to candy bars or cookies, since the added fiber will help slow down the absorption and digestion of the sugar. 
• Convenient: A quick and easy way to add more fiber to your diet without extra prep. A good option for traveling when your fresh food options may be limited. 

The Cons

• High in added sugars or sugar alcohols: Fiber One bars either have added sugars (sometimes up to 18% DV) or use sugar alcohols to keep the calories lower (protein bars, low-cal chewy bars, soft baked bars), which can cause digestive upset in some people. 
• Low in protein: Unless you’re eating a Fiber One Protein Bar, the bars are very low in protein with only 1-3 grams per bar. 
• Processed ingredients: While they provide fiber, they also contain added sugars, vegetable oils, and preservatives. While none of these ingredients are problematic when eaten in small amounts, some people may choose to limit them in their packaged foods. 
• May cause digestive issues: Some people experience bloating or gas due to the high amount of fiber, the type of fiber, and the sugar alcohols used in these bars.

Taste Test: My Review of the Oats & Chocolate Fiber One Bar

To give an honest review, I tried one of Fiber One’s most popular flavors: Oats & Chocolate. Here’s my take:

• Flavor: The chocolate drizzle and chips make it taste more like a dessert than a granola bar, which could be a plus if you’re looking for something sweet. I didn’t love the syrup-y flavor and coating on the bars though. 
• Texture: I like the texture of these bars. They’re light and easy to chew quickly, unlike a lot of protein and fiber bars. 

Would I eat it again? Occasionally. While it’s a decent sweet snack, I prefer bars with more protein and other benefits. Looking at the balance of benefits and enjoyment/flavor… they fell a little short.

Plus, in my experience, too much inulin fiber at once can lead to excess gas, which isn’t always convenient or enjoyable. 

Final Verdict: Are Fiber One Bars Healthy?

Fiber One bars can be a convenient way to increase fiber intake, but they aren’t the most natural or nutrient-dense option.

While they provide a good dose of fiber in a small package, they also contain added sugars, processed fiber sources, and lower amounts of protein and healthy fats compared to other snack bars.

If you enjoy the taste and tolerate the ingredients well, Fiber One bars can be a part of a balanced diet, but should be looked at more as a treat or a fiber boost in a pinch, not a regular replacement for other high fiber foods.

Have you tried Fiber One bars? Let me know your favorite flavor in the comments.