Move over, protein? Honestly, probably not. However, TikTok is hungry for another nutrient: Fiber. Single videos about “fiber-maxxing” have racked up tens of thousands—and sometimes over a million—views on the platform. According to influencers, weight loss is one of the primary benefits.
No registered dietitian is disputing that fiber—a nutrient more than 90% of U.S. adults struggle to get—is important for weight loss and overall health.
“Fiber keeps you feeling full longer, which makes it easier to eat less without feeling deprived,” says Dr. Chris Mohr, Ph.D., RD, a fitness and nutrition advisor with BarBend. “It also helps steady blood sugar levels, preventing the energy crashes that lead to overeating or snacking on junk food. In short, it helps you control appetite naturally.”
However, RDs stress that looking at the total package (literally) is vital when choosing foods. Some high-fiber snacks can actually hurt weight loss goals.
“Many times high fiber packaged foods and snacks also contain unhealthy ingredients like processed sugar, fats and preservatives,” explains Lacy Puttuck, MS, RDN, CISSN, CSCS, a registered dietitian with Top Nutrition Coaching. “Reading not only the nutrition facts label is important, but also the ingredients list.”
She says these elements can contribute to weight gain and other health issues. She and three other registered dietitians suggest that people—especially anyone who is trying to lose weight—limit this high-fiber snack. Here’s the what and why.
The No. 1 High-Fiber Snack To Avoid When Trying To Lose Weight, RDs Say
Registered dietitians share that many commercial (and even some homemade) smoothies can make losing weight harder, despite having a “healthy” reputation. “Smoothies can seem healthy, but when they’re packed with fruit juice, syrups or sweetened yogurt, you can end up drinking more calories than you realize,” Dr. Mohr points out.
While calories are vital for maintaining energy and satisfaction, the ones in these kinds of smoothies can do the opposite—sans nutrition.
“Because smoothies are liquid, they don’t keep you full the same way solid foods do,” explains Michelle Routhenstein, MS, RD, CDCES, CDN, a preventive cardiology dietitian and certified diabetes educator at EntirelyNourished.com. “Many sugary smoothies also have a high glycemic load, which can lead to blood sugar spikes and crashes, increasing grazing and cravings.”
Beyond weight gain, Puttuck adds that over-consuming added sugar can lead to:
The American Heart Association recommends that women limit added sugar intake to 100 calories per day (about six teaspoons). For men, the AHA’s guidelines state that it’s best to limit added sugar consumption to 150 calories per day (approximately nine teaspoons).
“Most smoothies that are commercially available with added sugar contain added sugar over that amount,” Puttuck warns.
Related: 7 Weird Ways Your Body Tells You That You Need To Eat Less Sugar
How To Build a High-Fiber Smoothie That Supports Weight Loss
You can still have a high-fiber smoothie snack and lose weight. “With the right ingredients, a homemade smoothie can be a great addition to a daily eating routine,” says Rachel Gargano, MS, RD, CSSD, CBS, the chief registered dietitian at Live it Up. “The goal is to make sure that it not only contains ample fiber, but also protein to promote more satiety—and of course, to avoid the added-sugar trap.”
Here’s what Gargano puts in her blender:
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A base. Gargano reports that a solid liquid foundation is key. Opt for skim, 1% or unsweetened plant milk over 100% fruit juice, which can contribute to weight gain. “Skim or 1% milk can work well, or an unsweetened plant milk,” she says.
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An antioxidant. “Frozen berries help give your smoothie an icy, thick texture, plus they’re less expensive,” Gargano reports. “Most people do well with about ½ cup or less. You may also consider a few chunks of banana.”
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Greens. Here’s where the fiber-maxxing magic happens. “Pack in baby spinach or kale for fiber, volume, and micronutrients,” Gargano says.
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Pack it with protein. Fiber and protein are a total power couple when it comes to feeling satisfied after a snack (helping with any weight loss efforts). Some of Gargano’s favorite protein sources include fat-free Greek yogurt (plain has less added sugar) or a powder. “If choosing a powder, look for one with minimal other ingredients—we’re just looking for the protein here, not a meal replacement powder,” Gargano advises.
Related: Doctors Are Begging People Trying To Lose Weight To Stop Doing This One Thing With Fruit
Other Fiber-Rich Snacks for Weight Loss
High-fiber smoothies packed with added sugar? No. High-fiber smoothies loaded with greens, fruits and protein—sans added sugar? You bet. However, you may prefer solid snacks or want to have a few options. Registered dietitians shared great high-fiber snacks for people trying to lose weight (or maintain a healthy one).
1. Avocado toss
Gargano says this snack contains:
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½ of an avocado, chopped
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2 tablespoons of part-skim ricotta
“Mix them together and season with salt, pepper and your choice of herbs and spices—Tajin works well,” Gargano says.
Gargano reports that this snack will net you 155 calories, 7 grams of fiber and 10 grams of protein.
2. Air-popped popcorn
Routhenstein recommends this snack for Sunday matinees and any day.
“I love air-popped popcorn because it is naturally high in fiber and low in calories,” she says. “You can have a hefty three-cup portion, and you can flavor it to what you are in the mood for. I sometimes will make it sweet with cinnamon, and most times add in a savory blend of garlic powder, oregano and basil for a savory high-volume snack.”
3. Chia pudding
Routhenstein hails chia seed pudding as one of her “go-to high-fiber snacks” and a staple in her meal prep routine.
“By combining chia seeds with milk, banana, nut butter and a touch of cinnamon, it transforms into a creamy, peanut butter banana-flavored treat,” Routhenstein notes. “It’s not only delicious but also packed with fiber, plant-based omega-3s, magnesium and calcium, making it both satisfying and nutrient-dense.”
Related: I Quit Sugar 6 Weeks Ago, and I’m Genuinely Surprised by the Results
What About Fiber Supplements?
Most people struggle to get enough fiber in their diets. Many commercial or packaged high-fiber snacks can contain ingredients like added sugar that don’t help in weight loss efforts—is it safer to stick with supplements? Not really—or at least not ideally, registered dietitians say.
“Fiber supplements can help fill in gaps, but they don’t give you the vitamins, minerals, and phytonutrients that come from whole foods,” Dr. Mohr says. “Foods like fruits, vegetables, beans and whole grains offer a wider range of benefits. Supplements can be a backup plan, but food should be your foundation for both weight loss and long-term health.”
Just make sure those high-fiber snacks and meals containing produce and whole grains aren’t loaded with added sugar.
Up Next:
Sources:
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Closing America’s Fiber Intake Gap. American Journal of Lifestyle Medicine.
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Dr. Chris Mohr, Ph.D., RD, a fitness and nutrition advisor with BarBend
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Lacy Puttuck, MS, RDN, CISSN, CSCS, a registered dietitian with Top Nutrition Coaching
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Michelle Routhenstein, MS, RD, CDCES, CDN, a preventive cardiology dietitian and certified diabetes educator at EntirelyNourished.com
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Added Sugars. American Heart Association.
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Rachel Gargano, MS, RD, CSSD, CBS, the chief registered dietitian at Live it Up
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Consumption of 100% Fruit Juice and Body Weight in Children and Adults. JAMA Pediatrics.
This story was originally reported by Parade on Sep 7, 2025, where it first appeared in the Health & Wellness section. Add Parade as a Preferred Source by clicking here.
