These high-fiber crackers are all the rage. What to know about them

If you see a cracker made in Norway taking over your Instagram feed, you're not alone.

The #ggcrackers hashtag for GG Scandinavian Bran Crispbread, a 20-calorie cracker beloved for its high-fiber content -- currently has more than 1,000 posts and counting.

The crackers are practical works of art on Instagram, topped with everything from avocado to eggs, fruit and salmon.

The woman behind the crackers' popularity in the U.S. is Tanya Zuckerbrot, a New York City-based dietitian and founder of the F-Factor Diet, a weight loss and health program focused on the nutrients of fiber.

"I think it’s more fiber that is what’s really being embraced and therefore this [GG crackers] is a vehicle to get fiber into your diet," explained Zuckerbrot, who said she saw the crackers go viral on social media just in the last year, when she started posting topping variations and recipes on Instagram.

Zuckerbrot discovered the crackers 20 years ago on the bottom shelf of a health food store covered in dust, she recalled. At the time, she was working with diabetic and cardiovascular patients in a clinical private practice setting and was looking for a bread alternative.

"I blew the dust off to look at the nutrition label," said Zuckerbrot, who added the crackers to her clients' diets. "All these clients returned to their cardiologists and endocrinologist and found not only were they healthier but they were all losing weight without hunger."

Zuckerbrot thinks eating fiber was the key to her clients' success.

"That was the birth of the F-Factor Diet," she said.

Each GG cracker contains four grams of fiber and 20 calories, according to the package's nutrition label.

The recommended dietary fiber intake per day is 25 grams for women and 38 grams for men. Consuming fiber well beyond those recommendations could lead to abdominal pain, bloating and gas and mineral deficiencies in some cases, experts say.

Zuckerbrot featured the GG crackers in her first book, "The F-Factor Diet," published in 2006, and has watched them explode in popularity since.

"They are a vehicle to get fiber in because you want the benefits of fiber," said Zuckerbrot, who is now launching her own line of fiber-filled foods.

Zuckerbrot, whose clients have included Megyn Kelly, Katie Couric and Miss USA 2012 Olivia Culpo, advises people on the F-Factor Diet to eat between 35 and 60 grams of fiber per day.

Zuckerbrot even sells a $45 carrying case to hold the high-fiber crackers, and other F-Factor-approved snacks. She has never received compensation from the maker of the GG crackers, but is now exploring partnership ideas with the company to coincide with the release of her third book, an updated edition of "The F-Factor Diet."

Though the crackers are now popular on social media, they are not a 21st century creation.

The crackers’ namesake, Gunder Gundersen, first created the recipe for the crackers in 1935 in his native Norway, according to the company’s website.

The crackers are still made in Norway and now include variations like sunflower seed and pumpkin seed.

GG's website includes recipes for everything from salmon to pancakes, pumpkin muffins, pizza and meatloaf, with GG Scandinavian Bran Crispbread as the main ingredient.

Heather Bauer, a registered dietitian nutritionist, also recommends GG crackers to her clients.

"I like them because they give you crunch and texture but they don’t have that binge-able quality," said Bauer, also the founder of the weight loss program The Food Fix. "They're an effective way to get fiber in without putting in too many calories."

Bauer warns her clients to not turn the GG crackers "into a party."

"You can turn them into a party if you slather them with peanut butter or brie cheese," she said. "You defeat the purpose of them."

Instead, top the crackers with avocado or eggs for breakfast, almond butter or light cheese for a snack, or crumble them in a salad as a crouton replacement, advises Bauer.