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What is the F-Factor Diet and Why is Fiber Important for Weight Loss?

By Stephanie Eng-Aponte

Reviewed by Briana Rodriquez, R.D.


Have you heard of the F-Factor Diet? It capitalizes on one important thing that 95% of Americans1 aren’t getting enough of: fiber. 

So, what is the F-Factor Diet, exactly? Founded by Tanya Zuckerbrot, MS, RD, the F-Factor Diet’s goal is to help you lose weight. It emphasizes eating high-fiber foods and lean proteins, without making you give up carbs, fats or alcohol. But could it work for you? Find out how the F-Factor Diet works, why fiber is so important, and how you can use fiber to support your weight loss goals.  

Fiber 101 - Why fiber is important for weight loss

If gritty bran cereal is the first thing that comes to mind when you hear the word “fiber,” don’t worry — there are plenty of delicious, fiber-packed foods to choose from instead. 

Fiber is part of a healthy diet, and a diet high in fiber may help you achieve and maintain a healthy weight.2 There are two main types: soluble and insoluble. 

Fiber isn’t digested by the body the same way other foods are. Instead, it moves through your system, mostly intact.2 

Soluble fiber dissolves in water and turns into a gel-like substance, which slows digestion and helps promote feelings of fullness, which can be helpful for weight loss.3 Soluble fiber may also help to lower LDL cholesterol and blood sugar levels.2

Insoluble fiber doesn’t dissolve in water. Instead, it moves through your digestive system to help move waste out of your body. Foods containing insoluble fiber are naturally filling, which can be helpful for keeping your appetite under control.

Fruits, vegetables, grains, nuts and seeds are all great sources of dietary fiber and nutrients. Learn more about fiber and weight loss.

What is the F-Factor Diet?

Photo by FOODISM360 on Unsplash

cauliflower florets on green backgroundThe F-Factor Diet is a high-fiber, low-fat diet designed for weight loss.4 Dietitian Tanya Zuckerbrot created the F-Factor Diet after noticing the beneficial effects that a high-fiber diet had on her patients’ health and weight.5

The “F” in the F-Factor Diet stands for “fiber,” and with good reason: You’ll eat high-fiber meals to help keep calories down, while staying satisfied.6

On the F-Factor Diet, you’ll eat three fiber-rich meals each day that include healthy carbs and lean protein, plus one snack.7 There are three “Steps” in the program with different net carb requirements. 

Not sure what net carbs are? We’ll explain.

Net carbs: what they are & how to calculate them

Not all carbs are created equal.

“Net carbs describe the simple and complex carbs your body digests and absorbs, minus their fiber and sugar alcohol content,” says Briana Rodriquez, Registered Dietitian Nutritionist at Jenny Craig. 

“Tracking your net carbs allows you to see how many carbohydrates you’re actually digesting, because fiber isn’t digested by the body,” she explains.

This is why net carbs are a key part of the F-Factor Diet. If you follow the diet, you’ll use the program’s equation to calculate them:4

Grams of Total Carbs – Grams of Fiber = Net Carbs

For example, if you ate 65 grams of carbohydrates and 54 grams of fiber throughout the day (65 – 54), your net carb total would be 11 grams.

As you progress through the diet, you’ll increase the daily number of net carbs you’re allowed.4

  • Step 1: Stay under 35 grams of net carbs per day
  • Step 2: Eat a maximum of 75 grams of net carbs per day 
  • Step 3: Eat a maximum of 125 grams of net carbs per day 

With the F-Factor Diet, fiber is definitely in your future

How much fiber you’ll eat on the F-Factor Diet: During Step 1, your goal is to eat 35 grams of fiber every day, at minimum.4 The diet doesn’t limit how much fiber you can eat per day.

How much fiber should you really be eating? The Food and Drug Administration’s (FDA) daily fiber recommendation is 25 grams, based on a 2,000-calorie diet, but the amount of fiber you should have may vary, depending on your calorie needs.8

You’ll be encouraged to create a food journal to track your meals, which you’ll use to log your total carbohydrates and fiber and calculate your net carbs. 

What about exercise?

The F-Factor diet doesn’t require exercise, but strength training is recommended over cardio.9

“Balanced nutrition should come first if you want to lose weight and live a healthy lifestyle,” Rodriquez says, “but cardio and strength training are both important for weight loss and health — don’t pass up one for the other.” 

While cardio exercise is great for heart health, strength training helps to build muscle. Plus, muscle burns more calories than fat at rest, which could help you to maintain your weight in the long run. (Here’s how to start your own strength training routine.)

Balance is key

It’s true, you don’t need to cut out carbs to lose weight. But the type and amount of carbohydrates you eat, along with the other foods you incorporate into your diet, are crucial.

The F-Factor Diet’s emphasis on high fiber and lean protein is a good thing, says Rodriquez, but she cautions that upping your fiber content drastically can have an uncomfortable outcome.

Gas, bloating and abdominal pain are all common side effects of too much fiber, so it’s important to stay well hydrated.10

And rather than overdoing it with fiber supplements, try to eat a variety of fiber-rich foods instead, focusing on non-starchy vegetables (broccoli, celery, mushrooms, tomatoes, and more), fruits and legumes, Rodriquez suggests. High-fiber foods (like non-starchy vegetables) can add volume to your meal without loading on the calories, which is helpful for weight loss.

If you’re following the F-Factor Diet without the guidance of Zuckerbrot or her nutrition team, you may need to do a little research to follow the diet to a T. The high fiber diet currently doesn’t have pre-planned menus, so you’ll need to cook, portion and track your meals and snacks on your own, paying careful attention to the Nutrition Facts labels to find out how many net carbs you’re consuming. If you're looking for a pre-planned meal plan, check out Jenny Craig's 7-day diet plan for weight loss. 



A fiber-rich diet can be convenient (and good for weight loss!)


Jenny Craig Cheesy Chicken Rice BowlIf you’re not sure how much fiber you should have to support your weight loss goals, Jenny Craig can help! You won’t be required to track calories or net carbs to live a balanced lifestyle — we’ll do all the hard work for you.

Easy-to-follow menus

Jenny Craig’s dietitian-designed weekly menus aim to provide a minimum of 25 grams of fiber per day, says Rodriquez, so you’ll be well within the FDA’s recommendations. Plus, you'll eat plenty of non-starchy vegetables that are filled with good-for-you fiber. 

Eat 6X a day

Delicious, ready-to-go foods won’t weigh you down — or keep you in the kitchen. Entrées are ready in minutes, so you can savor your meal and get back to your day. 

Enjoy flavorful American comfort food, Asian-inspired dishes, Italian-style classics, and more, plus snacks and shakes, all conveniently portioned to help you stay on track. The fiber content in Jenny Craig foods can vary, so you’ll balance them with servings of nutrient-dense fruits and vegetables. Check out these popular entrées that are good sources of fiber:

Get the support you need

You don’t need to figure out how to lose weight on your own! You’ll have the support of a dedicated weight loss coach to guide you along the way. Chat with your coach to walk through your menu, pick up your food (or get it delivered right to your door) and talk through your plans for the week. If you have any questions about your plan (including how much fiber certain foods have), ask your coach or contact a Jenny Craig team member by contacting us directly

Learn healthy habits for life

Once you reach your goal, we’ll be here for you, too. You’ll take the tools you’ve discovered throughout your weight loss journey and learn more strategies to help you maintain your weight

Ready to give Jenny Craig a try? Learn more about adding healthy sources of fiber to your diet to help support your weight loss goals and get the tools you need to succeed: Chat online with a Jenny Craig weight loss coach to get started today!





[1] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6124841/
[2] https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/fiber/art-20043983
[3] https://medlineplus.gov/dietaryfiber.html
[4] https://www.ffactor.com/living-ffactor-calorie-counting/
[5] https://www.ffactor.com/our-founder/
[6] https://www.ffactor.com/what-is-f-factor/
[7] https://www.goodhousekeeping.com/health/diet-nutrition/a27508457/f-factor-diet/
[8] https://www.accessdata.fda.gov/scripts/interactivenutritionfactslabel/factsheets/dietary_fiber.pdf
[9] https://www.ffactor.com/press/eat-not-9-ways-megyn-kelly-stays-slim-45/
[10] https://www.healthline.com/health/food-nutrition/too-much-fiber

Stephanie Eng-Aponte

Stephanie Eng Aponte
Stephanie Eng-Aponte is a copywriter for Jenny Craig and has written for the health and wellness, tech, and environmental industries. Stephanie graduated from Rutgers University with a Bachelor of Arts degree in Journalism and Media Studies. They employ an “eat first, write later” approach to food blogging and enjoy the occasional Oxford comma. Outside of writing, you can find them photographing a muttley crew of rescue pups, brewing kombucha, or exploring San Diego.

Favorite healthy snack: green apple slices with sunflower butter


Reviewed by Briana Rodriquez, RDN

Briana Rodriquez, RDN
Briana is a Registered Dietitian Nutritionist and Certified Personal Trainer for Jenny Craig, based in Carlsbad, California. She is passionate about utilizing food as functional and preventative medicine. Guided by a simplistic and optimistic approach, Briana’s philosophy is to help people improve their health and achieve their goals through the development of sustainable habits to live a healthy life. In her free time, you can find her strength training, indoor cycling, coffee tasting, and at local eateries with her husband and two dogs. 


Favorite healthy snack: peanut butter with celery alongside a grapefruit-flavored sparkling water (so refreshing!) 



This article is based on scientific research and/or other scientific articles and was written by an experienced health and lifestyle contributor and reviewed by certified professionals. 


Our goal at Jenny Craig is to provide the most up-to-date and objective information on health-related topics, so our readers can make informed decisions based on factual content. All articles undergo an extensive review process, and depending on the topic, are reviewed by a Registered Dietitian Nutritionist (RDN) or Nutritionist, to ensure accuracy. 


This article contains trusted sources including a scientific, peer-reviewed paper. All references are hyperlinked at the end of the article to take readers directly to the source. 


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