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The “F” in F-Factor diet does not stand for fad. Registered dietitian Tanya Zuckerbrot’s book The F-Factor Diet: Discover the Secret to Permanent Weight Loss, first came out in 2006, and her fiber-fueled approach to healthy eating has now stuck around for over a decade. Many celebs (like Katie Couric) have tried the plan, and unlike other trendy “detoxes”, this method actually has solid science behind it that could help you lose weight — for good.
“What I love about F-Factor is that it creates a plan in which eating real, wholesome foods and prioritizing nutrient-dense meals and snacks is simple and adaptable to your personal needs and habits — without eliminating anything or requiring some type of extreme restriction,” says Jaclyn London, MS, RD, CDN, Nutrition Director at the Good Housekeeping Institute.
Here’s what else you should know about the F-Factor Diet.
What is the F-Factor diet?
The F-Factor diet focuses on getting enough fiber in your diet. What’s so magical about fiber? “It’s a non-digestible carbohydrate that’s found in the world’s best, most nutritious foods — veggies, fruit, legumes, nuts, seeds, and 100% whole grains,” London says.
After years of working with clients with diabetes and heart disease, Zuckerbrot realized that eating more fiber helped people not only manage blood sugar levels and lower cholesterol, but also lose weight. Besides appearing in a slew of good-for-you-foods, fiber also fills you up so you’re not feeling deprived.
“These patients were simply feeling fuller throughout the day on fewer calories, which led to weight loss without hunger,” Zuckerbrot said in an interview with Camille Styles.
The plan prescribes eating three fiber-filled meals and a snack each day, loading up on healthy carbs and lean protein, but also enjoying meals out and the occasional drink. In order to maintain long-term success, you’re not supposed to restrict and deprive — hence the “permanent” part of the title. You can get all the specifics in the book, but the plan includes three general phases:
- Jumpstarting Weight Loss: Eat 35 grams of fiber and less than 35 grams of net carbs (3 servings) per day.
- Continued Weight Loss: Aim for at least 35 grams of fiber and less than 75 grams of net carbs (6 servings) per day.
- Maintenance Eating: Aim for at least 35 grams of fiber and less than 125 grams of net carbs (9 servings) per day.
How many grams of fiber should I eat on the F-Factor Diet?
At each stage of the F-Factor diet, you should aim to eat at least 35 grams of fiber per day. That’s not an arbitrary number. The Dietary Guidelines for Americans recommends adults consume between 28-35 grams of fiber daily depending on your age and gender. However, only a mere 5% of us of get close to that goal, according to a 2017 study published in the American Journal of Lifestyle Medicine.
What do you eat on the F-Factor Diet?
No food is officially off-limits on the F-Factor diet. Instead, it’s all about adding more fiber-full vegetables, fruits, beans, and whole grains to your plate.
That said, the first phase of the diet asks you to avoid starches and starchy vegetables, most dairy, and fatty meats. However, this part lasts for only two weeks. After that, you can move on to Phase 2 and Phase 3, which place no restrictions on any foods — but you do need to hit that 35 grams of fiber benchmark.
Do so by loading up on these fiber-full foods, as listed by the Dietary Guidelines for Americans:
- Pulses: beans, peas, chickpeas, lentils
- Whole Grains: bulgur, quinoa, barley, whole-grain bread, high-fiber cereal, shredded wheat cereal, bran cereal, rye crackers, whole-wheat pasta, air-popped popcorn
- Fruits: apples, pears, raspberries, blackberries, figs, oranges, bananas, guava, dates
- Vegetables: artichokes, avocado, collards, sweet potato, pumpkin, parsnips, squash
- Nuts and Seeds: pumpkin seeds, chia seeds, sunflower seeds, almonds, pistachios, pecans, hazelnuts, peanuts
“Whether you’re opting in on F-Factor or not, choose foods that are in their most wholesome state as possible, within the confines of your budget and palate,” London advises. “Oranges versus orange juice, roasted veggies versus veggie chips, and so on.”
Does the F-Factor Diet really work?
Yes, the F-Factor diet can help you lose weight if that’s your goal. “Fiber, specifically, is essential to success on the F-Factor diet, as it allows you to eat the carbohydrates necessary for energy without gaining weight,” Zuckerbrot told Camille Styles. “When you follow a diet rich in fiber you feel full after eating – so you’ll generally eat less throughout the day.”
The plan can also benefit you in other ways. “While it’ll work for weight loss, the tenants of the plan make it sustainable for anyone to make healthier choices because the program has you prioritizing real, whole foods that are nutrient-dense — without being a complete snooze,” London says.
She loves that it promotes eating more pulses, veggies, whole grains, and fruit, but cautions that framing everything in terms of “fiber” could let you lose sight of eating and enjoying actual food.
“Prioritize wholesome, nourishing foods before re-thinking everything you eat in terms of the nutrients it contains,” London advises. “We benefit from nourishment from multiple sources and experiences — enjoying food should be front and center, not just focusing on one single nutrient!”