- In her 2016 autobiography, "Settle for More," the NBC host Megyn Kelly says she doesn't exercise and focuses instead on maintaining a high-fibre diet.
- Specifically, she says she adheres to the "F-Factor diet," designed by a dietitian named Tanya Zuckerbrot.
- There's science behind the diet, but it's not a great idea to cut out exercise completely.
Like many of us, Megyn Kelly doesn't have time to go the gym.
In a small section of her 2016 autobiography, "Settle for More," Kelly, the host of NBC's "Megyn Kelly Today" who formerly anchored shows on Fox News, describes how she stays svelte and healthy - and a workout routine isn't part of her strategy.
She wrote, "After I had my children, something had to give, and I gave up on exercise."
Now, Kelly says, she follows the so-called F-Factor diet, outlined in a 2007 book by a dietitian named Tanya Zuckerbrot.
"I started after the birth of my first child, Yates," Kelly wrote. "It took off the baby weight right away."
In her book, "The F-Factor Diet: Discover the Secret to Permanent Weight Loss," Zuckerbrot makes the case for a high-fibre diet and highlights two key benefits: One, fibre makes you feel full, so you end up eating less, and two, you're more inclined to stick with the regimen because you're adding foods to your diet rather than eliminating them.
Zuckerbrot explains that all your meals should include high-fibre carbohydrates and lean protein. By the time you complete all three phases of the F-Factor diet (each one lasts about two weeks), you should be eating a total of nine servings of high-fibre carbohydrates daily.
There's compelling research behind the F-Factor diet. Zuckerbrot cites a study published in the journal Nutrition Reviews that found that diets high in fibre and low in fat may be more effective than low-fat diets alone for weight loss.
Another study, published 2015 in the journal Annals of Internal Medicine, found that participants who increased their fibre intake to 30 grams or more a day lost as much weight as participants who followed a stricter set of dietary guidelines.
But the role of exercise in weight loss is complicated. One study, published 2012 in the journal PLOS One, suggests that people burn roughly the same amount of energy no matter how physically active they are. In other words, it matters more what you're putting into your body.
A small study published this year in the Journal of Endocrinology found that increasing the intensity and duration of your workout can help decrease hunger - at least in young men.
All that said, exercise is still an important part of a healthy lifestyle. And Zuckerbrot hardly advises readers to ditch their workouts.
"Combining the F-Factor diet with exercise is the most powerful formula for losing body fat," she writes, adding, "Dieting, or reducing your caloric intake, will result in dropping pounds, but keeping the weight off long term is almost impossible."
Even if, like Kelly, you feel you're too time-crunched to work out regularly, it's worth trying to squeeze it in when you can. That's true whether your goal is to lose weight or simply to be your healthiest self.