Jillian Michaels dishes out new diet advice: Fast for 12 hours and eat only one snack a day

Jillian Michaels came after CrossFit and keto, and now she's coming after your snacks.

The former "Biggest Loser" trainer published an article Tuesday in Women's Health Magazine suggesting that you should only be eating during a 12 hour period each day.

"So let’s say there are 12 hours a day when you’re fasting, and 12 hours a day when you’re eating," Michaels writes. "Break that down and you’ll need to eat about every three to four hours. That’s just enough time for breakfast, lunch, ONE snack, and dinner."

The 12 hour fasting period includes sleeping time.

What Michaels is suggesting isn't new. It's commonly referred to as intermittent fasting, which means alternating between certain periods of eating and not eating. The method of dieting has been used as a way to lose weight and for other benefits. A study from The National Institute on Aging last year suggests that intermittent fasting could be the key to longevity.

Benefits of intermittent fasting: Can I lose weight intermittent fasting?

Mark Mattson, professor of neuroscience in the Johns Hopkins School of Medicine, told Johns Hopkins Health Review that fasting several days a week could ward off Alzheimer’s and Parkinson’s, and also improve memory and mood. Donald D. Hensrud at Mayo Clinic College of Medicine wrote in 2014, regular fasting could help cholesterol, and reduce "risk of gaining weight and developing diabetes."

Michaels, meanwhile, had a lot of specifics to share regarding the one snack she recommends per day. It should be comprised of "40 percent carbs, 30 percent fat, and 30 percent protein" and should make up 20 percent of your daily caloric intake.

Michaels cautioned even seemingly healthy snacks like avocados can result in weight gain.

"That half an avocado you just ate for a snack might have 400 calories, and those extra calories add up," she writes. "So yeah, even healthy foods aren’t necessarily always good for you."

She continues: "Don’t mistake that cereal bar that’s on your points plan for a healthy snack. It’s not. It’s a processed diet food, and it’s garbage. It has no nutrient value, it doesn’t have a good blend of macros, and it doesn’t have fiber or healthy fats for good energy."

Jillian Michaels comes after CrossFit: Jillian Michaels, who slammed the keto diet, bashes CrossFit: 'It stops being effective'

Earlier this year, Michaels came under fire for bashing the keto diet, the trendy weight-loss regimen tied to everyone from Al Roker to Halle Berry because she says it starves the body's cells of essential macronutrients.

"I don't understand. Like, why would anybody think this is a good idea?" Michaels, 44, told Women's Health magazine, calling the keto diet a "bad plan, for a million reasons."

According to Michaels, the high-fat, low-carb diet ignores the reality that "your cells, your macromolecules, are literally made up of protein, fat, carbohydrates, nucleic acids," and can threaten the body's overall health.

Roker, the high-profile "Today" weather anchor, took to Twitter to slam Michaels for her remarks.

"So @JillianMichaels says #Keto is a bad idea. This from a woman who promoted on camera bullying , deprivation, manipulation and more weekly in the name of weight loss," he tweeted last week. "Now those sound like bad ideas."

Contributing Cydney Henderson, Ashley May and Dalvin Brown

This article originally appeared on USA TODAY: Jillian Michaels says to fast for 12 hours a day, eat one snack a day