The NBC weatherman took to Twitter on Thursday to call out Michaels for her recent comments slamming the ketogenic diet. The celebrity trainer criticized the popular diet earlier this week, saying it was a bad plan "for a million reasons" -- and Roker didn't hold back in his response. In his scathing tweet at Michaels, Roker took aim at her past on The Biggest Loser, referencing her controversial behavior on the show as a "bad idea."
"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. Now those sound like bad ideas," he wrote.
Roker, who started the keto diet in September, defended the nutrition plan -- which focuses on a low-carb, high-protein diet -- more on Friday's Today show. He said that his health has been great since starting keto, and also revealed that Michaels had emailed him in response to his tweet -- but shared that he didn't want to divulge her message.
"My point is, what works for you, works for you,'' he said on Today. "There's science on both sides that says it's not a great idea and science that says it is a great idea."
"I think it's up to people, with their doctor, with their medical professional [to make their own decision]," Roker added.
Michaels responded to Roker on Friday, offering to debate him on the keto diet, but also slamming him for his "personal attacks" on her.
"It's bizarre, it's unnecessary, it's beneath both of us," she said in a video she tweeted. "Read my book, The 6 Keys. I've extensively researched everything in that, and nutrition is about way more than weight loss."
In her interview with Women's Health earlier this week, Michaels explained the reasoning behind her aversion to the keto diet.
“Your cells, your macromolecules, are literally made up of protein, fat, carbohydrates, nucleic acids," she noted. "When you do not eat one of the three macronutrients -- those three things I just mentioned -- you’re starving yourselves. Those macronutrients serve a very important purpose for your overall health and wellbeing -- each and every one of them.”
See more on celebrity diets in the video below.