A Fox News co-host questioned Michelle Obama's weight and eating habits on Tuesday as the first lady advocates for nutrition standards through her "Let's Move" anti-obesity campaign.

"How well could she be eating? She needs to drop a few," Keith Ablow, a psychiatrist and member of Fox's "Medical A-Team," said on "Outnumbered."

The show regularly features four women sitting on a couch with one man in the middle, who's "outnumbered" in conversations about the news.

After the four female co-hosts chided Ablow for his comments, he continued to offer skepticism.

"Well, no, let's be honest. I mean, there's no French fries ever? That's all kale and carrots? I don't buy it," he said.

One co-host, Lisa 'Kennedy' Montgomery, jumped in to defend the first lady.

"I do not like her attitude, but I like her booty," she said.

Sandra Smith, another co-host, tried to drive the discussion back to the topic at hand - some school districts are opting out of federal requirements that mandate better choices for school lunches, saying the requirements are too difficult.

Smith added that some students are simply leaving campus to buy fast food, rather than buy food they don't want to eat at school.

Congressional Republicans have been trying to nix or delay the program.

Ablow jumped in again: "Exactly, but that's what she's doing. She's up at night in the White House kitchen, I'm telling ya."

CNN has reached out to the White House for comment on the host's remarks.