Top US Democrat Nancy Pelosi has been accused of fat-shaming President Donald Trump after she called him "morbidly obese".
Mrs Pelosi cited Mr Trump's "weight group" when asked about his disclosure that he is taking hydroxychloroquine to guard against Covid-19.
There is no evidence the drug can ward off the virus, and experts have cautioned it may cause heart problems.
Critics said Mrs Pelosi's "fat-phobic" response distracted from such concerns.
The World Health Organization has called attention to reports of individuals self-medicating and causing themselves serious harm with hydroxychloroquine, which Mr Trump has repeatedly touted as a potential Covid-19 treatment.
Speaking to reporters on Monday, the 73-year-old president said he had started taking the malaria and lupus medication in the past fortnight.
"I happen to be taking it," Mr Trump said. "If it's not good, I'll tell you right, I'm not going to get hurt by it."
Asked on Monday night by CNN about Mr Trump's remarks, Mrs Pelosi said she would "rather he [Mr Trump] not be taking something that has not been approved by the scientists".
"Especially in his age group, and in his, shall we say, weight group, morbidly obese, they say," the US House of Representatives speaker said.
Epidemiologist Abdul El-Sayed, a CNN commentator, tweeted on Tuesday that Mrs Pelosi's remarks would only reinforce the stigma around obesity.
Sorry, calling Trump #morbidlyobese just ain't it.— Abdul El-Sayed (@AbdulElSayed) May 19, 2020
It perpetuates a culture of political mudslinging that allows honest criticism of the dangerous things he's done to be dismissed as petty partisanship.
Also, fat-shaming drives obesity stigma. It's not cool or funny.
Others argued that Mrs Pelosi - Mr Trump's most powerful elected antagonist - should focus on legitimate criticisms of how the president has handled the pandemic.
Always good to wake up to the Dems making fat jokes to dunk on the president.— josie duffy rice (@jduffyrice) May 19, 2020
Nancy Pelosi calling the president "morbidly obese" may initially feel like "AYYY GOT EM" but, while fat positivity is a complex issue, it sets a classless precedent. Attack him on the merits, absolutely, but why stoop to his level AND shame fatness? All for one lousy cheap shot?— Brent Black (@brentalfloss) May 19, 2020
But others pointed out that the president has made a number of derogatory comments about women's appearances, including fat-shaming.
He once called former Miss Universe Alicia Machado "Miss Piggy" and defended the remark by saying: "She gained a massive amount of weight and it was a real problem."
He has repeatedly insulted his longtime celebrity adversary Rosie O'Donnell, once calling her "fat, ugly".
On Tuesday, after initially declining to respond to Mrs Pelosi, Mr Trump said she has "mental problems".
"Pelosi is a sick woman. She's got a lot of problems," the president told reporters.
Last year, the White House physician noted in Mr Trump's annual medical exam that the president weighed 243lb (110kg) and was 6ft 3in, which would score his body mass index at a technically obese 30.4.
Mr Trump and Mrs Pelosi have exchanged insults throughout the Republican's presidency, often focusing on the other's mental fitness.
In May of last year, she called on his family to conduct an intervention for "the good of the country". Mr Trump responded by calling Mrs Pelosi "crazy" and "a mess".