US physician Mehmet Oz has revealed that President Donald Trump believes diet fizzy drinks destroy cancer cells within the body.

Speaking to the president's son Donald Trump Jr on his podcast Triggered, Dr Oz, Administrator for the Centers for Medicare and Medicaid Services, said: "Your dad argues that diet soda is good for him because it kills grass... so it therefore must kill cancer cells inside the body."

There is no scientific evidence whatsoever to support President Trump's assertion that diet soda kills cancer.

This is far from the first occasion on which Trump's dietary choices have come under scrutiny from those close to him.

US Health Secretary Robert F. Kennedy Junior has described the president as having the most "unhinged" eating habits of anyone within his administration.

Just days after the launch of the Trump administration's "Make America Healthy Again" dietary guidelines, which recommends significant reductions in the consumption of processed foods, Kennedy passed comment on Trump's eating habits.

The 79 year old president is well known for his love of fast food. During a podcast interview with Katie Miller, wife of White House deputy chief of staff Stephen Miller, in January, Kennedy was asked who has the most "unhinged" eating habits, to which he replied: "The president.

"The interesting thing about the president is that he eats really bad food – which is McDonald's and then candy and Diet Coke," RFK Jr said.

"He drinks the Diet Coke all the times... I don't know how he's alive, but he is." Kennedy revealed that Trump exclusively consumes junk food while travelling, as he believes he can trust food from major corporations and wishes to avoid falling ill. Kennedy noted that when at Mar-a-Lago or the White House, Trump eats 'really good food'.

"If you travel with him you just get the idea that he's pumping himself with poison all day long and you don't know how he's walking around, much less being the most energetic person any of us have ever met."

In October 2025, Republican National Committee chair Joe Gruters revealed that Trump assembled his own bespoke McDonald's super-burger while out on the campaign trail in 2024, combining elements from two separate meals into one custom creation.

"He had a Filet-o-Fish, a Quarter Pounder, a Big Mac, and I think he combined two of them," Gruters said at the time. "How does a guy that is as senior as him get away with eating all this McDonald's probably on a consistent basis?"

Heavy consumption of processed foods has been strongly linked to chronic conditions such as diabetes and obesity — precisely the issues that Trump and Kennedy's "Make America Healthy Again" movement is striving to combat.