Dr Ronny Jackson attributed Donald Trump’s “excellent” health to his “incredible genes” and said he is not concerned that the president only sleeps four to five hours a night.
I have no concerns about his cognitive ability or neurological functions,” Ronny Jackson said on Tuesday.
Last week, Mr Trump, 71, had a three-hour examination in his first medical check-up since becoming US president.
It comes after the release of a controversial book fuelled speculation about the president’s mental health.
Speaking to reporters during a White House briefing on Tuesday, Dr Jackson said that the president’s overall health was “excellent”.
“All data indicates the president is healthy and will remain so for the duration of his presidency,” he said.
“He continues to enjoy the significant long-term cardiac and overall health benefits that come from a lifetime of abstinence from tobacco and alcohol,” he added.
When asked by a reporter how a man who consumes fried chicken and Diet Coke and does not exercise could be in good shape, Dr Jackson replied: “It’s called genetics… He has incredible genes.”
However, Dr Jackson added that Mr Trump could benefit from a lower-fat diet and more exercise.
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On Friday, the president was examined by military doctors at the Walter Reed Medical Center in Bethesda, Maryland, in tests that were said to have gone “exceptionally well”.
Among them was Dr Jackson, whose official title is Physician to the President.
A rear admiral in the US Navy, he also tended to Mr Trump’s predecessor, Barack Obama.
To check for possible cognitive dysfunction, the US Department of Veterans Affairs uses the Montreal Cognitive Assessment (MoCA) neuropsychological test.
The MoCA test assesses an individual’s attention and concentration, memory, language, conceptual thinking, calculations, and orientation – among other functions.
According to Michael Wolff, author of Fire and Fury: Inside the Trump White House, all of the president’s White House aides see him as a “child” who needs “immediate gratification”.
Mr Trump responded by saying Wolff’s book was “full of lies”, while Secretary of State Rex Tillerson dismissed suggestions the president’s mental health was failing.
In December 2015, Mr Trump’s own long-time doctor, Harold Bornstein, declared in a pre-election assessment that his client would be the “healthiest individual ever elected to the presidency”.