WASHINGTON - The White House physician pronounced Donald Trump to be in "excellent health" after Trump had his first medical exam as US president on Friday, capping off a week in which his mental fitness for the job has come under intense scrutiny.Trump spent about three hours with military doctors at the Walter Reed National Military Medical Center in Bethesda, Maryland, an exam that White House doctor Ronny Jackson said went "exceptionally well." "The president is in excellent health and I look forward to briefing some of the details on Tuesday," Jackson said in a brief statement distributed by the White House.The exam came after a new best-selling book portrayed Trump, 71, as unfocused and childlike. The White House has faced a barrage of questions over his contradictory messages on key policies and an incident last month where he slurred some words while giving a speech.The White House determines what data will be released from the exam. Trump is not compelled to release any information, and there is no template for the presidential exam. Jackson is expected to take questions about the results from reporters on Tuesday.Past presidents are not known to have been tested for mental acuity while in office - including Ronald Reagan, who five years after leaving the White House was diagnosed with Alzheimer's disease.The White House had made clear that Trump's examination would not include a psychiatric exam. Results of past presidential physicals have included basic data like weight, blood pressure and cholesterol levels.There is a long history of the White House picking and choosing what to reveal about the commander in chief's health, said Barbara Perry, director of presidential studies at the University of Virginia’s Miller Center.For example, John F. Kennedy disclosed war injuries but not the fact he suffered from Addison's disease, a degenerative condition.Perry said she believed presidents should be subject to a raft of tests to establish they are fit to serve.When he was running for office, Trump released a glowing report from his personal physician in New York, who said Trump would be "the healthiest individual ever elected to the presidency." The public report from Trump's upcoming exam was also likely to be short and sweet, said George Annas, head of the Center for Health Law, Ethics and Human Rights at Boston University School of Public Health."I don’t think you could expect to see anything else, unless it’s something that makes him look good," Annas said.