"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.
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.