The statement was distributed after the president received his first physical since taking office at Walter Reed military hospital.
Will they show he's gained weight since his last medical report, which noted he tipped the scales at 236 pounds?
"I think it's going to go very well", Trump told reporters Thursday.
Buchinsky said he wouldn't be surprised if the president also underwent an electrocardiogram and stress test on a treadmill to determine his cardiovascular health.
But those hoping for answers, they may not learn much from the president's annual physical. But for the past several decades, all presidents have.
"Many of you yourselves have reported on the fact that the president exhibits yeoman-like work every day in this job", deputy press secretary Hogan Gidley told reporters Monday.
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.
But they also included more detailed examinations of the heart, lungs, vision, cholesterol and blood glucose that could point to problems.
The letter declared him in excellent health and listed his height as 6ft 3ins.
The fairly routine exam for previous presidents has taken on outsized importance in the age of Trump.
He also said Trump took Crestor, a cholesterol lowering statin; a low dose of aspirin to prevent heart attacks; antibiotics to treat skin rosacea; and Propecia for baldness.
Jackson, a Navy rear admiral, directs the White House medical unit and has worked as a White House physician since 2006.
Trump has claimed his physical health has always been strong. He uses a cart when plays golf. He doesn't smoke or drink alcohol. His diet is heavy on fast food, red meat and Diet Coke.
Trump, who is the oldest president to take office, in public appearances has slurred words and grasped a drinking glass with both hands.
Following this month's publication of a widely discussed, behind-the-scenes book about his first year in office, Trump on Twitter described himself as "a very stable genius" and earlier this week he allowed White House pool reporters and videographers to remain in the room for 55 minutes as he met with a group of senators with whom he was negotiating immigration legislation. Because the health information is considered private under federal law, the President himself must sign off on its release. With his physical set for next week, the president decided to make a prediction and give a warning [VIDEO]in the process.