The note, which Trump, 77, posted on his Truth Social account, was released on the same day as Democratic President Joe Biden's 81st birthday. The physical and mental health of both men has become a major issue in the 2024 presidential race.
"President Trump has reduced his weight through an improved diet and continued daily physical activity, while maintaining a rigorous schedule," read the note, which was signed by Bruce Aronwald, an osteopath from New Jersey.
The note provided no further details.
"His physical exams were well within the normal range and his cognitive exams were exceptional," Aronwald wrote.
Trump is leading the Republican nominating contest by far, and Biden has said he plans to run for reelection.
A Trump physician, Harold Bornstein, who produced a similar note in 2016 said that Trump had dictated its contents.
Trump indicated he weighed 215 pounds (98 kg) and was 6 feet 3 inches (1.9 meters) in August when he was booked at an Atlanta jail on more than a dozen felony charges as part of a wide-ranging criminal case stemming from the former U.S. president's attempts to overturn his 2020 election defeat in Georgia.
Trump has pleaded not guilty in that case and three other criminal cases against him.