Dr Jackson has worked in the White House since 2006 where he previously treated senior staff and cabinet members.
US President Donald Trump received a flawless score in a cognitive function test used to detect a mental decline in someone who's otherwise healthy.
A senior White House official said Trump does not believe he has an ally on this issue in Graham, a Republican who has long tried to partner with Democrats on immigration legislation.
"I think a reasonable goal over the next year or so would be to lose 10 to 15 pounds", Jackson said.
Trump also will increase his daily dosage of Crestor, Jackson said, with a goal of getting his LDL cholesterol down to below a reading of 120.
"It's called genetics. I don't know".
The dispute erupted last week after reports surfaced in the U.S. media that during a meeting at the White House, Trump had asked: "Why are we having all these people here from" shit-hole "countries??". Also concerning are Trump's total cholesterol levels and his LDL ("bad" cholesterol), as both increased significantly over the a year ago, despite being on a statin drug known as Crestor or Rosuvastatin.
Trump even demonstrated above-average exercise capacity despite his famous aversion to physical activity other than golf, Jackson 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", Jackson wrote.
Jackson said, "Some people exercise, some people don't. Some people have great genes".
"I get exercise. I mean I walk, I this, I that", Trump said in an interview with Reuters Wednesday, a day after Dr. Ronny Jackson released his assessment of the president's physical activities.
Trump has also said on multiple occasions that the bodies of people around him who do exercise are always breaking down.
Not expected are any conclusions about Trump's mental acuity.
Recent controversy over Michael Wolff's book Fire and Fury has led to speculation about the president's fitness for office, prompting Mr Trump to declare himself "a stable genius" on Twitter.
During the presidential campaign, Trump's long-time personal physician, Harold Bornstein, had declared that Trump would be "the healthiest individual ever elected to the presidency".
Jackson said Trump dozes four to five hours for every night, and takes Propecia for counteractive action of male pattern baldness.
That could be due to two factors, Jackson said. To figure out what causes the worrisome traits President Trump exhibits - disordered decision-making, an insatiable need for affirmation, little impulse control, confusion about facts, difficulty foreseeing consequences - you'd need more extensive tests, a psychological exam and an MRI.
Dr Jackson revealed last week that the check-up at the Walter Reed military hospital in Bethesda, Maryland, had gone "exceptionally well", adding that he was "enthusiastic" about sharing further details.
This story was first published on CNN.com, "White House doctor: "No concerns" about Trump's cognitive ability".