(CNN) President Donald Trump was less than thrilled last year when his personal physician recommended he get on a diet, start exercising and set a goal of losing a dozen pounds.

The President famous for his love of fast food was reluctant to change his eating habits or use the White House fitness room that his most recent predecessors had used to stay in shape. But then he tasted the Dover sole prepared by the White House chefs.

"He was like, 'Sh**, I have to eat healthy?' And then he had this delicious Dover sole prepared at the White House and he really liked it," one White House official said.

But for a man in his 70s, with high cholesterol, a common form of heart disease and a penchant for burgers and fries, the occasional fish dinner might not have been all that his doctor ordered.

A little more than a year later, Trump will undergo his second physical exam as President on Friday at the Walter Reed military hospital. As he prepares for the battery of tests to evaluate his physical health, sources close to him say he has stuck with some minor changes to improve his diet. But an exercise regimen? That's remained elusive for the 72-year-old President.

"The President received a diet and exercise plan last year after his annual physical, but the President admits he has not followed it religiously," said Hogan Gidley, the principal deputy White House press secretary.

Lack of exercise

Nearly a dozen White House officials and sources close to Trump said they don't believe he's set foot in the fitness room in the White House residence, maintaining his view that exercise would be a waste of the energy he has always touted as one of his best attributes.

That's despite the insistence last year of his then-physician, Rear Adm. Ronny Jackson, that while the President was "more enthusiastic about the diet part than the exercise part...we're going to do both."

By comparison, Trump's most recent predecessors were exercise fiends . President Barack Obama played basketball until his knees began troubling him, switching later to cardio work on machines in the White House residence.

President George W. Bush asked for workout equipment, including an elliptical machine and dumbbells, to be installed in a poolside cabana steps from the Oval Office, and for a fold-up treadmill aboard Air Force One. He was also a fanatical bike rider.

White House aides, though, were confident that Trump had not followed his doctor's advice on exercise. Asked in a Reuters interview last summer about whether he was getting exercise, the President pointed to his infrequent walks from the White House to the Eisenhower Executive Office Building, a stone's throw away.

"I get exercise. I mean I walk, I this, I that," Trump said. "I run over to a building next door. I get more exercise than people think."

Trump has frequently hit the golf links during his presidency, about the only form of exercise he engages in, even though he uses a golf cart between holes. But the recent partial government shutdown cut into his golfing regimen, keeping him off the course for 69 straight days, a record during his two-plus years in office.

Red meat and fries

Even as Trump's diet has changed on the margins -- with White House chefs working with a dietician to create healthier meals -- the President still enjoys fast food and well-done red meat. When the Clemson University football team visited the White House last month, Trump hosted them with a spread of burgers, chicken nuggets and fries from a variety of fast food chains.

And during a visit to his hotel in Washington last week, the President dined on steak, shrimp and french fries, according to a person who saw him eating.

Trump has also summoned takeout food from his hotel, which aides or household staff collect and bring back to the White House, according to a person familiar with the orders. Those meals are also typically well-done steaks.

Asked by CNN about any changes to the President's diet, some people close to Trump said they had noticed none at all. Others said they noticed fewer meats and more fish on his plate.

Last year's physical

Questions about the President's health have hung over him throughout his presidency, but came into focus a year ago when his physical exam revealed he was borderline obese. A coronary calcium scan revealed he had a common form of heart disease . Jackson disclosed that Trump's LDL, or "bad cholesterol," levels were also rising, prompting the President's doctors to increase the dose of Crestor he was prescribed.

Despite all this, Jackson insisted Trump was in "excellent health."

Jackson's assessment of the President's health and his joke from the White House podium that Trump "might live to be 200 years old" if he improved his diet quickly came under fire from some medical professionals, including from within the White House's medical unit.

Four current and former White House Medical Unit staff members told CNN they were ashamed of Jackson's rosy assessment of Trump's health despite the publicly released data clearly showing a different picture.

"It was an embarrassment to military medicine," a former White House physician told CNN. "I thought it was really disingenuous. I really think that he was very scripted."

"You're being a hypocrite when you're saying he's in excellent health," the doctor added.

Jackson also revealed the results of a cognitive test, which Trump insisted on taking when questions over his mental acuity arose after author Michael Wolff described an erratic and scattered President, citing accounts from former aides and others. Jackson said Trump had received a perfect score on the exam, adding that such an assessment would not normally have been a part of the yearly physical, unless requested by the patient

While Jackson vouched for Trump's mental acuity, saying he found the President to be "very sharp," the Montreal Cognitive Assessment that Trump aced can be used to identify some cognitive issues like the early stages of dementia but is not intended to rule out all cognitive deficiencies or mental impairments.

Jackson's appearance in the White House briefing room was an anomaly; past White House physicians usually disclosed details of the President's health in paper form, declaring in brief statements that they found the commander in chief fit for duty but rarely expanding beyond a set of figures and results. The last White House doctor to brief reporters regularly in person was Dr. William Lukash, President Gerald Ford's physician.

The plight of Dr. Jackson

Trump, though, was thrilled with Jackson's turn at the White House podium, telling his aides as much over the next several days. Two months later, the President nominated Jackson to serve as secretary of veterans affairs.

But a series of allegations of improper behavior prompted Jackson to withdraw from consideration a month later, even as he rejected the allegations as "completely false and fabricated."

The allegations prompted the Defense Department's inspector general to launch an investigation into Jackson, but Trump hasn't wavered in his affinity for the smooth-talking Texan.

Even though Jackson remains the subject of an active Defense Department investigation, Trump promoted him on Saturday to the position of assistant to the President and chief medical adviser. He also resubmitted his nomination for Jackson to receive a military promotion to two-star admiral. That nomination will not move forward while the Defense Department investigation is ongoing, two Senate aides told CNN.

"President Trump, like former Presidents George W. Bush and Barack Obama, views Dr. Ronny Jackson as an excellent physician and trusted medical adviser," said one administration official. "In his new role as chief medical adviser, Dr. Jackson will transition from providing medical care to using his extensive medical expertise to provide technical policy advice to the executive branch."

New doctor, old habits

Though Jackson stepped down from his position as physician to the President after withdrawing as the Veterans Affairs nominee, he never left the White House medical unit.

Jackson, though, is not expected to take part in Trump's physical exam Friday.

Instead, the President's exam will likely be overseen by Dr. Sean Conley, a Navy commander who succeeded Jackson as physician to the President.

Conley, who served in Afghanistan, has kept a lower profile in the job. He's one of a rotating group of physicians who accompany the President on trips and plan for medical contingencies.

As of now, he is not expected to offer a public briefing on Trump's health, opting instead for a neat paper statement.

How much he reveals remains to be seen. As his patient, the President will need to sign off on any medical information released publicly.

Heading into the physical, Trump showed few signs he was making a last-minute effort to shed pounds. He did return to the golf course on Saturday, playing a round in Florida with two legends: Tiger Woods and Jack Nicklaus.

Afterward they returned to the clubhouse, where Trump's normal order includes either a cheeseburger or a few hot dogs.