A doctor has made a shocking admission about NASA astronaut Sunita Williams’ appearance following her return from space less than two weeks ago.

After spending 288 days in space, Williams and crewmate Butch Williams looked frail and gaunt when they splashed down off the coast of Florida on March 18.

Research by former astronauts suggests that it could take up to 1.5 times the duration of the mission to reverse the effects of long-term exposure to low gravity. This means it might take the pair up to a year to fully recover.

During their first interview on Fox News, pulmonologist and Air Force veteran Vinay Gupta noted that Williams’ appearance seemed to have improved, with her face appearing fuller and less sunken after returning from space.

‘It looks like she just has gotten better sleep,’ he added. ‘She’s back on level ground. Her metabolism is normalizing to sort of normal gravity.’

He also noted that her body is not undergoing the same stress as it was while on the International Space Station (ISS) that sits more than 230 miles above Earth’s surface. 

‘She’s probably just eating healthier and is able to sort of modulate and gain back some weight,’ the doctor continued. ‘I think two weeks has probably been sufficient to look just healthier.’

Williams and Wilmore spoke later during a NASA press conference where she even said her recovery has been ‘miraculous.’

Striking images taken right after Williams left the SpaceX Dragon capsule that brought her and Wilmore home showed her with noticeably grayer hair, deeper wrinkles, and a more gaunt face.

Hours later, the astronaut’s condition raised even more concern after medical experts spotted Williams’ ‘visibly thin’ wrists, which they told DailyMail.com could be a sign of rapid weight loss, muscular wasting in her arms, and bone density loss.

Dr Gupta, and many other medical professionals, said Williams and Wilmore are likely to need up to six weeks of rehab to get back into basic shape after living in low gravity for so long.

While their bodies may still be recovering, Williams’ appearance is nearly close to what it was before the launch on June 5.  She seemed to have put on weight and also dyed her hair back to a dark brown, adding more life into her face.

Dr Gupta said he was confident that the astronauts are basically past the recovery phase already.

‘I think the worst is probably well behind them,’ the doctor explained.

‘The second you’re back on level ground, your body starts to heal and sort of re-equilibrate,’ he said.

Williams and Wilmore were initially scheduled to spend eight days on the ISS when they launched aboard Boeing’s Starliner spacecraft for the capsule’s first crewed test flight.

While the two astronauts safely reached the space station, the problem-plagued Starliner immediately began to experience serious technical issues.

By the time they had reached the station, five of Starliner’s 28 thrusters failed and the craft had begun to leak helium – the same problems that had been delaying the Boeing project for years.

When it became clear that Starliner could not bring the astronauts home safely, the capsule was sent back to Earth uncrewed and without a clear plan in place to bring the stranded astronauts home.

The duo would end up spending over nine months (286 days) on the station in Earth orbit.

However, both Williams and Wilmore began showing the physical toll of being marooned on the ISS longer before returning to Earth in March.

In November, an unnamed NASA source told the New York Post that the agency was scrambling to ‘stabilize the weight loss and hopefully reverse it.’

The unnamed employee who is ‘directly involved with the mission’ said that Williams has been ‘unable to keep up with the high-caloric diets that astronauts must consume’ while on the ISS. 

‘The pounds have melted off her and she’s now skin and bones. So it’s a priority to help her stabilize the weight loss and hopefully reverse it,’ the NASA source said.

To that point, Dr Gupta said the diets of these astronauts when they were back on Earth may have had a lot to do with their stamina in space. 

On Monday, Williams noted in a NASA press conference that her father was a vegetarian and that her first meal after returning from ISS was a grilled cheese sandwich.

Dr Gupta explained that if Williams was shying away from meat-based proteins, this could have caused her health issues over the nine months in space.

‘Meaty sources of fat or protein tend to be fattier, take longer to digest, tend to power up your metabolism for more rigorous activity,’ Gupta noted.

Wilmore, however, appeared to maintain his weight and complexion throughout their long stay in space.

NASA and the astronauts have not publicly revealed if they have vastly different diets, so it’s unknown if their meal choices played a role or not.

‘If there was such a difference between what they were intaking. It does not surprise me at all that Sunita looks looked visibly thinner than her counterpart,’ Dr Gupta said.