NASA is trying to stabilize astronaut Sunita Williams' weight

NASA doctors are desperately trying to help stranded astronaut Sunita Williams gain weight after she suffered “significant” weight loss since arriving at the International Space Station in June.

Newly released photos show the 59-year-old Williams looking noticeably gaunt, with sunken cheeks and a noticeably thinner figure.

“She lost a lot of weight,” said a NASA official directly involved in the mission who took part in several briefings.

“The pounds have melted away from her and she is now just skin and bones. So helping her stabilize and hopefully reverse the weight loss is a priority.”

Williams and fellow astronaut Barry Wilmore completed their pre-mission medical exam before spaceflight and were only scheduled to stay on the ISS for eight days.

But when their Boeing Starliner experienced technical problems, they were stranded in space.

A SpaceX Crew Dragon capsule will take her home – but she's not scheduled to return to Earth until February.

You have now been in space for 155 days.

According to the NASA source, the 5-foot-8 Williams began the mission weighing about 140 pounds.

But as the mission dragged on, Williams was unable to keep up with the high-calorie diet astronauts must eat, the source said.

Because of changes in their metabolism, astronauts consume twice as many calories per day as Earthbound humans need.

“They need to consume about 3,500 to 4,000 calories a day to maintain their current weight,” the NASA official said.

“And when you start to fall behind, the weight drops quickly.”

To make matters worse, they also have to exercise for more than two hours a day to maintain their muscle mass and bone density in a zero-G environment, burning even more calories.

An avid runner, Williams became the first person to run a marathon in space in 2007 by running on a treadmill in the Boston Marathon.

To gain weight, Williams may need to eat up to 5,000 calories a day, the source said.

The average woman on Earth needs about 1,600 to 2,400 calories to maintain her weight.

NASA doctors began working with Williams about a month ago to help her pack on the pounds — even before the viral images sparked global concern about her health, the source said.

Multiple NASA studies have found that the effects of space travel are harsher on women. A 2023 study found that female astronauts lose muscle faster than their male counterparts.

But in a statement Thursday, NASA stressed that there was no cause for concern and that they weren't overly concerned about Williams' weight loss.

“All NASA astronauts aboard the International Space Station undergo routine medical examinations,” the statement said.

“They are being monitored by dedicated flight surgeons and are in good health.”

The alarming photo came after a crew of four NASA astronauts returning to Earth on SpaceX's Dragon capsule were hospitalized after 200 days on the ISS.

According to NASA, one of those astronauts was held overnight at Ascension Sacred Heart Pensacola Hospital.

The space agency did not disclose the nature of the medical emergency and the astronaut was released the following day.

Speculation about Williams' health has become the cause of rumors around NASA, the source said.

“I gasped loudly when I saw the last image,” the NASA official said.

“And it's something we talk about, but not something we obsess about. It’s a real concern and everyone takes it seriously.”