Most of us can only imagine what it's like being an astronaut - safe to say that it's very different from the space camp you got sent to when you were younger.
More than just the emotional toll of flying hundreds of miles above your loved ones, zooming to the cosmos is physically exhausting as well.
Concerns were recently sparked when images of stranded astronauts Barry "Butch" Wilmore and Sunita "Suni" Williams went viral.
Advert
Wilmore and Williams were supposed to go on an eight-day mission back in June, but due to a fault with their Boeing Starliner, they're now 'trapped' aboard the International Space Station until February 2025.
While the pair have admitted to facing 'tough times' because of their unexpectedly extended stay, they seem in high spirits.
Williams has now clapped back at concerns about her appearance and apparent weight loss, telling viewers in a NASA live video that she's put on muscle.
Advert
She assured those watching: "There are some rumors around, outside there, that I’m losing weight and stuff. No, I’m actually right at the same amount.”
Williams said it feels like the opposite and added: "My thighs are a little bit bigger, my butt is a little bit bigger. We do a lot of squats."
She maintains that her change in appearance was due to a 'fluid shift': "I think things shift around quite a bit, you probably heard of a fluid shift. Folks in space you know, their heads look a little bit bigger because the fluid evens out along the body."
It's true that during spaceflights, blood and fluid shifts from the lower parts of your body to the upper areas, which can sometimes cause the appearance of a puffy face and thinner legs.
This comes after pulmonologist Dr Vinay Gupta expressed his concerns and suggested Williams, in particular, looked like she was facing a 'significant' calorie deficit: "What you're seeing there in that picture is somebody that I think is experiencing the natural stresses of living at a very high altitude, even in a pressurized cabin, for extended periods.
Advert
"Her cheeks appear a bit sunken - and usually it happens when you've had sort of total body weight loss. I think what I can discern by her face and her cheeks being sunken in is that [she] has probably been at a significant [calorie] deficit for a while."
As for why we might be noticing a difference in Williams when compared to Wilmore, a 2014 NASA study found that women tend to lose more blood plasma volume when compared to their male counterparts during a spaceflight. This can lead to a temporary increase in a woman's metabolic rate, which increases calorie burn and weight loss. Still, Williams assures everyone she's fine and has been enjoying a varied diet including Turkish fish stew and olives.
With the faulty Starliner out of action, Wilmore and Williams are hoping to catch a lift back on February's SpaceX Crew-9 in February 2025