Next to the picture, The Office star wrote: “Just weighed myself. I’m a fat c*** again.
The most-liked jibe referenced streaming service Netflix, where Gervais’s latest stand-up show Humanity is currently available.
Among the famous faces to get in on the act was Downton Abbey star Peter Egan, who played Hugh “Shrimpie” MacClare, Marquess of Flintshire in the ITV period drama.
Striking a more reassuring tone than other users, Egan wrote: “Diet until you can navel gaze with ease.
“Or don’t worry about it. Have a chilled Burgundy with a wonderful vegan salad followed by another few glasses. Bliss before belly!!”
Impressionist and voice actor Darren Altman, who appeared on Britain’s Got Talent in 2016, was less sympathetic.
Replying to Gervais’s tweet, Altman wrote: “There’s a rumour going round that the other day you fell over and cut your leg. Gravy poured out!”
Gervais told former Daily Show host Jon Stewart in an interview on the US programme in 2014: “I worked out and I lost a little bit of weight but I’m basically a fat guy at heart and it’s killing me. Trying to keep fit is literally killing me.
“I don’t want to give anything up so I still eat pizza and I get drunk every night and then I have to go for a run in the morning, like Rocky, and it kills me.”