But what was hyped as a big announcement turned out to be just a publicity stunt to promote her new vegan meal delivery service, The 22-Day Revolution.
The 33-year-old is now facing a major backlash, with fans spamming her Instagram account with emojis of French fries, burgers, drumsticks and donuts.
The Bootylicious singer, who released her fifth solo album with no warning straight to iTunes in 2013, was also criticised on twitter.
"Beyonce dropped a whole album and collection of videos like a thief in the night but wants to make an announcement about her diet?" Byrd tweeted.
Other members of the Beyhive - the adopted name of the singer's loyal fanbase - were similarly unimpressed.
"Beyonce did not wake us up early on a Monday to tell us we need to eat more rabbit food," V tweeted.
"How is Beyonce going to tell me to be a vegan when her and Nicki was feeding each other burgers in the Feelin Myself music video?" Benadryl tweeted.
During the TV interview Beyonce insisted her weight loss was thanks to a new meal plan devised by her trainer Marco Borges.
"I'm not naturally the thinnest, I have curves, I'm proud of my curves, and I have struggled from a young age with diets," she said.
"(But after adopting a plant-based diet), I felt like my skin was really firm. A lot tighter than when I deprived myself of food and got the weight off fast. And the weight stayed off."
- AAP
