But world record-holder Jesse 'Food Coma' Freeman is devouring the critics.
The self-confessed gym junkie eats lean and clean when he's not smashing down burgers, doughnuts and fries.
"At the end of the day, it's just like being an athlete," Freeman said.
"We plan and train so we can do this without destroying our stomachs and oesophagus, or putting on a tonne of fat.
"This is a long-term thing, and we work hard to make sure it's possible."
Freeman has been planning his next challenge for the past several months, as he prepares to consume 40,000 calories in one day.
"Slowly but surely, I've been losing four kilos of body fat so that my body is ready to take in those nutrients, and so that I don't gain a lot of weight," Freeman said.
"It's just about planning for what you know is coming.
"There's the water retention from all the carbs and salt, there's obviously the calories.
"But of that 40,000 calories, not a lot of it will be digested - my body will probably push it out."
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This article originally appeared on 7News