The 30-year-old has, over the course of his career, intermittently thrown up on the pitch during matches.
That had led to speculation that the five-time Ballon d’Or winner might struggle with weight of expectation or stress.
Barcelona agree deal for Bayern Munich midfielder Vidal
03/08/2018 AT 21:29
However, in an interview with La Cornisa TV Messi revealed that a simple change to his diet had solved the issue.
"I ate badly for many years: chocolates, fizzy drinks, and everything," said Messi.
That is what made me throw up during games. Now I look after myself better. I eat fish, meat, salads. Everything is organised and taken care of.
The Barcelona star also dismissed the idea that his on-field vomiting was linked to stress.

Barcelona's supporters hold a giant banner depicting Barcelona's Argentinian forward Lionel Messi during the UEFA Champions League round of sixteen second leg football match between FC Barcelona and Chelsea FC at the Camp Nou stadium in Barcelona on March

Image credit: Getty Images

"I've learned to live the way I do, to be myself because at the end of the day it's easier to do it that way," he added.
"I don't think too much about how I have to act because of constantly being watched.
“I'm aware that whenever I speak there are many people that listen, that there are repercussions. I always try to think about what I say in order not to generate controversies."
Messi is currently enjoying another stellar season, having hit 25 goals in the league for a ninth consecutive season last weekend, and he will lead Argentina at the 2018 World Cup.
Watch his interview below:
Griezmann signs new deal with Atletico after rejecting Barca
18/06/2018 AT 21:49
Real confirm Rodrygo transfer for 2019
15/06/2018 AT 16:12