Last year it was alleged Prince Harry gave up alcohol out of sympathy for his pregnant wife, Meghan Markle.
But according to a royal insider, the Duchess has decided 2019 should ring in an end to tea and coffee for her husband too.
While friends say the new health kick is showing in the fitter, bright-eyed Prince, according to the Sunday Express, "Considering he's been a pretty brutal drinker since he was a young teenager, it's quite an achievement."
Markle, 37, has also introduced Harry, 34, to yoga and encouraged him to exercise more. His efforts were noticed ahead of his wedding to the American divorcee in May last year.
Friends have also noted Harry's healthier lifestyle has left him "more chilled and relaxed", with a source telling the Express "All [Meghan] did was show him there's another way to live and he's become a huge fan.
"He eats well, doesn't poison his body, exercises, does a bit of yoga and is a lot happier."
Spotted raising a glass of water at a state dinner last October, the royal father-to-be certainly appears a reformed character compared to the antics of his youth.
In 2012 he was photographed in a Las Vegas hotel room after playing "strip billiards" and in 2011 was caught on camera drinking and jumping fully clothed into a swimming pool in Croatia.