England coach Eddie Jones wrote a letter to all his leading players, advising them to keep a tight control on their weight during the off season.
Such a request was particularly poignant for loosehead prop Mako Vunipola, and his younger brother Billy, who have regularly faced issues controlling their bulk. The pair have to be particularly careful during their trips to Tonga to visit their family.
And the letter from the head coach included a few personalised individual instructions to particular squad members, with Vunipola being warned 'watch what you eat.'
The older Vunipola told a press conference his weight had increased by half-a-stone, but admitted he was not too unhappy about this.
Speaking ahead of this autumn's series against South Africa, which starts on Saturday, November 12, he said: "I was expecting worse so that weight was all right!
"I got a letter through saying I'm in contention and I'm happy to be in contention.
"Eddie likes to keep us on our toes and everyone got the letter reminding them of what they need to do.
"My interesting bit was don't eat too much. To lose some weight."
Vunipola also explained he is having to undertake judo sessions in a bid to improve his breakdown skills.
The training will take place under the watchful eyes of national coaches JP Bell and Katie Howie, and the 25-year-old claims he is dreading it.
He said: "The last time I did judo I nearly passed out! I did it at an under-18s camp. That was my first and only experience of it.
"We had to roll backwards and forwards all the time. I was heavier back in the day, so by the seventh or eighth roll I nearly passed out so they made me stop. Judo's not my game!
"It will be good for all that tackling work around the ball and for grappling at breakdown."