"I have some clients who we send a chef five days a week. Sometimes seven days a week. It is footballers who really struggle to get vegetables, different greens and the right carbs. Basically, they need telling what to eat and when to eat. Some of them just don't have a clue."
It is fast becoming the norm for top-level athletes to hire a personal chef. Tottenham Hotspur striker Harry Kane revealed in October that his private cook had been one of the keys to his goalscoring success this year, explaining how he had been "blown away" to learn about the importance of eating the right foods at the right times. Manchester City's Kevin De Bruyne and Ilkay Gundogan employ a Michelin-star trained chef, while Manchester United's Paul Pogba is reported to have flown a private cook into the country from Italy.
"It has really grown in the last few years," says Yuda Galis, the founder of London-based personal chef services company Galor. "It is mainly Premier League footballers, although we do have others, like boxers, runners and dancers."
The preferred choice, Galis says, is for the chef to work full-time for the sportsman's family, to learn their dietary requirements and prepare the food in the client's home.
As a rule it costs between £300 ($570) and £500 ($950) per day. That does not include the price of the food. If the role is full-time, Harper says, a separate rate will be negotiated.
Jonjo Shelvey, the Newcastle United midfielder, advertised for his own personal chef in 2015. The annual salary on offer was £65,000 ($123,700), which Harper and Galis say is roughly the standard pay for a permanent role.
The menu never deviates too far from what the club expects the player to be eating. There is, though, one clear exception. Harper says: "They are so good throughout the year that I think some of them really look forward to the Christmas dinner."