Lionel Messi and Luis Suárez have a taste for it and Cristiano Ronaldo often digs into a slice after games. Claudio Ranieri used it as a motivation tool during Leicester City’s title win, bringing his squad to a local Italian restaurant following their first clean sheet of the season. But their success is not sufficient evidence for Pep Guardiola, because pizza will not pass the mouths of any Manchester City players this season.

As revealed by Gaël Clichy on Tuesday, the new manager has banned his side from chomping on the Italian classic and has told his players if they are overweight they will not be allowed to train with the first team.

It may seem harsh and deliveries to dressing rooms immediately after games are common across the country – just ask one former Arsenal player and Sir Alex Ferguson – but there is an obvious reason behind Guardiola’s stringent policy.

The nutritional benefit for finely-tuned athletes is minimal – a replacement for lost carbohydrates but little else – and with the stakes so high, every gain no matter how minimal is sought. The belief that pizza is a good recovery meal for players immediately after a match exists but there is little evidence to prove it.

“What players choose to eat after a match is never particularly healthy but the choices are especially important immediately after a match,” says Caroline Farrell, Fulham’s nutritionist. “You don’t get what’s needed from pizza. Players’ glycogen stores are used up, they need more protein and pizza is high in saturated fat and salt. Ideally what they should be having is fruit and veg, lean protein, complex carbohydrates.”

Yet a post-match delivery is often an act of convenience – especially at away games where access to a kitchen to prepare the ideal meal is unrealistic. Even then it is important to choose the right toppings – pepperoni and other processed meats are frowned on and the amount of cheese will also be monitored.

“Sometimes clubs will choose to give them pizza out of convenience,” Farrell says. “Then it’s a case of choosing the right toppings. Single rather than double cheese, using chicken instead of processed meats that are higher in saturated fat content.”

The ideal meal would be fresh fish high in Omega-3s, like organic salmon, with complex carbohydrates such as brown basmati rice and a selection of vegetables, or brown pasta with chicken, tomato sauce and salad.

Other foods and condiments are also banned at clubs. Farrell recalls revamping Watford’s canteen, having been hired by the club during Gianfranco Zola’s time as manager, and making sure ketchup and margarine were thrown out. She also made sure all ingredients were locally sourced, organic and seasonal.

It is not solely about players’ weight and fat percentages. Their diet can also impact on injuries and their sleep patterns. “I work with players on things like supporting their sleep, making sure they eat the right food before bed,” Farrell says. “Players with injuries should be on anti-inflammatory diets. It gets a lot more complex, every bit counts. You don’t want a player with digestive issues getting ill all the time.”

Players cannot be watched constantly and it is inevitable a sweet tooth will get the better of some. “You don’t need to offer a treat because they will often have a sweet tooth and indulge anyway,” Farrell adds. “I always say to be careful during the season. It’s really easy for them to go over their body fat and that has obvious effects on their performance.”

While nutrition and sports science are relatively new, their importance is only going to grow. Players are becoming more aware and scepticism is wearing away. For Farrell it is important to find a way to motivate players and make them realise the healthier their diet the better their body is equipped come matchday. “At the beginning of every season I talk to the squad as a group and on an individual basis to try to motivate them. Every one of them has a strong personal goal and if they think food will help them – if you tap into what motivates them, once they know they’re eating right foods it can only be good for the team.”

It may taste good but is it better than the sweetness of three points at the weekend? Ultimately that is the point Guardiola is trying to drive home.

Pizza’s place in football

24 October 2004

Arsenal’s Cesc Fàbregas achieves infamy in Old Trafford’s so-called Battle of the Buffet/Pizzagate – allegedly throwing the slice that forces Sir Alex Ferguson to change his shirt before giving a post-match interview. “He had great technique,” Martin Keown said years later. “He threw it like a Frisbee.”

25 September 2014

Leaked post-match meal preferences show Barcelona’s finest base their recovery not on sports science but on topping choice. Lionel Messi goes for plain cheese pizza; Sergio Busquets for York ham pizza; Jordi Alba for Hawaiian plus a turkey roll. Goalkeeper Marc-André ter Stegen lets the side down by requesting “sushi and a chocolate spread sandwich”.

24 October 2014

Claudio Ranieri’s fifth-placed Leicester finally keep a clean sheet – so he takes them out for a pizza party. “They deserve this pizza; today we will eat,” he says. “Football is like pizza. The most important ingredient is team spirit. Also to sprinkle a little luck is important, like salt. But the fans are the tomato. Without the tomato, it’s no pizza.”