The most bizarre diets in football: Chelsea's condiment ban, Erling Haaland's love of cow heart and liver, and Cristiano Ronaldo's mini-meal routine... but which former Arsenal star ate KFC before every match?

Many moons ago, there was no concept of nutritionists advising elite-level footballers to eat healthy in aid of their performance on the pitch. Well, times have certainly changed.

Before the 21st Century came along, players lived a simple life when it came to food. A breakfast could be a simple bowl of cereal, and they may even have a burger for lunch. They didn't see eating as a science like they do now.

The way of the modern game means footballers need special diets to ensure they maintain the right shape to compete at the top level all year around.

Nutrition in the current era of the game can be likened to how a racing car needs top-of-the-range fuel to perform at a breakneck speed. Clubs and players create a formula to keep them energised.

Enzo Maresca's reign at Chelsea has already brought a new nutrition plan to Stamford Bridge, but players don't always leave it to the professionals when it comes to their diet.

While the majority of players will stick to the routine given to them by the specialists, some have crazy diet habits that they feel get them in the right shape to perform at the top of their game.

Here at Mail Sport, we take a look at some of football's maddest diets, imposed by both dieticians and the players themselves.

Chelsea's new food bans

With a new manager, comes new staff, and new beginnings. Enzo Maresca was appointed by the Blues last Monday on a five-year deal and in his first week there have already been some changes.

Players are currently either on holiday, or with their international sides, but when the time comes for them to return to Cobham in preparation for the new season, they could be in for a surprise - and not a Kinder one.

Moving to west London alongside Maresca will be Marcos Alvarez, the new fitness coach. When it comes to nutrition, the Spaniard can be extremely demanding, insisting on a strict diet plan for his players.

Alvarez's methods include banning various sauces, cake, salt and pepper, and even fruit juice. The hardest one to stomach for the players is perhaps that the coach does not allow fried eggs.

While his nutrition strategy can only be described as cruel to the taste buds, his methods have a track record of bringing results. They worked wonders at Leicester City last season as the Foxes achieved promotion to the Premier League.

However, while his formula may work, players are not always receptive to its uncompromising nature. While working at Tottenham under Juande Ramos, certain members of the squad did not take to the system and tried to sneak McDonald's into a pre-season camp with the help of security.

Erling Haaland's 6,000-calorie-per-day diet

Sometimes the advice of a club dietician is not enough for the sports top stars, and Erling Haaland has found his own way to fuel his healthy habit of chewing up the goalscoring record books.

It takes more than just your usual grub to oil the machine in front of goal that is Haaland. The Norweigan attacker is known to eat Cow liver, and on top of that, he devours the heart too. Not something you would see every day on a regular pub menu.

Such unusual dietary habits are part of the City man's 6,000 calorie-per-day diet. Yes, you read that right. When you consume such an unfathomable amount of calories, it can't all be clean eating, though.

And it's not. Haaland sticks to his meat-loving habits, and on occasion switches out animal organs for a greasy kebab. In his documentary about his move to Manchester, Haaland: The Big Decision, the 23-year-old revealed his deep affection for kebabs, stating simply, 'I love it'.

Now into the fifth paragraph, you have probably worked out that Haaland is a fan of meat, and there is more to it. The striker who is fond of his nickname 'The Terminantor', also has an appetite for steak, lobsters, duck, and oysters.

Despite all the different meat he demolishes on a day-to-day basis, there is one dietary requirement that is key to Haaland's success above all else... Milk. Yes, Haaland loves milk, he once described it as his 'magic potion'.

Cristiano Ronaldo's six mini meals per day

When you look at Cristiano Ronaldo, you just know his diet must be special, and that is one way of putting it. The footballing legend doesn't just eat three meals a day, he eats six.

It seems like a lot of food, and it is, but not all is what it appears to be. The six dishes in question are all miniature, Ronaldo does not eat a full-sized meal every single time.

As you would expect with the forward, each spread is catered to a specific diet for him by a nutritionist. Every dish is packed with the protein and nutrients needed to be at the top of the sport.

Unlike Haaland, Ronaldo mainly avoids red meats and sticks to Chicken as it has the highest protein content while remaining low in fat.

However, his main go-to is actually fish, and it has to be fresh, of course. We aren't talking battered fish from the local chip shop, Ronaldo eats sea bass, swordfish, and sea bream.

As well as eating his vegetables to make up a healthy balanced diet, the former Manchester United and Real Madrid attacker avoids alcohol at all costs. Not to mention, he is also not a fan of fizzy drinks.

Jamie Vardy and his love of caffeine

I'm pretty sure Jamie Vardy would struggle in the Ronaldo household, the fizzy drinks rule would most certainly be broken. The Leicester City striker is renowned for his love of energy drinks, specifically Red Bull.

Caffeine is the key to Vardy's success it seems, because as well as getting his fix from the Austrian brand's famous can of energy, he is also a huge fan of coffee.

'I wake up in the morning and then [have a] Red Bull,' he said to Sky Sports in 2022. 'Literally, I get out of bed, get the kids up and downstairs, get their breakfast sorted, and then I'm straight into the Red Bull.

'After that, we meet at the stadium for pre-match and while I'm getting changed I'll have a coffee - it's better than taking ProPlus. Red Bull, coffee, and then when we get over to the pre-match lounge, I'll have my cheese and ham omelette with another can of Red Bull.'

It's clear to see that Vardy does not follow the usual diet of a modern-day elite footballer, but his success in the sport proves that not every machine needs the same oil. Remember, some cars are unleaded petrol, some are diesel, and others are electric.

In the 2015-16 season, the campaign that saw Leicester miraculously take home the Premier League title, the former England international had a ritual that I don't imagine many top players carry out.

He used to drink port wine, disguised in a Lucozade bottle, before every matchday. It worked because his goalscoring was unrelenting that season.

Antonio Conte's ketchup ban

For any ketchup-loving professional footballers out there, you have to hope Antonio Conte doesn't walk through the door as your boss someday. Why? Because he doesn't allow his players to use the condiment.

The Italian manager has recently taken over at Napoli, and the squad should brace themselves for a Chelsea-style exodus of foods. Just like the new fitness coach at the Blues, has banned fast food as well as sauces.

Conte does not mess about when it comes to health and nutrition, he likes to keep his players on the straight and arrow to ensure success. Speaking upon his arrival at Tottenham in 2021, he revealed why strict dietary requirements are put in place at his clubs.

He said: 'At every one of the clubs that I trained I had a nutritionist and these aspects are important because you have to stay in the right weight and to do that you have to have the good fat and the good muscle.

'This is a part of our work now and the player's work - to be professional. To be professional means you have to take care of your body. If you do this, you recover well and you are at less risk of injury for sure. You are also ready to face the training if sometimes the training is hard.'

If any Napoli players try to sneak fast food under Conte's nose, they will regret it. He has previously stated that he always knows when players are trying to break dietary rules.

I wouldn't want to get on the wrong side of Conte, and I assume neither will his new players. Although, the thought of having to avoid ketchup for your profession is distressing. Luckily for condiment manufacturer, Heinz, they are not a sponsor of Napoli.

Alex Song 

One player that probably would have put himself on the transfer list if he played for Cont, is Alex Song. The former Arsenal midfielder loved a bit of fast food, so much so that he had a Kentucky Fried Chicken (KFC) meal before every match.

It's hard to believe that Arsene Wenger - Song's manager at the Gunners - would have allowed the midfielder to tuck into such food on a regular basis.

After arriving in north London in 1996, Wenger revolutionised nutrition in football. When he walked through the door at Highbury, the drinking culture was rife throughout the squad.

However, his approach to dieting and fitness changed the game, well, for the majority. His methods obviously didn't have an effect on Song and his love of KFC.

Song's former Arsenal teammate once recalled how the midfielder wouldn't hide his love for the fast food chain. He said: 'There was Song, who used to go to KFC before every home game. On the bus to the team hotel the night before the game, he would be eating chicken nuggets.'

Being fuelled by KFC seemed to work for Song, as he earned himself a move to Barcelona after six years playing in the red and white of the Gunners.

He only retired from professional football last November at the age of 36, and now he can eat as much fast food as he wants without the worry of being caught by the nutrition-mad Wenger.