Kell Brook is set to fight Errol Spence Jr. for the IBF world welterweight title in Sheffield tomorrow night and has been shedding weight just in time by eating a load of fattening food.

Brook went up a weight to fight Gennady Golovkin last September and has faced an uphill battle to shed the two-and-a-half stone in time.

In the end, the Sheffield man did it by putting himself through a 20-week camp of the ketogenic diet.

The diet includes the likes of cheese, bacon, and butter in coffee, but according to Brook's success, it seems to work.

His nutritionist Greg Marriott spoke of how the diet works: “There are numerous diets out there that people think are fad diets.

“The ketogenic diet works but you have to stick to a process. It’s low carb but your good fats have to be high. People get this wrong — you have to have a certain amount."

So, before you start gorging on pizza in a bid to shift the pounds, read more of Marriott's advice.

“If you have too much protein then ketosis, where your body burns fat for energy, will just stop.

“A lot of people will have fish, meat and not enough fat but then you’re not doing ketosis. You’re wasting your time."

Brook's diet was full of good fats and not a lot of grease. Duck breast with the skin still on next to a side of green veg isn't the same as a large doner kebab.

According to Marriot, Brook did so well on his diet and weight loss programme, that he has been able to eat normally during this fight week - something that few fighters can typically afford, including Brook.

“Kell’s never been able to do that before. The only shape I’ve seen him in like this is before the Shawn Porter fight when he won the world title."

While Brook cut the likes of chocolate and cakes out of his diet, he is ready to dish out a few 'chocolate brownies' to Spence - who is undefeated thus far in his career.

Brook is hoping that his wicked right hand (described as sweet as chocolate by the man) will see him through the fight on Saturday, but knows that it will be difficult to beat Spence even with his home advantage.

Brook also wants to win the fight for Britain after the Manchester bombing.

One of the people who died in the terrorist incident was from Sheffield, and Brook wants to give the city (and the UK) a positive note to hang onto to - much like Manchester United did upon winning the Europa League.

“One of the people who died was from Sheffield so Saturday is about Sheffield coming together for one night, turning everything that happened into a positive really."

Do you think Kell Brook's diet will have set him up well to beat the undefeated Errol Spence Jr? Let us know in the comments.