A Russian fitness trainer died in his sleep after forcing himself to binge on fast food in a risky bid to prove the effectiveness of his weight-loss programme.

Tragic Dmitry Nuyanzin, a well-known coach and influencer from Orenburg, spent weeks gorging on junk food as part of a ‘marathon’ challenge he hoped would inspire his clients to shed weight alongside him.

The 30-year-old-who reportedly consumed up to 10,000 kilocalories a day-planned to gain at least 25kg before demonstrating how quickly he could slim back down.

But the trainer’s heart failed as he slept, according to Ostorozhno Novosti channel.

He had cancelled training sessions a day earlier, telling friends he felt unwell and intended to see a doctor.

Three days later, he was laid to rest in Orenburg.

Nuyanzin documented his dramatic weight gain online, showing his ‘daily diet’ to his thousands of followers on a Russian social media platform.

This included pastries and cake for breakfast; dumplings smothered in mayonnaise for lunch; and a burger with two small pizzas for dinner.

He also admitted snacking on crisps throughout the day.

A Russian fitness trainer died in his sleep after forcing himself to binge on fast food in a risky bid to prove the effectiveness of his weight-loss programme

A Russian fitness trainer died in his sleep after forcing himself to binge on fast food in a risky bid to prove the effectiveness of his weight-loss programme

Tragic Dmitry Nuyanzin, a well-known coach and influencer from Orenburg, spent weeks gorging on junk food as part of a 'marathon' challenge he hoped would inspire his clients to shed weight alongside him

Tragic Dmitry Nuyanzin, a well-known coach and influencer from Orenburg, spent weeks gorging on junk food as part of a ‘marathon’ challenge he hoped would inspire his clients to shed weight alongside him

The 30-year-old-who reportedly consumed up to 10,000 kilocalories a day-planned to gain at least 25kg before demonstrating how quickly he could slim back down

The 30-year-old-who reportedly consumed up to 10,000 kilocalories a day-planned to gain at least 25kg before demonstrating how quickly he could slim back down

By 18 November, he revealed he had reached 105kg, gaining at least 13kg in a month.

His challenge rules promised that anyone weighing over 100kg who lost 10% of their bodyweight by New Year would win 10,000 rubles [£100], paid directly by him.

‘I am currently gaining weight for my weight-loss course, and this is my 10,000-calorie diet,’ he told followers.

‘For breakfast, I have a plate of pastries and half a cake.

‘For lunch, I usually eat 800 grams of dumplings with mayonnaise.

‘During the day, I may snack on crisps, and for dinner, I have a burger and two small pizzas, either at a café or delivered.’

The trainer was a graduate of the Orenburg Olympic Reserve School and the National Fitness University in St Petersburg, and had worked as a personal coach to elite Russians for a decade.

Friends described him as ‘bright’, ‘positive’ and ‘an amazing person’, with tributes flooding Russian social media.

But the trainer's heart failed as he slept, according to Ostorozhno Novosti channel. He had cancelled training sessions a day earlier, telling friends he felt unwell and intended to see a doctor

But the trainer’s heart failed as he slept, according to Ostorozhno Novosti channel. He had cancelled training sessions a day earlier, telling friends he felt unwell and intended to see a doctor

Three days later, he was laid to rest in Orenburg. Nuyanzin documented his dramatic weight gain online, showing his 'daily diet' to his thousands of followers on a Russian social media platform

Three days later, he was laid to rest in Orenburg. Nuyanzin documented his dramatic weight gain online, showing his ‘daily diet’ to his thousands of followers on a Russian social media platform

This included pastries and cake for breakfast; dumplings smothered in mayonnaise for lunch; and a burger with two small pizzas for dinner

This included pastries and cake for breakfast; dumplings smothered in mayonnaise for lunch; and a burger with two small pizzas for dinner

One wrote: ‘Dima [Dmitry], it’s so sad that you left so early… such an incredible person.’

Another said: ‘I’m in total shock. Why does God take the best people?’

His death came just months after another high-profile fitness figure, Belarusian bodybuilder Ilya ‘Golem’ Yefimchuk, 36, died of cardiac arrest in September.

Yefimchuk reportedly consumed 16,500 kilocalories daily to maintain his 158kg frame.

Nuyanzin, who was married and had no children, previously served an eight-month sentence in a grim Russian penal colony for drug possession in 2022, before returning to his coaching career.

His heart ‘stopped beating in his sleep’, said friends.