The relentless involvement of betting companies in football has drawn a generation of young men into strongly associating their support for the game with gambling, leading to “dire consequences” for many, a study has found.

The explosion in marketing and sponsorship since the last Labour government deregulated gambling in 2005, combined with the ease of online betting via smartphones, has resulted in the “gamblification” of watching football, according to research conducted by Dr Darragh McGee of the University of Bath.

McGee spent two years working closely with two groups of football supporters aged 18-35 in Bristol and Derry, recording their gambling habits in depth, in a research project funded by the British Academy.

His findings, shared exclusively with the Guardian, include some of the young men telling him they can no longer watch a football match unless they have multiple bets; commonly they have up to 25 accounts with online gambling companies, and their football conversations with mates are all about betting, rather than the game.

Participants said the gambling companies’ marketing is extremely effective, particularly the offers of “free” bets, and that their losses did not feel like real money because they are placed so casually on a phone and no longer involve going to a bookmaker’s shop.

One told McGee the “buzz” of gambling is “up there with sex and drugs and rock’n’roll”, saying: “And I think because of that, gambling is the worst addiction of the lot.”

That participant, a 31-year-old father of two in Derry, ultimately disclosed to McGee he had turned to drug dealing for a period to try to recoup money saved for a family holiday, which he had lost gambling.

The participant told McGee he had 40 accounts with online betting companies and cannot watch matches, except the odd Premier League game, without betting. This includes in-play bets on the number of corners, throw-ins or yellow cards. He said he was “in debt to my eyeballs” on high-interest payday loans taken out to cover gambling losses, and his credit was “blacklisted to the max”.

Gambling promises a route to wealth, social capital and masculine affirmation yet most end up in a cycle of indebtedness Dr Darragh McGee

He said that gambling “took over my life for a while” and he has deep regrets about having neglected his baby daughter, because he would “sit on the laptop, continuous gambling for the day” when looking after her. He told McGee he had lost two friends to suicide, one directly attributed to gambling debts. Derry, like other areas of Northern Ireland, has some of the highest suicide rates in Britain.

As McGee came to know the groups, he found the intensity of the online gambling culture in football has had catastrophic impacts on many of the participants. “Far from being the knowledge-based, risk-free activity it is marketed as, the profound appeal of online sports gambling has had dire consequences for many young men,” McGee has concluded, in research which is complete and due to be published academically next year.

“The study documented the unfolding stories of several young men whose everyday lives are punctuated by deepening social and financial precarity, high-interest payday loans and bank debt, mortgage defaults, family breakdown, and mental health struggles.

“In particular, for young men who find themselves deprived of viable routes to employment opportunities, gambling promises an alternative route to wealth, social capital and masculine affirmation, yet most end up ensnared in a cycle of indebtedness.”

Young men commonly they have up to 25 accounts registered with online gambling companies, the research found. Photograph: John Stillwell/PA

McGee shared his findings after the major online betting companies represented by the Remote Gambling Association announced they would voluntarily stop “whistle-to-whistle” television advertising during the broadcasting of live sport, except for horse racing. That measure was proposed by the Labour party as part of a reform package including a 1% levy – 10 times the current 0.1% levy – to fund research and treatment for gambling addiction.

McGee welcomes the proposed whistle-to-whistle advertising ban as “a step in the right direction” but said: “A generation of young people already view gambling as a normalised part of sport. Turning the tide will require stronger state regulation and a genuine commitment to redistributing a greater slice of the losses incurred by British gamblers to education and treatment for problem gambling. Educating the next generation about the dangers will be key.”

The betting companies have such huge “visibility” via ubiquitous sport sponsorship, marketing and advertising, and have had a free hand for so long, that the voluntary ban is unlikely to limit the amounts being gambled. The participants in his research said that once they were signed up to betting accounts and apps, the constant prompts during matches, and marketing offers, particularly offers of “free” or matched bets, were powerful encouragements to gamble.

A total of £14.4bn was lost by people betting in the UK from April 2017 to March 2018, according to figures produced by the Gambling Commission, an increase from £13.8bn the previous year. Of that total, £5.3bn was lost gambling online, a 12.8% increase on the previous year.

Online betting companies have targeted football in an industrialised way, paying for sponsorship and advertising, including in football-related media – the Guardian accepts such advertising – at a time when revenues from other advertisers are diminishing. This season, nine out of the 20 Premier League clubs have a gambling company as their main shirt sponsor, and as many as 17 out of the 24 Championship clubs. SkyBet sponsors the Football League and its three divisions, and is promoted by Sky during sports TV coverage.

Leeds and Aston Villa are two of five Championship clubs sponsored by the online casino 32 Red, with Derby, Middlesbrough and Preston. Photograph: Craig Milner/News Images/Rex/Shutterstock

Major betting companies based in the UK, offshore and in overseas countries, particularly Asia, also sponsor billboards around pitches, which are prominent during broadcasts. Research by Goldsmiths University last year found gambling logos or branding were on screen for between 71% and 89% of Match of the Day programmes, even though the BBC does not carry actual advertising.

McGee’s work with younger fans has led him to conclude that the marketing has “hooked” a generation into “an accelerated sports culture in which the casual staking of money is an essential accompaniment to watching the game”. He says “a new generation of sports fans view gambling as vital to their enjoyment of sport”.

One of the participants, a 27-year-old living in Derry, told him: “As much as I enjoy it, gambling has ruined sport now, because you can’t watch it without thinking: ‘I should put a fiver on first goal.’ You can’t just enjoy it for what it is. It has completely taken over. All my mates can’t watch it without having a bet any more. It has ruined sport.

“Now, I’m sat there thinking about what I should be betting on, or asking the boys who the smart money’s on tonight. At times, I end up betting against United just to make it interesting! I can’t remember the last time I just watched the game like a real fan, without having a bet on it.”

• In the UK, Samaritans can be contacted on 116 123 or email jo@samaritans.org. In the US, the National Suicide Prevention Lifeline is 1-800-273-8255. In Australia, the crisis support service Lifeline is 13 11 14. Other international suicide helplines can be found at www.befrienders.org.