Tom Watson's 50th birthday was both a high point and a low point in his life.
He'd celebrated in style at a party in London with his family and friends, enjoying a major blowout that saw him belt out a karaoke duet of Teenage Kicks with one of his musical heroes, Feargal Sharkey.
But the morning after, nursing the worst hangover of his life, he found himself staring at one of his birthday cards.
"It said '50 and fab', and all I could think of was '50 and fat'," he says. "I knew then that I had to change my life completely."
Fast forward two-and-a-bit years and he has done exactly that, slimming down to 14 stone and quitting as the MP for West Bromwich East and as Labour deputy leader.
By the end of next month he will have vacated his London flat, having moved back home near to where he grew up in Wyre Forest.
He's training to be a gym instructor, is in a happy relationship and spends a chunk of his newly found free time with his kids and looking after elderly family members – a breath of fresh air after the last few years of fighting his corner against Labour's hard-left.
He's also written a book, Downsizing, an account of how he lost eight stone and reversed his type 2 diabetes.
Buying a set of scales
It was 2017 when he decided things had to change. "I was reading a biography of my Labour hero John Smith, who died aged 55, and I thought, I'm heavier than he was – and I'm definitely more stressed than he was because I was surrounded by a whole load of trolling lunatics throwing bricks at me," he recalls.
For Mr Watson, 'day one' was when he finally plucked up the courage to buy a set of scales, reacting with a mixture of "horror and relief" when he saw that he was 22 stone.
"I knew that from then on in that would be the heaviest I would be," he says. "I knew I would change it and I would never allow myself to get to that weight again.”
WATCH: Tom Watson on 'inspirational' Blind Dave
We're sitting in Kimmy Loves Cake in Bewdley, where Mr Watson sticks to black coffee and avoids the scrumptious-looking range of goodies on display at the front of the shop.
He’s arrived on an electric bike, his preferred mode of transport these days, and is preparing for a 25-mile cycle ride and his first organised 10km run in the coming months. He is doing both events alongside Blind Dave Heeley, a “huge influence” who Mr Watson says finally got him into fitness after years of trying.
He’s come a long way from the baby steps he took back in 2017, when cutting out refined sugar became the first major step of his new regime.
It followed 25 years worth of false dawns involving what he calls "pretty crazy fat diets", which he often embarked upon with the late former Express & Star reporter Dave Lawley.
"I'm a sugar addict who was getting sugar cravings every three hours," Mr Watson says, recalling how his day would sometimes start with him polishing off cold takeaway curry or pizza from the night before.
"I had been on a 30-year cycle of constantly having to deal with a sugar low, which in my mind meant feeding my sugar addiction at regular intervals until I went to bed at night."
While researching Downsizing he says he realised the extent of his problem, after asking friends and family if they had any interesting anecdotes about eating food with him.
He wasn't expecting much of a response, but says his inbox went into meltdown.
"One of them was about me sitting in a cafe working away on my laptop, and unconsciously I was leaning over onto the next table and eating some leftover rainbow cake,” he tells me.
"Such was my need for sugar, I did not even realise I was doing it.
"It was all part of the problem. I had to change how I slept, the hours of the day that I worked – I was working seven days a week – and after years of denial it was a case of pressing the 'on' switch in my head and beginning to address every part of my life that needed to change."
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At the same time he was ditching sugar, he started regular exercise. His first target was to take 5,000 steps a day – no easy feat at the time when the 2,500 paces from Westminster to his flat would leave him feeling "severely depleted".
The next stage was to walk up every set of stairs he encountered, which he found "a real struggle" when he moved to a new office that was 64 steps up.
He said: "For about two months, I'd get to the top of the stairs and open the office door, and my opening line would be: "Those 'effing steps have nearly killed me again."
It took him a while to be able to jog even a short distance, but after losing seven stone in 12 months, running and cycling started to become part of his routine.
Black Country diabetes problem
To illustrate the point, he tells me that he started the New Year with a seven km run on the Southbank, having been the first person on there after the security barriers had been lifted from the previous night's celebrations.
He has also successfully reversed his diabetes.
"The Black Country, and Sandwell in particular, has a real problem with type-2 diabetes," Mr Watson said. "There are many people who think that once they are diagnosed with it, there is nothing they can do, but it's not true.
"If you change your nutrition and lead a more active life, you can change your condition. I didn't know that when I was first diagnosed [in 2013]. It was a crushing blow and I was in denial over it for years.
"Of 3.4 million type-2 diabetics in this country, around two million can easily reverse their condition."
He describes his efforts to lose weight as "a private battle" which he kept from other people because he didn’t want them to see him fail.
"I also didn't want people interfering," he added.
"I was only doing it to live for my kids and there was nothing anyone could help me. I had to do it myself."
He said keeping his weight down to its current level remains a real challenge, but one which is helped by mindfulness and a conviction to stay healthy.
It has also become easier since he stepped away from the political maelstrom of the Labour Party.
His connection to politics – which started in 1974 when he collected numbers for Harold Wilson at Franche First School in Kidderminster – would become an all consuming obsession that would eventually put a strain on his mental health.
“The changes I made actually helped me deal with a time in my day job when my fight or flight responses were triggered 20 times a day,” he says.
“When I think about the year I had in politics, when all those crazy Momentum people were attacking me... I never let them get to me, and I put that all down to the changes in my lifestyle.”
It really was quite the year for Mr Watson, to borrow a phrase from Jeremy Corbyn. Already a figurehead for moderate Labour MPs, he became the key player in questioning the leadership, particularly over its response to anti-Semitism claims. He fought for Labour to take a stance on Brexit and become “the party of Remain”, and also saw off a botched attempt to scrap his position at the start of September’s conference in Brighton.
"I just laughed at that,” he says, shaking his head as he recalls the Momentum-led coup which occurred at a meeting he was told he did not need to attend.
"It was so deceitful and so politically inept. It destroyed the conference, blew up in Jeremy's face, and meant we had a three day row about a position that no one really cares about.
"The irony for me was that there was pre-election talk in the air, and I felt very strongly that the conference should have been Jeremy's platform to talk to the nation about what Labour would do if it was in government.
"I was intending to have a very low key conference, but then I got off the train and there were 20 camera crews and they followed me around all week.
"I became the story."
He says he has “absolutely no regrets” about his decision to quit, which was made just hours before it was announced after weeks of soul searching.
His personal life had changed for the better and writing the book had been a “cathartic experience”. There had been some threats made against him.
"I looked at it all, as well as the fact that I had expended a lot of political capital trying to hold the party together during a very difficult few years,” he says.
“I decided that if I stayed there was very little else I could do. The reality is, I had run out of road and it was time to take a different path.
“I knew the decision would shock people, but I hope with hindsight that colleagues will reflect that I did the right thing for me and my family.
“If I thought I could have made a difference, I would have stayed. I had a good innings, I did some good, but it is now time to do something else.
“No one is indispensable in politics, and the politicians who fail the most are the ones who don't realise that."
He said he was determined to leave on a positive note, “without rancour and bitterness”, and watched the carnage unfold from afar.
"It was pretty bad, and I think even if Theresa May had still been leader, Labour still would have lost,” Mr Watson said.
He says the party’s lack of a clear position on Brexit was a key failing, but said it was wrong to try and pin the defeat on Mr Corbyn, insisting MPs and party members should also take their share of the blame.
Labour’s “over-ambitious” manifesto failed to convince voters, he added.
Mr Watson has yet to decide who to back in the Labour leadership contest, although he has already made clear his opposition to Rebecca Long Bailey.
“I want to see the candidates show they understand why Labour lost… and show how they will win back the trust of voters in places like the Black Country,” he said.
"The membership has got to decide if they want a leader who is politically pure in an ideological sense, or is prepared to make the compromises required to be electorally successful."
For now he’s concentrating on his book - already an Amazon best seller – which he insists is not about him "telling people what to do".
"I did too much of that in my day job as an MP,” he says. “My only advice is that there is only one person you have to defeat in this journey, and that's yourself.
"You have to quell the doubt in your own mind."