Having two younger brothers, I learned to eat really quickly, because the first to clear their plate got first dibs on more. I was always in such a rush. Savouring the tastes and textures on my tongue is something I only got into 18 months ago.

The slow cooker flips on at 3am to do my porridge and flips off at 6am. My alarm goes off at 6.15 and, to feel sane, I press snooze once. The first thing I do when up is squeeze half a lemon into a glass of water, then do 10 minutes meditation, then the porridge and I am good to go.

I only started drinking coffee after I moved to London and people were saying “Let’s meet for coffee” and I’d have to reply, “I’m all right – I don’t need one right now.” I started on lattes with pumps of caramel syrup – each pump alone is 20 calories, three is 60 - and I’ve weaned myself down to filter blacks. A whole-milk latte is 223 calories, a skinny 131, but a straight filter only five.

My earliest memories are of licking my auntie’s cake spoon. I was properly baking with her at five but the first thing I learned to make alone, at eight, was broccoli bake. On weekends, if I wasn’t diving, I’d say, “I’ll make dinner for everyone and get really chuffed with myself.” But I wasn’t trusted with chicken again after putting a whole chicken in a frying pan and thinking it was cooked once brown on the outside.

People would buy me Jamie Oliver books as presents. Then when I was 11 or 12 they didn’t know which cook books to get any more, so they’d give me kitchen gadgets – a soup-maker, pastry-maker, ice-cream maker, popcorn maker, a candy-floss maker, an omelette maker, quesadilla maker, tortilla warmer… Practically everything you see in shops I’ve got. Nowadays I’m obsessed by mugs and anything else with union jacks on them. My manager’s just brought me a union jack bottle of champagne.

I’ve been diving since seven and competitively since nine. I started going to World Class Start camps where there was always an evening presentation by a nutritionist. When you’re nine and being told, “Your plate should look like this picture”, you just think “Yeah, whatever.”

Arriving at my first camp in China, in 2006, I was thinking, “Fantastic, the food will taste like takeaways for 10 days!” But we stayed in a school where they served chicken claws and all sorts. But I only had the rice and cabbage and wished I’d packed Pot Noodles. Maybe to beat the Chinese divers you have to eat like them.

I won the 2009 sports personality of the year at the Plymouth Herald awards and Dad, right there and then, poured his pint of beer into my glass trophy, went “Yeeeeeaah!” and drank it. There were so many things he did which made me go, “Dad, stop it – it’s annoying, so embarrassing.”For some reason he always found pleasure in making me blush. But looking back since he died, I think, “Yeah, I kind of understand why he did that and it was quite a cool thing.”

Until I was 17 I took cod liver supplements, because I wouldn’t go near fish. I’d always want sausage rather than fish. It wasn’t that I didn’t like fish, just that I’d say I didn’t like fish. Probably because Dad didn’t.

I only occasionally drink alcohol at the moment. I stopped for two years before each Olympics, wanting to be completely in the zone, then afterwards I’d run in the food hall – the size of five football pitches – for ice creams, then start drinking again. After the 2012 Olympics especially I got the blues after a massive high. I took 10 days off and in those 10 days got an idea of what it’s like to be 18 and go out and have fun. It’s really important to set short term goals so that I’ll be in the best shape possible for 2020. So I think of a glass of wine as a doughnut.

I’d like to think that chlorine doesn’t affect my taste buds. I’ve been in chlorine all my life.

Tom’s Daily Plan (HQ, £16.99) is out now. Click here to order a copy from Guardian Bookshop