I did decide, it was a few things at once. Have had my fourth dc recently and have been left out of shape literally after having physical problems in this pregnancy which haven't been an issue previously. These are still a bit of an issue and I ended up fatter and less fit than usual, still just in my bmi but looking like a bag of jelly!
The preg complications meant I didn't cook as much or do my veg patch/ greenhouse so our diet was generally less good with more oven type meals...felt bad about this as dc usually get a really healthy diet.
My eldest was starting to want to share my coke, no chance but not a justifiable position.
Dh is much fatter than he wants to be and he has been doing much of the shopping, he bought lots of 'treats' and helped me eat them. I felt sad to see how much his diet and habits have been corrupted by my example. Everyone I have ever lived with has put on around three stone! One lodger managed this in about 6 months.
Anyway it was like a perfect storm and I knew I could change the home diet, dh's weight and my long term health and short term post preg related problems if I stopped eating like a teenager. I knew it was irrational to worry about dh getting fatter but not my arteries, stroke risk etc. This pregnancy showed me that I am getting older, that the choices I make now dictate the future. Incidentally my mum is diabetic, sister obese and this worries me. I have been really fit and want to get back there, dh is actually pretty fit and I want to be able to be able to run and cycle with, not behind my growing children.
I only cold turkied the coke, food is still enjoyed and am eating more at meals and healthy snacks. Am seeing my nil consumption of giant bags of crisps and choc as redirection, my wholemeal apple cake made with a sugar light batter mixture is good honest food. Am only eating honest food (that honestly won't kill me) and eating as a family not scoffing shite when they aren't looking.
As someone who would walk miles to get spicy noodles, hot chips or favoured crisps I now won't do this. I have given myself a budget for 'extra food' it is tiny and basically buys me a hot chocolate or two. There is no junk in the house (no banna chips in the fruit and fibre either ahem) because I can't resist it. Suppose cold turkey is easier but the irony is that my diet is still only ordinary, healthy but not extreme. We had a packet of crisps each with post rugby butties last weekend. I bought the exact amount so couldn't steal more! Hmmm easier to control purchase than consumption.
God sorry have waffled awfully, have been thinking about it all today. You can change however you decide to approach it by increments orcbuilding up to your tipping point.