OK great, thanks to you all.
On afew calorie/exercise sites it states that I am burning around 300-390 cals, I am also pushing a pram with a 5 and 3yo in it and keeping up my speed, but I am not counting that.
I am putting into fitnesspal app that I burn 200cal, so hopefully that will be OK. Sometimes i eat it all, sometimes I don't feel like it, but I don't want to hold weight from not eating what the body needs at minimum.
That said i have 20kg to lose...
But I want this to be a lifestyle change rather than a quick fix, hence the question.