Thanks guys, it was first thing in the morning before I'd had a drink so I'll test again tonight when I'm fully hydrated :)
In other news, I hoiked up my big girl pants last night and went over to my Mum and Dads. First time they've seen me since I started bootcamp and inevitably, they noticed I've lost a bit. the dreaded "how have you done it? how much have you lost?" conversation sprouted so I bit the bullet and told them.
Mum went MENTAL.
"Your aunty aunty I've never met did atkins for a month and got diabetes, as soon as she ate normally again she gained it all back! dont be stupid, just eat one meal a day of salad and meat and you'll lose weight just like i do! Fad diets don't work!" - and on, and on, and on.
My response "It's not Atkins Mum, it's LCHF, I eat lots of nutrient dense veggies as well as meat and yes, fat. If aunty nevermet went back to eating the way she did pre-diet, then of course she gained weight back, that's how she got fat in the first place."
Mum: "it's all rubbish, you're going to get really poorly if you carry on!"
Me: "Mum, I've lost 13lbs in 3 weeks..."
Mum: ".... well it's probably all water!".... 
Me: "Ok, well it's a shame you can't support me. That would be great, but if you can't then all i ask is that we don't talk about diet or weightloss when we see each other"
Mum: "You should do slimfast again, you lost weight on that"
Me: "I was 9 years old and lost a stone in a month, then gained 2 the following 6 months because I binge ate like mad when I was at school"
Mum "well that was your fault for not sticking to it"
Me: "ok Mum."
Mum: "We'll see who's right when you've got diabetes and a size 20 wedding dress!"
Me: "Ok Mum" and repeat.
I left feeling furious, so I sent her the LCHF lecture via a youtube link. This morning I got a reply: I'm sorry I came across so negative last night, I do support you and well done for losing so well in the last few weeks".
Mum: 0, Jim: 1. 