She aims to put on a stone and a half in a year.

Each week Lizzie posts part of her diary describing how she is finding the challenge.

To sponsor Lizzie visit www.justgiving.com/lizziegrimaldi.

Diary entry: 25th March
Another minor increase. This is proving too difficult to sustain on my own. Perhaps hospital is the solution. I just cannot face it. I can't make that decision. There needs to be another way - this way. I have to take a deep breath and remind myself of why I am doing this, what I need to do, how I have to do it and then just get on with it. Without thinking too much. I tend to overthink everything and blow it all out of proportion. It's not that hard so don't make it. I have to sign a mental contract to adhere to the programme and constantly remind myself of it. Or hospital it is.

Diary entry: 26th March
I think a slight change of tactic is called for. At probably the same time, Hannah realised she had bitten off more than she could chew and I realised I was expecting too much of her. So I am relieving her of her food-related duties and instead have drawn up my own meal plan in tandem with a signed contract drawn up by the dreaded husband which basically states that I agree to gain a pound a week (or I go into hospital), that I address my food-associated behaviours (or I go into hospital), that I stick to my mealplan (or I go into hospital), that I stop blaming everyone (including myself) and accept that this is an illness (or I go...) etc etc. My terms, my decisions. And so far, so good. Watch this (ever increasing) space.

Diary entry: 31st March
Well, I'm sticking to it. Signing on the dotted line seems to have made a difference. Minor clocks going forward-related misunderstanding at lunchtime yesterday threatened to throw the whole thing into disarray but by walking away, taking several deep breaths (and several swigs of rescue remedy) and locating a new frame of mind, the situation was diffused. And the afternoon snack was a breeze (well, tea and biscuits actually). But the only true indication of whether this is working will be on the scales. So lets just keep fingers, toes, eyes crossed for tomorrow. It may not be the whole pound of flesh which is demanded of me but it'll certainly be more than the paltry 100g of the past few weeks.

Diary entry: 1st April
A slightly better increase than last week (0.2kg) - more of a toddler step perhaps? but still pretty insignificant. I think we could have all done with a giant stride this week, but hey, at least it is still heading in the right direction. And we are only 2 days into the new contract.