Dont skip breakfast, this si the worst idea ever. Make sure you have something at any rate.
Bin the meal deal, prepacked sandwiches arent all bad, and if you get water thats ok, but the bag of sweets/ crisps is never a good thing.
evening meal, you havent said what, but try and avoid the obvious pizza/takeaway.
If you snack at work or whatever, try a bag of apples/pears/bananas or whatever instead.
Everyone will call you a gay, but stop drinking beer and start drinking spirits and mixer instead, preferably diet (for an event last year we all needed to dip for the team weight limit, so the whole sailing team were of beer for 2 months)
And then, as above, take any oportunity you can for exercise, take the stairs instead of the lift, walk when you can, and try and get a litle done in the morning/evening.