Don't turn your heating on over the winter and give all your jumpers away now (they need them - record numbers of thefts apparently!). Shiver yourself thin. Maybe.
More seriously, I'm firmly in the exercise AND eat well camp. Whap a search into google, read some training articles (like the Matt Hart ones on here - they're pitched at a nice, general level), or could you ring the guys you're applying to for advice (sorry, not idea if this is au faix in the military or not!).
One thing though - don't go for quick 'fad' diets, they never work.
And to echo what others have said about calories. Check what you eat really carefully. That salad you had - any fatty dressing?(I've just been trying cutting out dairy products from my diet to sort out stomach problems I've had 4 years - I really struggled at first as I had NO idea I ate so much. (Dairy, that is!) It's working though!)
EDIT - I've not really said anything here, have I?! What I meant was, go over what you eat again and keep up the exercise - but perhaps following some really structured advice (you're running stuff is good, but probably not enough to loose weight, assuming you're already relatively fit from biking). Unless you're entirely muscle, you will loose fat it you consume less energy than you expend - but you've got make sure you're still eating well.