The other crucial factors in losing weight, if you need to, is in always having a decent breakfast. Quite simply, it'll stave off the need to snack before lunch and the tendency to eat crap, and if you're active (working or otherwise), you should burn off the calories, plus a good breakfast will give you the energy you need to get through a working day.
Then try and have your main meal at lunchtime, not always easy I know, but again if you're active you'll burn off most of the calories (depending of course on what you eat) before the end of the day. The absolute worst thing you can do, in my experience, is having your main meal late at night, and then simply sleeping on it, especially if alcohol is involved - that is one SURE way of piling on the pounds! And usually also feeling pretty lethargic the next day.
As the old saying goes: "Eat breakfast like a king, lunch like a prince, and dinner like a pauper”. If you can manage that, and combine it with adequate levels of exercise, you'll be unlikely to have any weight issues. It really does work:)
Plus, as Andre touches upon, staying properly hydrated by drinking plenty of water is also crucial, just to feeling healthy and alert in general, but it also flushes out your system and staves off hunger pangs. Drinking fizzy drinks/pop is also one of the best ways of putting on weight, due to all the sugar, so try and get used to drinking water or tea/coffee in moderation without sugar or full-fat milk, as opposed to anything sugary.
Marco.