Whenever we hear the words "diet" and "calories" in the same sentence, the first things that come to mind are a grueling struggle against hunger and that dazed feeling you're left with after you've been staring at your plate for far too long, trying to figure out exactly how many calories you have on your lunch plate. And that is partly true - the counting calories part, anyway - however, few of us are aware of the fact that inside any diet that imposes a maximum of around 2000 calories a day there's a secret loophole, a little doorway that you can discover and of which you can take advantage to offer yourself occasional treats that will not affect your overall weight loss goals. Here's how you do it.

Think of your daily calorie intake as your spending budget. You can "spend" - that is, eat - 2000 calories a day. The overall budget is made up of essentials and what we could call "added bonuses". The essentials are the minimum of calories your body needs to fully meet its nutrient needs. If you decide to go for the fat-free, no-sugar-added versions of the foods in your diet plan, you could go for the old "more for less" cliché and manage to get all the nutrients you need but still use up less than your overall 2000 calorie budget, and thus be left with a little extra on the side. This is your added bonus, otherwise known as "discretionary calories".

If you're on a 2000 calories a day diet, you will normally need to spend at least 1,700 of them on essential aliments such as protein, vitamins and minerals. The other approximately 300 units are yours to use whichever way you choose. You could eat a larger portion of one of the foods you already included in your basic diet - a larger helping of meat, for example. You could drink a small amount of alcohol, add a little sugar in your morning cereals or add a more consistent dressing to your salad. Of course, you still need to be careful, as it's quite easy to "overspend" and eat more than you'd like to. But when you're on a diet, even a little bit of sugar sprinkled over your whole-grain cereal with low-fat milk may make your day.