Weight loss can either occur unintentionally due to malnourishment or an underlying disease or arise from a conscious effort to improve an actual or perceived overweight or obese state. "Unexplained" weight loss that is not caused by reduction in calorific intake or exercise is called cachexia and may be a symptom of a serious medical condition. Intentional weight loss is commonly referred to as slimming.
Successfully managing your weight comes down to a simple equation: If you eat more calories than you burn, you gain weight. And if you eat fewer calories than you burn, you lose weight. Sounds easy, right? Then why is losing weight so hard? Well for one, weight loss isn’t a linear event over time. When you cut calories, you may drop a pound or so each week for the first few weeks, for example, and then something changes. You eat the same number of calories but you lose less weight. And then the next week you don’t lose anything at all.
That’s because when you lose weight you’re losing water and lean tissue as well as fat, your metabolism slows, and your body changes in other ways. So, in order to continue dropping weight each week, you’ll need to continue cutting calories.
Secondly, while in essence a calorie is a calorie, your body reacts differently to different types of food. So eating 100 calories of high fructose corn syrup, for example, will have a different effect on your body than eating 100 calories of broccoli.
The trick for sustained weight loss is to ditch the foods that are packed with calories but don’t make you feel full (like candy) and replace them with foods that fill you up without being loaded with calories (like vegetables).
