The basic theory is that supposedly the energy required in it's digestion and utilisation is more than the amount of energy in the lettuce itself. Now of course, intuitively that would imply that this is a 'negative calorie' food and loses you weight. But alot of physiologists and dieticians are skeptical of it due to a plethora of more complicated reasons. *shrugs* Whether or not negative calorie foods are legit, it's still good for you to eat lettuce, because alot of it is just water weight and hence overall lettuce is low in calories (and fills you up).Korn said:Well as i have been told eating lettuce burns more calories then it contains so it makes u lose weight, as weight lose is all about using more calories then you consume
As for 'weight loss is about using more calories than you consume', there's speculation about the validity of that on using it too literally, because many factors come into play. Most importantly, calories burnt off can come from many sources, such as the carbs you consume, the protein you have (muscle mass) or body fat itself. Hence the nature of your diet can be very important. For example, assume your maintainance caloric total is about 2,500, if you eat 6 small meals a day with minimal sugar and saturated fats (2,000 calories worth), chances are you'll lose some body fat. But if you just ate a huge stock of lollies in one meal (2,000 calories worth).. and that was your day's diet.. you won't lose weight. Chances are, you might even gain weight. How? Because the huge insulin spike generated by the sugar will instigate a huge amount of those carbs from the lollies to be converted to fat via the liver. And since you ate only one meal, you'll lose alot of muscle mass too (as low glycogen stores instigate the body to utilise some protein for energy). So overall, you lost muscle mass and gained body fat.