What is the least anout of time to lose about 10lbs ?

Lose weight safely: It depends on how much you are overweight if you are and how much you want to lose. A good estimate is one to two pounds per week but this is with caloric control and good hydration. If you are anorexic you do not want to lose weight. consult with your doctor on the best method to do so.

Losing weight fast: is never a good idea. It certainly isn't a way to keep the weight off. I believe you shouldn't lose more than a pound a week safely, to allow your body to adjust. It's usually about what and how often you are eating that affects your weight. Eating small meals but with lots of protein, veggies, low on the carbohydrates (breads and pastas are my weakness) and sugars. Hope that helps