What is the best amount of weight to loose a week and keep it off after its gone?

1-2 pounds/week: Most physicians don't recommend losing more than 1-2 pounds/week, unlike what you see on nbc's biggest loser. Yes, that can be done w/tremendous benefit but it takes more effort & resources than most of us have. Instead, try for a combination of regular physical activity plus healthy eating leading to a calorie deficit of 500-1, 000kcal/d which will lead to 1-2 pound/wk loss. Think lifestyle change.