Am planning on drinking three shakes a day and my height is 5ཆ and my weight is 180 and am 19.
How much would I lose doing this for a month? And what should be my goal weight? Someone told me 125 should but I want other opinions too.

don't do that!!! it is very bad!! follow a sensible diet and take a Multi-vitamin everyday. also, about your ? for losing 100lbs in a month. WHY???? you want to weigh 80 pounds??? that is crazy. not many grown women weigh that much!!! the ones that do are like 4ཇ''- 5ƈ'' and some of them look malnurishhed (very bad thing). you should only want to lose 30-40lbs and 50 AT THE MOST. anyway, keep your head up

You're not supposed to drink 3 shakes a day. I have done two different diets where I drank 2 shakes a day and then a meal. The meal would consist of lean protein and some veggies. I also drank a lot of water, and had fruit if I was hungry and needed a snack. I lost around 10-15 lbs/month. You are also very tall and I would think that 125 might be too light for you. Accoring to a height weight chart if you have a small frame 132-145 would be the range for you. Check this out for more info http://www.healthchecksystems.com/height...