Losing 50 or even 30lbs of fat in a month via diet and exercise is incredibly unrealistic. That's mostly going to just be water weight. When I was a fitness trainer, I heard these claims all the time about how so-and-so lost 10lbs in a week. They used a new hit supplement or drug or special diet. While it might technically be true, it's really bullshit.
Boxers, MMA fighters, etc routinely lose several pounds of weight a day or two before weigh-ins and then rehydrate right back up after. They might lose 15lbs in two days and gain 15lbs right back a day later. It's not fat, muscle, etc. It's just water. My own weight often fluctuates +/- 2 to 4 lbs a day.
The problem stems from the goal being to "lose weight". The real goal should be to lose fat. That's what everyone really means when they say they want to lose weight - to lose fat and look better. But when they lump "losing fat" and "losing weight" in as meaning the same thing, they hear claims ("I lost 10lbs in a week") or make bold claims that are just misinformation and sets incredibly unrealistic expectations.
For any that's still reading and interested in how much fat you can actually lose: You're not going to lose 30lbs of fat in 30 days or a lb of fat a day. A much more realistic expectation is between 1-3lbs of fat a week. That isn't strict and varies based on what you weigh, genetics, your calorie deficit, etc, but it's the range that most people working hard at burning fat fall into. Personally, I'm male, weigh around 200lbs, and when I cut, using a very, very strict diet, gym and cardio several times a week, I generally average about 1-2lbs a week of fat loss, which slows as my body fat percentage drops, but that is a rate that I'm very happy with. For someone with a lot more fat starting, you can lose more, but not in the area of 8lbs, 10lbs, whatever. Anything around 2lbs a week is fantastic progress without getting into the realm of the 500+lb super obese. Generally, the higher your body fat index, the greater fat you can lose, and that's really what you should be measuring. A scale is great to see your progress at a glance, but if you're serious about weight loss, you should measure your body fat index, so you know your progress in fat loss, not weight loss. So don't worry about these tall claims. If the scale is consistently dropping a small amount each week, you're making progress. It's not a sprint, it's a marathon.