Exercise with cardio, especially swimming laps, is a great way to lose fat. Diet wise, I always joke and say a liquid diet. I've had to be on one a couple of times for times when i'm backed up and when I had my stomach surgery to fix my acid reflux. I lost a lot of weight on it and it wasn't fun. Gaining all that weight back was really difficult and took me a year and a half to get it all back,but it works. Talk to your doctor first though.
The best way I experienced fast weight loss was Cholera. I don't recommend this but rapid weight loss depends on what and where the weight is. My brother wrestled in highschool and college. Unless you are wrestling heavy weight, most wrestlers will try to make the lightest weight class at their size.
Bob gained muscle mass in his three years of highschool wrestling and the weight classes went 145#, 154#, and 165# for him. The wrestlers ran laps around the boiler room dressed in winter clothes. I've seen 5 pounds dropped in a single workout.
I'm sorry for your dilemma but the most reliable and healthy means is diet and exercise. Diet shakes that have good reviews and 30 minutes of daily cardiovascular exercise designed to naturally ignite fat burning metabolism, one that you do your cardio workout daily about the same time. Change the diet and you can gain weight so realize that they have to be chosen together.
Hmm... I'm not really sure about losing fat so quickly. In almost every aspect, acquiring something too fast may cause side-effect. Take most Western medicine for example (note: I don't mean to judge anything, this is just my opinion), most medicine has some sort of chemical substance in it and using too much or in wrong way can cause serious health problem, for example like the antibiotic.
And so if I may I would suggest reducing fat in slow, but healthier method: combining exercises and diet. Going for body building can also be nice way for it.
Fat loss is at top on the list for many individuals when it comes to look healthy and fit. But practically losing fat is not easier. I am going to suggest some best methods to lose fats but these methods only work if you will do them well.
First remove the fast carbs such as bread, pasta and rice (which are called processed food).
Second eat more foods that are rich in proteins is necessary for losing fat and make you slim. You can get the proteins from eggs, meat, fish and nuts along with the vegetables and fruits.