I know you probably don't want to hear this but losing weight too fast is unhealthy and you are more likely to gain it back and then some.
Strict diets that drastically reduce calories may work in the short term but will fail eventually. Your body will crave more calories and go into a starvation mode. This means that your body will hold onto every calorie it gets and store it since it believes you are starving. Once you begin to eat normally again (you will an your appetite will be more then it had been previous) your metabolism will still be in starvation mode and you will gain all the weight back.
The best long term advice to keep fit is to eat a variety of healthy foods. Eat smaller meals frequently to help stabilize blood sugar levels so you feel energized and feel fuller longer. Eat complex carbohydrates (reduce the amount of white bread, rice,...), and try not to consume high carbohydrate food items after 6:00 pm. Exercise daily, weekly exercise should consist of weight training (builds muscle that burns more fat and calories at rest), cardio (for endurance, fat burning and heart health) and stretching (can be yoga, pilates, for joint health and reduce the amount of injuries to the body during strain/exercise). Drink water for thirst, by cutting out fruit juice (eat the fruit don't drink just the juice, eating the fruit will make you feel more full and will increase fiber intake) soda (regular and diet, studies have shown that diet soda drinkers consume more calories on average because they feel they are saving calories drinking diet soda) and other sugary drinks you will lose weight.
Hope this helps.
I am a registered nurse RN BScN