How much weight and how fast are we talking? Losing weight fast is a little dangerous because the second you stop whatever it is you're doing, then you'll gain it all back. A healthy gain is about 1-2 pounds a week.
Here are some tips to help tweak your daily life style so that you can lose weight and keep weight off.
Drink plenty of Water
The more water you drink the better. Try to cut out all caffeine drinks and sugary juices (this includes most fruit juices).
Exercise
I suggest a cardio 2-3 days a week and weight training 2-3 days a week so that you can be burning calories and gaining muscle. Keep two days for rest from intense training, but being active is always a good thing. Whatever days you decide, try and put cardio between weight training days.
Fiber
Fiber is good for losing weight, but be sure to add it in gradually and pair it with lots of water. Too much fiber too fast can have some negative side effects, and even a good amount of fiber without water could be bad too. So basically, eat foods with fiber and drink water
Watch Calorie Intake
Losing weight is simply burning more calories than you take in, and this will be easier if you lower your calorie intake. It doesn’t have to be extreme, but just cut out unnecessary calories where you can.
Speed up metabolism
Eating 4-6 small meals a day can help speed your metabolism. These are
small portion meals and you're still going to have to watch your calorie intake with these. Small snacks throughout the day are good too, as long as its something healthy-- like veggies or fruits.
Long term weight loss is the way to go. If you eat a balanced diet and exercise you will lose weight, however I will warn you that once you start working out there may be an initial gain due to fats turning to muscle.
Let me know if you need anything else. I'll see if I can find something healthy for losing weight quickly but I really think the best way would be to lose gradually and then keep it off yes?