Limiting salt and starches may also mean losing more weight at first -- but that's mostly fluids, not fat.
For rapid weight loss,focus on fruits, veggies, egg whites, soy products, skinless poultry breasts, fish, shellfish, nonfat dairy foods, and 95% lean meat.
Here are more tips :
-Eat vegetables to help you feel full.
-Drink plenty of water.
-Get tempting foods out of your home.
-Stay busy -- you don't want to eat just because you're bored.
-Eat only from a plate, while seated at a table. No grazing in front of the 'fridge.
-Don't skip meals.
-Keeping a food journal -- writing down everything you eat -- can also help you stay on track..
-Plan to do cardio and strength training.
Faster than this ,will be surgery.
NOTE: if you have a medical condition that is related to your weight gain then treating the cause will make you lose weight better while if losing weight without teating the condition you will gain again the weight you lost.