Food. Strict control. Do anything else u want to but diet HAS to be the single most important item in your list.
Keep your body in calorie deficit mode. Check your weight everyday if you can.
Have a pig day in a week where you eat anything you wish. Not a good idea for your body get a state of familiarism. Drink at least 4 litres of water. Rather than avoiding food, eat proper. Have atleast salads and fruits as your lunch 2 or 3 days. Or 2 or 3 chapathis with some veggies and dal or so.
Less oil in everything. Avoid sweet, Strict. Until you reach your desired body weight and you can are under control. Dinner, always.. I mean always light. 300 to 400 calorie. I eat like nuts, thin crackers..britannia chai biskuits.fruits...nowadays ice cream sandwich(250Cal)(dont try this now though..but once you are ok with your weight). Always intervals of 2 hours between meal or snacks. Avoid atta or flour items. No white bread. No burgers/sandwich (I love sandwiches

). Unless its your pig day.

. Mine is Friday dinner. I eat like a pig.

. Rice is a source of carbohydrates. So no Rice either. and I am from south India.

. Yea going out will be tough, but what do you want.
Trust me, due to my paranoid food control I have lost something that may have been something amazing. but looking back what i gain outweighs that. I am not going to explain what. You may need to make many sacrifice if you want to get what you want. But You have to take the call, your body or what others want. But trust me, it is worth the pain.
A good fit body can go long way in boosting your confidence, ego, arrogance in no unexplainable terms. And there are certain other advantages also

. So yea, I am strict about my diet. Unless i am home. Will eat whatever my mother cooks me... I mean screw diet then. hehehheh. But she knows and cooks appropriately. I am a animal when it comes to food. I eat anything that moves. But now. Non veg only on 4 times a week. Unless its Friday dinner. 3 days pure Veg. If you want to have chicken, have grilled or boiled. if you want to have sandwich, have a salad. If you eat beef, have a nice juicy grilled steak other than any oily preparations. Just start doing everything. there is no one item or one. The reason is its your body. What may work for me wont for you. Experiment and see what is affecting you. Taking a daily weight reading will help you. I travel a lot. I lug around 2kg weight scale. in my 23kg baggage allowance.
If alchohol is in your lifestyle, avoid for atleast the day you are ok with your weight. Or have it in your pig day.
I was like 120 Kg+ Now between 79 and 82KG. Planning to keep it like that. No exercise for 2 months now.

. Sad about that though.