Okay. Here's how you start.
Find a decent calorie calculator online that will tell you an ESTIMATE of the calories you need to maintain your current weight based on your height/weight/age/gender/activity level.
Here's one from the Mayo clinic:
http://www.mayoclinic.com/health/cal...ulator/NU00598
Consider that you must create a 3500 calorie deficit to lose 1 lb. If you reduce calories by 250 a day and add some activity that equals 250 calories a day, you will have a 500 calorie a day deficit. 500 calories a day x 7 days a week = 3500 calories, a safe 1 lb a week weight loss. I am 36 years old, I have "dieted" so many times in the past, I always looked at the math and thought - if I could lose SOME weight by reducing SOME calories, I will lose MORE weight by reducing MORE calories. This is the greatest fallacy I ever believed and it made me go from a 140 lb 18 year old to a 200 lb 35 year old. Don't do it, please.
So, now you have a calorie goal for the day. Now you need a calorie tracker, something like Fitday or Calorieking. They are free, so go ahead and sign up for one. You don't have to count calories forever, but it would be a good idea to journal for a week or two to see HOW and WHY you eat.
After a couple of weeks look at the journal. What kinds of food do you eat? What time of day are you the hungriest? Do you eat because you are sad? Bored? Do you reward yourself if you had a bad day with food? I used to eat in the afternoons because I was bored and the place I worked had a bakery downstairs with a buy 1 get 1 baked good free after 2:00. Chocolate croissants in the afternoon with a venti full fat caramel latte with whip were my downfall. I made plans to combat afternoon snacking - always have a cup of tea, bring healthy snacks to work.
Figure out what you like to eat and try to think how you can eat healthier for your lifetime by making SMALL changes you can sustain forever. For me, this meant cooking with less unhealthy oils, butter and full fat cheeses. I also switched from "empty" carbs to healthier carbs and really bumped up my servings of fruits and vegetables I ate. I also decided to get rid of the foods that I didn't like that much and were terrible for me (fast food, soda, packaged baked goods). I minimized the foods that I liked that were just kinda bad for me (red wine, home made baked goods, dark chocolate, etc).
Plan a week in advance. Everything you are going to eat for breakfast, lunch, dinner, snacks (to meet your healthy calorie goal) for a week. Make a list of the foods you will need to accomplish the plan. Go to the store, buy the foods, eat them. Set aside time to pack lunches, make healthy snacks.
Get a tape measure. Record your measurements. I know it might be painful, but you will be so happy later to have these baseline measurements when you start seeing progress. Record your starting weight.
Make goals that are NOT related to weight that you CAN accomplish. Like - trying one new healthy recipe a week, going to bed on time at least 3 days a week, doing some physical activity 3 days a week, cutting out sugary soda. Eating 4 servings of vegetables a day at least 4 days a week. Sticking to your calorie goals for 5 days. If you stick to your goals for one week, have a non food related reward ready. Pedicure? New sandals? Massage? Reward yourself well for sticking to your goals for a week.
After one week, the healthy food should give you some energy. You should also see a drop in the scale that should motivate you to continue. All it takes is ONE meal, one day, one week.
You can do it. Look at those before pictures of me. I used to eat so badly, a sample of my old menu: B - cranberry walnut muffin, venti caramel latte with whip, no snack, lunch - pizza, snack - pastry, snack - M&Ms out of the snack machine, snack - another venti caramel latte with whip, D - taco bell. Look at my Fitday menu now. I made these changes, I don't miss the old foods. I'm wearing a brand new pair of sexy Old Navy low rise bootcut jeans in a size 8. My life is 100% better.
You can do this. If I can do this, you can do this.