Hey there! As one who lost 70 pounds (I am 5'6", and began at 220 pounds), I can DEFINITELY relate! I'm very glad that you're on your way to a healthier lifestyle. Allow me to give you some tips that got me started.
biggrin
The first step to losing weight is knowing your basal metabolic rate (BMR). This is the amount of calories your body naturally burns each day. Use this one to calculate yours:
BMR Calculator. This step must come first because it will help you determine how much you can eat a day. Make sure to choose the correct activity level by pretending that you aren't working out and choose the option that best fits your lifestyle. If you're like me, you might work out every day, but you still work a desk job or sit at school all day. That's why I choose sedentary.
xp
The next step is to plan your calories according to your BMR. If you want to maximize your weight loss, you want to choose a number below your BMR to create a calorie deficit. My BMR is about 1800, so normally I choose 1200 calories to eat per day. Unfortunately, this is the step that many people fail with - they often choose calorie levels that are too low, end up feeling crazy hungry, and give up with their dieting. That's why it's best to choose something realistic (between 500-700 calories below your BMR is probably good, but choose something that's comfortable for you). Remember that by exercising you are also burning calories, so use an online calculator like
this one to calculate what you're burning.
heart My biggest tip? Log EVERYTHING that you eat! I keep a Word document saved to my desktop and I always list down what I eat and how many calories I take in. There are several great websites now that will tell you the approximate calories of items you have no clue about, too (try
this one)!
heart Make it easy on yourself since you're just starting out - don't worry about fat, carbs, or protein levels for now. Get yourself used to the process of calorie counting and seeing the pounds drop off first.
heart Once you're ready to drop your calories drastically, try not to drop below at least 1200 calories per day. This is the base requirement average-height/weight bodies need for proper organ function, etc.
heart All calculators on fitness machines and calories listed by websites (even those I have listed above) display approximate estimates. Calories burned by exercise are best judged by a heart monitor, but since those are expensive, assume you're burning a little less than what the machines are telling you (if a machine tells me I've burned 200 calories, I usually tell myself I've burned 170).
Once you find your perfect medium between watching calories and exercise, you're going to be perfectly comfortable losing weight AND keeping it off. It won't be easy, though, so keep your chin up and stay positive! You can do this!