There are two ways to lose weight:
1. Eat less than you burn (change what you eat or how you eat to consume less calories)
2. Burn more calories than you eat (become more active)
So how do you know how many calories your body needs to maintain or to lose weight? Your body uses about 10 calories per pound just to function each day (sedentary lifestyle). If you weigh 180lbs then your body uses 1800 calories a day. In order to lose weight, you need to eat less calories than your body burns, forcing it to draw from fat stores to make up the difference.
An aggressive but solid weight loss plan would be to take in 7 calories per lb. The same person weighing 180 lbs will then need 1260 calories per day, or 540 calories less than the body needs to function.
3500 calories = one pound. That means that if you eat 3500 less calories in the week you will lose a little over one pound a week. The 180 lb person cutting back 540 calories a day will lose one pound a week. 540 (calories cut back ea day) X 7 (days in wk) = 3780 (calories cut back in one week) which equates to 1.08 lbs lost per week.
Note: It's not healthy to drop below 1000 calories a day for more than a couple of days. If 7 calories per pound equals less than 1000 calories for you, it is better to eat at least 1000 calories and increase your exercise to burn more calories.
The second way to lose weight is to burn more calories than you eat. Everything you do burns calories. If you keep your caloric intake the same while increasing your activity to burn 500 more calories a day, you will lose one pound a week. If you burn an extra 1000 calories a day you will lose 2 pounds a week from exercise alone.
Note: If you increase the amount of food you are eating it will offset that exercise and you won't lose weight. This alone is a great reason to keep a food journal. It is motivating at the end of the day to see your caloric intake and your calories burned.
What if you cut back by 500 calories a day and also burn 500 calories a day in extra activities? You will lose 2 pounds a week. However, if you stick to this religiously you may find that you have lost 10 lbs at the end of the month instead of just the 8 you expected. Regular exercise increases your metabolism and keeps your body burning calories at a higher rate for hours after you stop exercising.
There is a reason everyone in the fitness and weight loss industry keeps harping on keeping a food journal and recording EVERY SINGLE bite you put in your mouth. That is truly the only way to know exactly how many calories you are eating. If you also track your exercise you can know if you are burning more calories than you are eating.
There are several free websites that provide an excellent way to track both your food intake as well as calories burned through exercise. Each has different features. Try them out and see which you prefer.
http://www.livestrong.com/ (will even give you calories for your favorite restaurant food)
http://sparkpeople.com/ (also tracks restaurant food)
http://fitday.com/ (has nice charts that can be motivating)
http://www.mytrainerbob.com/ (if you are a Bob Harper fan)
There are several APP's available for use on your smart phone as well.
You can also get the calorie count for food and exercise from websites or books and keep track of it in a paper journal if you prefer.
It has been proven time and time again that individuals who keep a food journal (paper or online) repeatedly lose more weight and lose it faster than those who don't track their food intake. I don't like to admit this, but I have proven to myself that it is true. I don't like to admit it because I consider myself a fairly intelligent person who is knowledgeable about health and nutrition. I like to think that I can 'do it' without having to write every little thing down.
But I'm here to tell you that I did track every little thing I ate on an online program when I was losing 10-12 lbs a month. Every 7 calorie strawberry that went into my mouth was accounted for. I have tried to do it lately (working on the last lbs to lose) 'in my head'. IT'S NOT WORKING!
There is something about having to look at it on paper that makes you stop and think, "I don't want to write this down, so I won't eat it". Or, in figuring out how many calories to write down, you think "Wow, that's a lot of calories for that little thing...not worth it!" Something about having to face (written down in front of you) every bite of cookie or biscuit or peanut butter treat that holds you accountable to yourself.
Again, let me say that I hate that this is a fact of human nature...I want to be better than that! But I know from experience that I can maintain my weight with no problem but when I want to lose I must keep a food journal.
Have you tried keeping a food journal? If not, why not? If so, what is your experience? Would you willing to do it if you felt it would 'guarantee' weight loss?
Which online tracking tool is your favorite and why?