I've read the "sticky" message with FAQs about calorie recommendations but it didn't address this issue, so I thought I'd post it here (I wrote about this in a recent blog message as well)
For years, I was under the impression that I could calculate my “maintenance” calorie intake by multiplying my current weight by 12 (since I’m sedentary). After all, this is the common equation quoted on most websites and in most books — and some are even more generous.
“You need approximately 2891 calories per day to maintain your current weight, based on your current activity level…. To take off 1 pound per week, you need to create a “deficit” of 500 calories per day. You can do this by eating 250 fewer calories a day (for example, cut out a 20-ounce bottle of regular soda) and burning an extra 250 calories through physical activity (for example, walk for 2.5 miles).”
According to this equation, I could consumer 2,391 calories a day and still lose a pound a week.
Something about this was just too good to be true, so I started do a bit more research and found that there’s another “equation” that gives a far different result.
The second method of figuring out your caloric needs is by calculating your Basal Metabolic Rate (BMR). Using the Harris-Benedict formula, my BMR is 1,602 calories. Then, using figures found on many websites, I multiplied my BMR by 1.2 to arrive at the number of calories I need to maintain my current weight.
That came to 1,923, give or take a fraction of a calorie. For my one-pound-a-week loss, I can eat no more than 1,423 calories a day.
How can one formula say I can eat 2,391 calories a day but another tell me to restrict my diet to 1,423 calories? Am I not understanding the advice?
I think their calculator is just very, very flawed. It's telling me my level to maintain is 3643! There's no way that's true, I'd be running a calorie deficit of over 2000 a day and losing over 4 lbs a week, and that's not even remotely close to happening.
There is obviously some subjectivity in how these various sites are designed and what formulas they use. Personally, I've heard 10-12x weight for maintenance and 7x weight for loss, which puts me in a range that feels about right to me.
Calculators are a source of endless frustration to dieters because we can't figure out why our bodies don't work the way the calculators say they should work. In reality, the problem isn't with our body -- it's with the calculators. At best, a calculator is an educated guesstimate and at worse, it's wildly and laughably wrong. There are literally dozens of calculators out there that purport to tell us how many calories we can eat to maintain or to lose weight. With dozens of different results. Yikes! What to do?
Forget calculators. The only calculator we need is our own body. It will tell us everything we need to know about calories to lose weight, calories to gain weight , and calories to maintain once we get to goal. Each one of us has a unique metabolism and it might be completely different than another person's, even at the same height, weight, age, and gender. Unless we're locked in a lab and all our metabolic functions measured for a week, no one can predict what specific calorie level will work for each of us.
Here's what I suggest: Take a look at all those contradictory numbers and pick what looks to be a reasonable calorie level for weight loss. For example, I picked 1600 calories when I weighed 257 pounds. Weigh and measure your portions and track your calorie intake for a week. Then weigh yourself. If you've lost weight (and it might be quite a bit for the first few weeks due to water weight loss), then great -- keep on going at that calorie level for another week and then reassess. If you've stayed the same or (oops!) gained weight, then you know that calorie level is too high for you and you need to drop by 100 - 200 calories/day. Try the reduced calorie level for a week, weigh yourself, and reevaluate your loss.
Week by week, track your calories and monitor your progress. Tweak as needed. That's how you'll get to goal.
It doesn't matter what a calculator says. Listen to your body and it will tell you everything you need to know about calories for weight loss.
I'm sure you're absolutely right, but for those of us just starting (or, as in my case, "re-starting") on a diet, listening to our bodies isn't always as simple as it seems. I listen, and it says EAT MORE FOOD. As I continue paying attention to my eating habits, and the way I feel, I think I'll get more intune with my body's messages. But for now, it's nice to have some "instructions" and even be told how many calories I should eat.
I think that's one of the reasons I liked Weight Watchers -- they gave you a set number of points you could have and that was that. No leaving anything to my own discretion (which can't yet be trusted).
I'm at 244 now and I eat around 2125 average per day per week, and am losing 1.5 lbs/week. I get a little exercise in my daily life, but not a lot and I don't "exercise" just to exercise.
The calculator I use at fitwatch.com says my maintainence at my current weight is 2499 calories, and their 15% defecit of that is what I've been using since October. I've lost 24 lbs this way so it works for me.
I'm probably losing more slowly than most people on all these forums are going for, but I want to lose slowly so 1. I have time to adjust emotionally to a new way of eating for life and 2. my body has time to gradually shrink so I don't have flabby skin issues and 3. big calorie deficits make me crazy and make me binge.
There are a lot of calculators and formulas out there, but if you really want to know how many calories you should be eating you should consider seeing a registered dietitian. He/she can tell you how many calories are right for you. My family practice doctor refered me to one. She actually gave me a range 1200-1800 a day(1200 being the min. and 1800 the max) for weight loss; I'm not ready to maintain. I like having a range; it makes it easier than shooting for one magic number.
My weight is sky high. It's 286 lbs. as of thi morning. I know I can lose on 1800 calories going over and over with calculators and also hey, I'm a Nurse 31 years. So what I will be doing is seeing how I do on 1800 calories and try to work a livable approach.
I think you have to see what will work for you and adjust by activity level too. People forget you have to walk, move, get off the couch more.
My thought is I need a snack at night. I have to plan my meals, my menus and have a treat in the day so I can work this and see results.
The other thing si to know which meal needs to be larger. My lunch at work is a 30 min. break but my cravings are worse at lunchtime. Rarely do I muck up dinnertime so on days off it's dinner. Must readjust according to where the problems are and then I should be ok.
i also like an occasional fast food meal. Why not? It's within the calories budget for now. There are smaller versions of fav sandwiches I like and I can leave the mayo out too.
No one can tell you how many calories you will need at maintenance (or how many you are burning now), because there are so many variables. Not everyone who weighs the same amount (even if they're the same gender, height, bone structure, and activity level) will burn the same number of calories.
All the calculators are guesstimates. Many things can influence that number upward or downward. For example, the more diets, especially but not only crash diets you've been on, in your lifetime - and the younger you were when you started dieting, the lower your maintenance calories are likely to be (there've been several studies that found these results - both in women dieters and in men who were competitive wrestlers in school, which often involves periodic dieting to meet their weight class requirements for competition).
Your best tool to find your calorie requirements to maintain or to lose, is your food journal and your scale.
You will probably have to have some trial and error with your own body to know where YOU personally will fall. That higher calorie limit seems really high to me.
3. big calorie deficits make me crazy and make me binge.
That's the boat I'm in. I battle IR, and I've come to find out two things...
1) I can't drop too low or all I'm doing is setting up a binge situation from wacky blood sugar
2) I need to stay away from white flour stuff like bread or muffins or else I'm setting up a binge situation from wack blood sugar
That said I think the American Cancer calculator is off. I think the calorie need calculator at Mass. blue cross blue shiled puts it into the ballpark more.
Big difference in calorie-count advice!
, and calories to maintain once we get to goal. 
Each one of us has a unique metabolism and it might be completely different than another person's, even at the same height, weight, age, and gender. Unless we're locked in a lab and all our metabolic functions measured for a week, no one can predict what specific calorie level will work for each of us. 
