So, How Many Calories Do I Really Need?

The short answer is I’m not really sure. Depending on who you talk to or what you read, the number of calories you need depends on things like your current weight, height, age, level of activity, metabolism rate, and usually another set of (seemingly) random numbers. The long answer is the rest if this article:

My Own Numbers
Looking around on the web, I’ve seen a number of calculations which allow me to figure out exactly how many calories I need to maintain, gain, or lose weight. Here are some of them:

(Note that for all of these I’ll be using my own stats: I do light activity, walking 3 times per week, about 3 miles per day. Some weeks i do more, but recently this has been the pattern. I’m currently at 271.4 lbs (or 123.104 kg), 6’1 ft (or about 1.83m), and 28 years old. Oh, and male. Can’t forget that part. And since some of the numbers I’ll be running are in pounds, you folks using the metric system can use this handy dandy converter.)

Calculation 1

  1. First, calculate your base metabolic rate (BMR), or how many calories you burn by simply existing, though hopefully you’re doing more than just laying in bed and watching daytime television, and therefore simply “existing.” (Unless you’re in the hospital getting better, then in which case, for the love of God, stay in bed watching daytime television so you can continue existing, at least corporeally. And better yet, instead of watching TV, read. Like you’re doing now.)
    • If you’re female:
      BMR = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years)
    • If you’re male:
      BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) – (6.8 x age in years)

    For me, this would be the following: BMR = 66 + (6.23 x 271.4) + (12.7 x 73) – (6.8 x 28) = 2865.45.

    (I know this seems like a lot, but… well, frankly, this isn’t the only one, and it’s the most conservative equation I’ve yet found.)

  2. Second, calculate your daily activity. If you exercise above and beyond simply walking to your car or through the grocery store, then this is where you put it. (Of course, if you walk miles to your car or spend hours scooting up and down the isles at the grocery stores, then by all means count that as exercise, I guess. In fact, forget I said anything about cars or stores.)
    • If you get little or no exercise (leading a sedentary lifestyle), take your calculated BMR and multiply it by 1.2.
    • If you get some exercise (light exercise 1 to 3 times per week), take your calculated BMR and multiply it by 1.375.
    • If you get a moderate amount of exercise (exercise 3 to 5 times per week and do the equivalent of 20 miles weekly, walking 3-4 miles per hour), take your calculated BMR and multiply it by 1.55.
    • If you’re into hard exercise (very active, and working out 5 or more times per week, full workouts), take your calculated BMR and multiply it by 1.725.
    • If you’re a mountain climber, lumberjack or polar explorer (or anything that would be defined as “extra active”, meaning very hard exercise and a physical job or rigorous training), take your calculated BMR and multiply it by 1.9.

    (To see how different activities compare to others as far as burning calories is concerned, check out this article from the Harvard Medical School.

    In my case, I’m in the light exercise category, though I sometimes go to the moderate exercise category, and sometimes, rarely, I’m totally lazy. (I haven’t done hard exercise in a few months.) Using my previous BMR, for light exercise, I need 2865.45 x 1.375, or 3939 calories per day if I don’t wish to lose or gain weight. If I’m not exercising (and not laying in a hospital bed, then I need 2865.45 x 1.2, or 3438.54 calories per day if I don’t wish to lose or gain weight. At least, according to this formula, though it seems kind of high to me. Of course, being at 271.4 lbs, if I don’t do any exercise, then I’ll probably end up with diabetes. Needless to say, this is less than desired.

    So, if I wanted to lose weight, I should probably either eat 500 calories less per day than the required for my daily activity, exercise a lot more, or do a combination of the two, by eating less and exercising. (I’ve been taking that last approach recently, and have lost about a pound a week since January 1 of this year. I started the year at about 276.5. I can’t say it’s even felt like trying, really. When I want to feel “full”, I stuff myself full of salad, and always make my own mostly-vinegar based dressings. I also don’t really drink sodas, don’t eat fatty meats, don’t eat pasta or too much bread, and my only real big sinful pleasure is a Starbucks Frappuccino. A few times a week. Though I make it a point to exercise some more on the days I do have one.)

    If I wanted to maintain the same weight… well, I’d probably eat more and do some exercise. check out this bit from the Harvard article linked above:

    A sedentary (inactive) lifestyle increases the chances of becoming overweight and developing a number of chronic diseases. Exercise or regular physical activity helps many of the body’s systems function better and keeps a host of diseases at bay. According to the US Surgeon General’s report, Physical Activity and Health (1), regular physical activity:

    • improves your chances of living longer and living healthier
    • helps protect you from developing heart disease or its precursors, high blood pressure and high cholesterol
    • helps protect you from developing certain cancers, including colon and breast cancer
    • helps prevent or control type 2 diabetes (what was once called adult-onset diabetes)
    • helps prevent arthritis and may help relieve pain and stiffness in people with this condition
    • helps prevent the insidious loss of bone known as osteoporosis
    • reduces the risk of falling among older adults
    • relieves symptoms of depression and anxiety and improves mood
    • controls weight

    Finally, if I wanted to gain weight, I’d probably exercise more (if I wasn’t already) and eat more of the right foods. (And no, the Starbucks Frappuccino is not a “right food”, I know. But… well, it’s not all that bad. At least if you get the light one. Check out the nutrition info on the Starbucks site, or better yet, check out the Calorie King database.)

Calculation 2

  1. First, figure out your BMR by taking your current body weight (in pounds) and multiplying it by 11. In my case, this is 271.4 x 11, or 2985.4. Again, the BMR (base metabolic rate) is the number of calories you use up by simply existing. (I wonder what Descartes would say about that?)
  2. Second, figure out your metabolic factor. This is where you take into consideration what you feel your metabolism is like. For example:
    • if you look at a taco the wrong way, or breathe in too deeply at a restaurant, do you start gaining weight? (“Is it just me, or did the air just get fatter?”) And is it hard for you to take off weight, even when dieting? Then you, my friend, have a slow metabolism, and you’re probably one of these people who have been “heavyset” all their lives. (I count myself among this number.)
    • Now, what if it’s not that bad for you? What if you’re the type that can gain weight if you try (or simply ignore all conventional rules of health) and don’t have much trouble losing weight if you really want to? Then you probably have a moderate metabolism, and you’re probably not fat, but you’re not skinny either. And it’s probably been that way most of your life.
    • Finally, we have the high metabolism folks. You’re the envy of the industrialized world, the person who can eat just about anything and still look great in a bathing suit. For you, gaining weight is pretty hard, and you’ve likely always been the skinny kid. And if you want to lose weight–though you probably don’t–then it’s as easy as thinking about it, or at least it seems that way to the rest of us.

    Now it’s time to pick your metabolic percentage:

    • For you with slow metabolisms, here is your metabolic percentage, based on your age:
      • Under 30 years of age: 30%
      • 30 – 40 years of age: 25%
      • Over 40 years of age: 20%
    • For you with moderate metabolisms, here’s your metabolic percentage, based on your age:
      • Under 30 years of age: 40%
      • 30 – 40 years of age: 35%
      • Over 40 years of age: 30%
    • For you with fast metabolisms, here’s your metabolic percentage, based on your age:
      • Under 30 years of age: 50%
      • 30 – 40 years of age: 45%
      • Over 40 years of age: 40%
  3. Now, multiply your BMR by your metabolic percentage to get your metabolic factor. Since I’m 28 and have a slow metabolism, I have a metabolic percentage of 30%. That means that my metabolic factor is 2985.4 x .30, or 895.62.(By the way, you can speed this up with exercise, but not all that much, really. You can maybe move one metabolic level up. For example, if you’re under 30 and have a naturally moderate metabolism, but are a long distance runner, then you probably should use the fast metabolism numbers for your age bracket.)
  4. Finally, add the BMR to the metabolic factor to get your total calories needed per day to maintain your weight. In my case that’s 2985.4 + 895.62, or 3881.02. Like with the previous calculation, this number seems a bit high to me, but whatever.Like before, if you want to lose weight, then you’ll probably want to either cut back 500 calories per day, or do 250 calories more of exercise and cut back 250 calories from your daily intake. If you want to stay the same, then… well, keep your caloric intake, though I’d still recommend exercise. Finally, if you want to gain weight, start eating more of the good foods, and keep exercising.

Online Calculators

If doing math is not your thing, or of you want to see other calculations (like those which take your height and specific age into consideration), then take a look at the following links. These are some of the online calculators I found. Try out a few and see which you like. Most of them will give you different results, though.

As you’ve probably guessed, there are more online, and a simple Google search will turn up a whole internet-load of them.

Conclusion: On Food

Throughout all of this, you’ve seen me say that these numbers seem kind of high. The fact is that they might be, or they might be correct. All of them. But the question stands as to whether they’re correct for me, or more importantly, for you. As of now, I’ve been eating about 2,100 calories per day, though I should probably cut down on the fats (like olive oil, which I use copiously, or nuts) and increase my fruit and vegetable intake. That seems to be working fine, since i allows me to eat like I want without feeling like I’m overeating or under-eating, or like I’m depriving myself of any of the foods I enjoy. Of course, your goals will probably be different. If you’re looking to gain weight through weight training, then you might want to head over to Strong Lifts and see what you should be doing. There’s a ton of info on the web and while all of it isn’t good, it’s usually a good place to start, since it’ll help you develop questions you can ask your doctor, nutritionist, fitness instructor, or the local fitness and nutrition guru.

Of course, one recommendation I (and I’m sure everyone else you talk to) will make is to, at the very least, work at improving the quality of the food you take in. Remember, high-nutrition is what you want, not high calories. (This is the basis of the whole CR movement.) What’s been amazing to me has been the complete shift in my taste buds once I started doing things like watching my sodium intake or eliminating partially hydrogenated oils. I no longer eat Chinese food (well, on very rare occasion, and even then, I can only stomach very little of it), I rarely eat pizza anymore (a special treat for once in a while, but too much makes me feel like crap), I no longer eat fried foods (my stomach just can’t handle them anymore), and I’ve even stopped eating high-glycemic breads, like bagels. The end result has been that my fruits and veggies are now more flavorful than ever, and that I enjoy eating because I can eat until I feel full — which takes less than before — without feeling guilty over the calories, since they come now mostly from salads. (And raisins. I love raisins. Especially in my salad.) I’ve also found that by switching the way I eat, I now eat a lot in the daytime — at 8, 10, lunch at 11:00, snack at 3:00 — and very little at night (dinner at 6:30), which capitalizes on my metabolism cycle.

By the way, if you’re switching what you eat in order to eat healthier, even if you’re eating the same number of calories (and therefore getting more nutritional value for every calorie you put in), you’ll want to watch out for the “healthy fast food” trap. Now, I know most of us will at one point or another tell ourselves, “Hey, that place over there is fast food, but if I get something from their healthy menu, it won’t be bad!” The fact is that many of these places put stuff in the food that otherwise wouldn’t be there. They don’t do this to be evil, mind you, just as a way to mass-produce and mass-distribute the stuff. In fact, check out this article on some of the surprise ingredients in fast food. Now, that’s not to say that eating a Whopper from Burger King is just as bad as a Veggie sub from Subway, but the best thing to do is to buy the food at the grocery store and make it at home. Yes, it’ll take some time, but you’ll be much healthier and happier for it.

I hope you’ve found this article helpful. If you have, or if you have any questions, feel free to post them there! Finally, remember that when it comes to what to eat, how much to eat and when to eat, the rules are simple: Eat food. Not too much. Mostly vegetables.

6 thoughts on “So, How Many Calories Do I Really Need?

  1. Those calculations are interesting. I’d be they’re great a general rule of thumb, but there’s too much variation in biology person to person to use them as a rule.

    According to the first calculator, I need about 2600 calories a day just existing. I fall into moderate exercise for the most part, but since I’m not consistent week to week I used the light one. Most days I eat 1900-2200 calories. I don’t lose or gain weight at that level.

  2. Good grief, such a long article. I burnt at least 10 calories just scrolling down it.


    Just kidding of course. I’ve just done my fifteen minutes of DIY workout (which is basically jumping around like a fool to some tunes and lifting the history of Great Britain — two conveniently sized tomes of about a kilo). So I am a tad tired (it’s already close to my bed time, but I think you can tell from the diffuse nature of this comment by now).

    In any case. What I wanted to say was: I’ve been very interested in this stuff recently, doing some exercise, eating properly, but I have been intimidated by the sheer amount of information. So, I’m glad you researched this and shared it in this summary. I’ve bookmarked it an am certainly going to check it out tomorrow.

    Then, perhaps, I may be able to comment on what it actually was you said here, instead of rambling on aimlessly like I have.


  3. In short, eat more. (Healthy stuff, of course.) Also, check your temperature regularly to see what your metabolism is like: the higher the temperature, the higher the metabolism; the lower the temperature, the lower the metabolism. Note that your temperature is different at different times of days, so check for your average (37C or 98.6F is “normal”). The higher your metabolism, the more calories you need to eat.

    I’ve been reading a lot lately about the recommendations of Dr. Andrew Weil, and listening to the available podcasts. I highly recommend these to find which are the best foods to bulk up your diet with.

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