# Do I really need 3000 calories a day?

**URL:** <https://boards.straightdope.com/t/do-i-really-need-3000-calories-a-day/202839>\
**Category:** Factual Questions\
**Created:** [September 20, 2003, 7:41pm UTC](https://boards.straightdope.com/t/do-i-really-need-3000-calories-a-day/202839 "2003-09-20T19:41:24Z")\
**Posts on this page:** 11\
**Page:** 1

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**Author:** ![Opus1](https://avatars.discourse-cdn.com/v4/letter/o/858c86/32.png) [@Opus1](https://boards.straightdope.com/u/Opus1)\
**Post date:** [September 20, 2003, 7:41pm UTC](https://boards.straightdope.com/t/do-i-really-need-3000-calories-a-day/202839/1 "2003-09-20T19:41:24Z")

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I just got my latest issue of Nutrition Action and it contains a formula for figuring out how many calories you need to maintain your current weight. Here’s the formula, along with my stats (all figures rounded for simplicity)

1. Multiply your age by 9.72 (9.72\*23= 224)
2. Subtract from 864 = 640
3. Multiply weight by 6.46 (6.46\*175=1130)
4. Multiply height in inches by 12.8 (12.8\*68 = 870)
5. Add 3 and 4 = 2000
6. Multiply 5 by your activity level (I’m somewhere between “low active” and “active”, so this gives me either 1.12 \* 2000 = 2240 or 1.27 \* 2000 = 2540)
7. Add 6 and 2 = 2880 or 3180

This seems ridiculously high to me. I remember an old rule of thumb being 12 calories per pound, which would mean that I need only 2100 calories/day to maintain my current weight, which seems far more in line with my intuition.

Is the formula wrong, and if so, what’s the likely mistake? About how many calories a day do I need for my height, weight, and activity level?

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**Author:** ![stereonationpga](https://avatars.discourse-cdn.com/v4/letter/s/53a042/32.png) [@stereonationpga](https://boards.straightdope.com/u/stereonationpga)\
**Post date:** [September 20, 2003, 8:18pm UTC](https://boards.straightdope.com/t/do-i-really-need-3000-calories-a-day/202839/2 "2003-09-20T20:18:35Z")

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it doesnt really matter how many calories you consume in a day. just keep a good diet, eat plenty of fruits and vegetables, avoid fatty snacks and/or desserts. also get some moderate exercise.

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**Author:** ![DreadCthulhu](https://avatars.discourse-cdn.com/v4/letter/d/db5fbb/32.png) [@DreadCthulhu](https://boards.straightdope.com/u/DreadCthulhu)\
**Post date:** [September 20, 2003, 8:32pm UTC](https://boards.straightdope.com/t/do-i-really-need-3000-calories-a-day/202839/3 "2003-09-20T20:32:30Z")

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You need way more than 3000 calories a day. Most people need 2000-3000 kiloCalories to keep their weight on the level.

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**Author:** ![x-ray\_vision](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/x-ray_vision/32/351_2.png) [@x-ray\_vision](https://boards.straightdope.com/u/x-ray_vision)\
**Post date:** [September 20, 2003, 8:36pm UTC](https://boards.straightdope.com/t/do-i-really-need-3000-calories-a-day/202839/4 "2003-09-20T20:36:08Z")

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Where do you get this info that the amount of calories you consume per day doesn’t matter **stereonationgpa**?

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**Author:** ![x-ray\_vision](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/x-ray_vision/32/351_2.png) [@x-ray\_vision](https://boards.straightdope.com/u/x-ray_vision)\
**Post date:** [September 20, 2003, 8:41pm UTC](https://boards.straightdope.com/t/do-i-really-need-3000-calories-a-day/202839/5 "2003-09-20T20:41:57Z")

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I think we can be pretty sure that **Opus1** was talking about Calories, not calories, **DreadCthulhu**.

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**Author:** ![sailor](https://avatars.discourse-cdn.com/v4/letter/s/a587f6/32.png) [@sailor](https://boards.straightdope.com/u/sailor)\
**Post date:** [September 20, 2003, 8:46pm UTC](https://boards.straightdope.com/t/do-i-really-need-3000-calories-a-day/202839/6 "2003-09-20T20:46:44Z")

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It doesn’t matter if you don’t mind getting fat as a blubber whale.

The calculation sounds too complex but it boils down to:

Cal = 864 - 9.72_age + activ_(6.46_Weight + 12.8_Height)

You do not explain how you determine the “activity level”

I believe most calculations take sex into account.

I believe 3000 calories is too much for a sedentary person.

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**Author:** ![Achernar](https://avatars.discourse-cdn.com/v4/letter/a/e274bd/32.png) [@Achernar](https://boards.straightdope.com/u/Achernar)\
**Post date:** [September 20, 2003, 8:53pm UTC](https://boards.straightdope.com/t/do-i-really-need-3000-calories-a-day/202839/7 "2003-09-20T20:53:50Z")

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> [@](#):
>
> \*Originally posted by sailor \*  
> I believe 3000 calories is too much for a sedentary person.

Yes, well, “sedentary” doesn’t go well with “low active”. I’m going to guess that if you have an average activity level, your multiplier is 1. Sedentary would be less than this, maybe 0.9. Does the article say what’s meant by “low active”? Because I would think that to get a multiplier as high as 1.12, you’d have to run a few miles or work out for about an hour a day, in addition to your normal everyday activities. 1.27 could be for athletes.

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**Author:** ![ultrafilter](https://avatars.discourse-cdn.com/v4/letter/u/3d9bf3/32.png) [@ultrafilter](https://boards.straightdope.com/u/ultrafilter)\
**Post date:** [September 20, 2003, 9:43pm UTC](https://boards.straightdope.com/t/do-i-really-need-3000-calories-a-day/202839/8 "2003-09-20T21:43:24Z")

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The calculations offered so far are inaccurate because they don’t take fat mass and fat-free mass into account. Fat mass is metabolically inactive compared to fat-free mass, and that makes quite a difference.

That said, your caloric intake depends largely on your activity level. 3000 calories is roughly suitable for a fairly sedentary person of your height/weight, although you could get by with less or more. Remember, equations are derived from population averages, meaning that it may or may not be good for you.

Also, you didn’t mention your gender. Men and women react differently to a surplus/deficit in caloric intake, so that’s an important bit.

Lastly, what you eat may be as important as how much of it you eat. There are four common beliefs–a calorie is a calorie, a carb is a carb, a fat is a fat, and a protein is a protein–which are very likely wrong. Have a look [here](http://www.johnberardi.com/articles/nutrition/leaneating_1.htm) ([part 2](http://www.johnberardi.com/articles/nutrition/leaneating_2.htm)) for more info.

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**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\
**Post date:** [September 21, 2003, 12:44am UTC](https://boards.straightdope.com/t/do-i-really-need-3000-calories-a-day/202839/9 "2003-09-21T00:44:22Z")

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It’s odd how insanely inaccurate some of the daily caloric intake levels posted in magazines etc. are fo the average person.

For adult 30-50 year old males with average metabolisms, and relatively low activity levels, the daily calories needed to maintain a pound of weight varies from 10-13 calories food calories daily per pound of body weight. This is exactly the range I fall into and I have confirmed this calorie intake range empirically through 25 years of calorie counting and diets.

What a lot of people forget is the **huge** difference activity levels make in this calculation over time, and that the body speeds up the metabolism significantly 24/7 if someone is engaging in regular, semi-intensive exercise. This leads to overall daily caloric burn levels that are well higher than just those required for the exercise output, because of the overall higher metabolism effect. So you can have 200 lb men engaging in regular semi-intensive exercise that _can_ eat 3000 calories per day and not gain weight because their metabolisms have been turned up so that they require 15 caloires per lb per day, but if they stop exercising they will get as fat as hogs on this diet, because the metabolism drops back down like a shot once regular exercise ceases. This is one of the reasons athletes often balloon up once their playing days are over.

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**Author:** ![Dr\_Paprika](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dr_paprika/32/3042_2.png) [@Dr\_Paprika](https://boards.straightdope.com/u/Dr_Paprika)\
**Post date:** [September 21, 2003, 1:34am UTC](https://boards.straightdope.com/t/do-i-really-need-3000-calories-a-day/202839/10 "2003-09-21T01:34:02Z")

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3,000 calories is too mcuh for most sedentary people.

The Harris-Benedict Equations give the resting energy expenditure for people and are better validated.

Wt = weight in kg  
Ht = height in cm

Males: 66.47 + 13.75 \* Wt + 5.00 \* Ht - 6.78 \* Age = kCal/d  
Females: 655.09 + 9.56 \* Wt + 1.85 \* Ht - 4.68 \* Age = kCal/d

This needs to be multiplied from an activity factor of 1 for resting energy (completely sedentary) to 1.6 (very extreme athlete).

Hmm. I’m 31, 5’10 (178 cm) and 85 kg (187 lbs.)  
Without doing much, I burn 1915 Cal/d  
To burn 3000 calories, I’d need an activity level of 1.56.  
These days I’d be closer to 1.3 or so.

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**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\
**Post date:** [September 21, 2003, 2:06am UTC](https://boards.straightdope.com/t/do-i-really-need-3000-calories-a-day/202839/11 "2003-09-21T02:06:53Z")

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You can live long and healthy on 500-700 cals fewer than most calculations will show. 180 lb man can improve his life and life extesnsion by eating a nutrionally dense 1500 cal diet daily.

Look up Dr Walford of UCLA. At least he has real science backing up his claims.
