How Do I Know How Much I Should Be Eating? (w/ dead-simple calculator)

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Ok, it’s time to get serious.  I talk a lot about eating “enough food” to support your activity level.  I realize that up until this point, that recommendation has remained relatively vague.  You’ve asked me, “How do I know how much I should be eating?” and I’m going to do my best to provide you with a succinct answer.  The problem with giving a one-size-fits-all recommendation, or setting up basic guidelines, is that they’re never right for everyone; each of us is a biochemically unique, adaptive organism living through its own personal challenges.  Even when a suggestion comes close, it needs to be tweaked as time wears on, or progression will wane.  Nevertheless, I’m going to do my best to explain what I mean by “enough food” and how to determine what that actually means.

Our new TDEE Calculator with activity multiplier

Here is the calculator for you guys to play with, but first, a few words of caution.  This isn’t a calorie counting exercise where you need to be all obsessive; running this calculator will simply enlighten you, show you what eating for performance looks like in a quantitative measurement, so you can make more educated decisions in regards to your food intake.  Before you start punching in your data, I want to ask you to look at this as a tool and nothing more.  Use this calculator as a means to establish a general idea of how much energy you expend during your average rest/training day, and go from there, always listening to your body and doing what feels right.

Without further ado, here is our new TDEE Calculator (remember almost everyone who Crossfit’s is considered “Very Active” and that is the calorie number we are looking at as your total)

Determining Activity Levels

Once you load the calculator, it should be pretty straight-forward.  You can ignore the bits about body fat percentage, waist circumference and such if you don’t have those data, but the “Activity” drown-down menu on the left beneath “Age” needs some special attention.  Half of knowing whether you’re eating enough comes from understanding how to define your level of activity.  The menu gives you several options; here’s how I’d suggest you match the categories available to your lifestyle:

  • Sedentary:  People who work a desk job and engage in very little (if any) structured exercise.  Chances are that if you’re reading this blog, this does not describe you, so you’ll probably avoid this option.
  • Very Active:  If you CrossFit or lift heavy a couple times a week, or if you work a physically demanding job, your activity level can probably be described as “very active”.
  • Extra Active:  For those of us who CrossFit 5-6 times a week.  Serious weightlifters and athletes, as well as folks who work jobs requiring hours of heavy llifting, fall into this category.

Again, because we’re all different and lead different lives, the TDEE (total daily energy expenditure) calculation that we arrive at is naught but a guideline; a person who lifts hay bales for 12 hours days will do well to classify their activity levels as “extra active” even if they’ve never touched a barbell in their lives.  A person who trains hard a few times a week but does little in the way of physical labor at work will err on the lower side of things.  Once you’ve got your numbers plugged in and your activity level selected, you’ll move onto the next page of the calculator: the macronutrient breakdown.

Macros:  What Are They and Why Are They Important?

Macronutrients are major components of your diet that are broken down into constituents to provide energy, build tissue and create hormones.  The ones we’re concerned with are protein (which provides 4 calories per gram), Carbs (4 calories per gram) and Fats (9 awesome calories per gram).  Just to clarify, micronutrients are vitamins that play an important role in how your body metabolizes the macronutrients that you make available.  A body without essential vitamins and minerals is like a car with a full tank of gas but no spark plugs.  This is why eating wholesome, nutrient-dense food is so important.

At the top left-hand corner, under “Presets”, you’re given several self-explanatory options.  I would recommend setting this to “Maintain” first and then to make adjustments with the sliders beneath the pie charts.  Here are some general guidelines for achieving different goals by manipulation your macronutrient ratios:

  • Improving performance/gaining muscle:  Increase your protein and fat on both days and increase your carbs on workout days.  Adding on an extra 3-500 calories for training days should help you put on some muscle and make some gains.  There are a lot of people out there looking to bulk up or get stronger with an all or nothing approach, but believe it or not, constant overeating may not be helping their progress.  Eating a little less carbohydrate on rest days can keep your body sensitive to insulin so that it can function properly when it needs the extra energy (around training).
  • Losing fat:  Simply eating at “Maintenance” calories and engaging in vigorous exercise a few times a week will help you lose body fat.  It’s important to eat when you’re active.  I write about it all the time because it’s true and I can’t stress it enough; you must eat enough or your workouts will suck and your long-term physique goals will be compromised.  To that end, a minor reduction in your carbohydrate intake on rest days that results in a 2-400 calorie deficit should do the trick and mobilize more fat, especially since you’re active.  Again, start small and work your way up.  Always pay attention to what your body’s trying to tell you.


A Real-World Example

I’m going to use Lindsey Valenzuela as my example, mostly because she is awesome.  Here are her stats that she tweeted the other day, with some minor adjustments to simplify the math.

  • Height:  5’6″
  • Weight:  150 pounds
  • Age:  26
  • Activity level:  Extra Active
  • BMR:  1572 kcal’s (basic calories you need to live)
  • Total Daily Energy Expenditure:  3000 (no wonder she’s so awesome)
  • Protein:  150g=600 calories from protein
  • Carbs:  300g (she is Lindsey after all)=1200 calories from carbs

That leaves 1200 calories to come from fat, so you divide by 9 which will leave us at 133.3 fat grams for the day.

Now let’s do a male example, but in this case he wants to put on 10lbs of muscle:

  • Height:  6’0″
  • Body fat %:  12%, 22.8lbs of fat
  • Lean Mass:  167lbs
  • Weight:  190
  • Age:  25
  • BMR:  2012 kcals
  •  TDEE:  3470

To get him there, we’re going to have him eat about 4,000 calories on training days, broken down into 187g of protein, 407g of carbohydrate and 181g of fat.  Now, let’s assume that several months have passed by and our male example’s training and diet were spot-on.  He gained 10lbs of muscle mass while adding only 2lbs of fat to his frame.  This is a great accomplishment, and his numbers look like this now:

  • Body fat %:  12%, 24.3lbs of fat
  • Lean Mass:  177.8lbs
  • Weight:  202lbs
  • BMR:  2115 kcals
  • TDEE:  3649

Compare the two sets of numbers:  A man at 190lbs and 202lbs, retaining the same body fat percentage burns only 100 more calories at rest, and only about 200 more throughout a day.  That equates to an extra hour of light activity or sleep…A sweet potato here or there.  First and foremost, it takes a lot of time, hard work and perseverance, but only a modest alteration of energy expenditure and intake to lose or gain weight.  The precise numbers are generally unimportant; as long as you’re within the ballpark everything is okay.  There are special circumstances where your unique biology and lifestyle require you to eat more or less but I’ll touch on that and explain why this is all so fuzzy in an upcoming article.  For now, what I want you to take away is this:  After you’re eating enough good food to end up in the general area according to the numbers, how you feel, how you perform, and how you look should always be the first indicators you assess when determining the effectiveness of your training and nutrition.


  • Everyone is unique, so there is no “one-size” diet prescription.  We all need different amounts of food based upon our height, weight, body composition and activity levels.
  • Basal Metabolic Rate (BMR) is the amount of calories you would theoretically spend at rest.
  • Total Daily Energy Expenditure (TDEE) is the amount of calories you burn in a day.  This is based upon your BMR and then multiplied by an activity multiplier.
  • We recommend eating at or just slightly below your estimated TDEE to ensure proper recovery from training
  • Using our calculator, you can determine your expenditure without doing any math.
  • Macronutrients (protein, fat, carbohydrate) provide the bulk of the energy in your diet.  By eating more or less of each, you can manipulate your weight, body composition and performance without restricting calories.
  • How you look, how you feel, and how you perform are more important than any number on a scale or a calculator.  

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13 Responses to How Do I Know How Much I Should Be Eating? (w/ dead-simple calculator)

  1. Brynda March 5, 2013 at 7:05 pm #

    So how do you use the calculator to adjust for wanting to LOSE fat? I didn’t see that feature, but I love the calculator. I do CrossFit 3-5 times/week (usually at least 4), but am WAY over the recommended BMI for my height/weight. Need to lose this fat and am having a really hard time. I’ve been CFitting since June 2012, steadily going 3-4 times a week since August. Eat mostly paleo, (probably 80/20), and haven’t seen the scale move. Now counting calories (keeping to 1200 net) daily and hoping it helps. Thanks for any info you can provide!

    • Paul Nobles March 6, 2013 at 8:10 am #

      you don’t. Here is why my what I suggest works and why you will never have to push the pedal harder for results ever again. Let’s say you are eating at TDEE, you figure out a good plan and you get good meals with good nutrients rolling. All of which is favorable as it relates to metabolism and that alone will start right sizing you immediately combined with Crossfit. Here is where we now pour gasoline and light the match. Once you are eating correctly everything changes, you become the best version of yourself and your work capacity immediately sky rockets. Things you couldn’t do before combined with moving properly become trivial. At this point you may actually want to up your calories even further but that depends on your goals. Do you see how eating actually creates the slight deficit you may or may not have needed all along?

    • Paul Nobles March 6, 2013 at 8:11 am #

      stay out of your own way and let the best version of you come out.

  2. Samara March 7, 2013 at 3:38 am #

    So, I eat a lot of fruit, and little carbs from rice, bread, wheat (I am gluten-free) but eat about 75 to 100 g of protein a day, about 13-20 g of fat per day, a lot of veggies, and about 3 pieces of fruit. (this is all natural, ‘good fats’ btw) I do Crossfit about 5 times a week plus extra cardio. I, like the others, am also just looking to lose that last belly chub! Is this enough??? :)

    • Paul Nobles March 7, 2013 at 5:30 am #

      this is from your comment max protein calories = 400g max fat calories = 180 calories unless you are eating about 1500 calories of carbs you are setting up a metabolic disaster for yourself and that is what is keeping your belly chub. Hope this helps.

      • Samara March 7, 2013 at 6:47 pm #

        OK so basically I should be eating at least 1500 calories of carbs is what you mean? Thank you so much!!

  3. Dustin willey March 8, 2013 at 7:05 pm #

    I am 233 six feet age 24. And have a very active life style. What would be my macros?

    • Dustin willey March 8, 2013 at 7:11 pm #

      I am looking to slim down.

    • Paul Nobles March 9, 2013 at 9:54 am #

      I am going to ask that everyone use the calculator but I will use you as one example. This is an average if you want to cycle buy the book and we can dial it in with the Q and A sessions. This is a suggestion and a place to start and make adjustments from there Protein/200g, Carbs/200g and I have your active calories as a Crossfitter as 3602 but I am going to add an a fudge factor and do your fats based off of 3300 calories. Fats are 190g. Do it that way and adjust up as your muscle mass rises. If you adjust down your body will retain fat. Your just going to have to trust me on this one. I know you are probably scared to up your calories because of all of the BS you have heard that counts as so much noise to me. Eat like a man and you will become the best version of yourself. Let me know how it goes.

  4. Ashley March 30, 2013 at 2:46 pm #

    I used the calculator with TDEE as I am looking to burn fat. 5’6″ 155 lbs places me at 155g P. Cross fit 3-4 times a week = moderately active. How do I chose my fat/carb in order to CBL and lose fat? I am thinking 50g C and 140 g F on rest days. Work out days being 100g C and 120g F. I went paleo, felt great with the whole anti inflammatory, but I gained 8 lbs in a mth and the scale wont budge. In addition I feel I am under eating on paleo. Not intentionally though. Like you’ve said in many of your posts, my performance hasn’t improved either. Wonder if I created a metabolic disaster lol. I have gotten slightly stronger but I think that’s because I was so weak to start. Do your seminars have question and answer sessions? There is so much great info on your blog!

    • Paul Nobles March 30, 2013 at 9:16 pm #

      Go 75g carbs on fat days and work up to 150g of carbs, that should get your metabolism rolling a bit. Are you a science lab member, that would be a great way to check in occasionally so we can dial it in for you.

      • Ashley March 31, 2013 at 3:24 am #

        Not yet, I have read through the page but wasn’t quite sure what it offered. It sounds like seminars on various health topics. I have seen “dial in” floating around the blog but wasn’t quite sure if it referred to attending seminars where members could listen to topics to dial in on their own health needs or if it literally meant dialing in to ask questions.

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