How Many Calories Should I Be Eating?

Updated Apr 29th, 2020 – Written by Craig Clarke

The first thing people usually ask is how many calories they should be eating. Well, that really depends on what your end goals are. Do you want to bulk up and put on as much mass as possible? Do you want to cut your fat and keep your muscle lean? Do you just want to lose weight? We’ll look at what methods you should be using in order to calculate your caloric intake, along with what you should actually be eating in a healthy diet.

This is an in-depth look at calorie counting and how it’s done. If you want a no-fuss, easy way to find your macros and calories needed – take a look at our keto calculator.

Let me firstly point out that all of the information here should be taken as general advice, and should never go against medical advice given by a physician. Depending on if your body has specific needs, this may not be the best nutrition advice to take – take it with a grain of salt, no pun intended!

There are a few basic terms that you will want to get familiarized with, and we’ll go over these with a brief explanation.

  • Basal Metabolic Rate [BMR] – The amount of calories you need to maintain your current body if you are completely sedentary.
  • Non-Exercise Associated Thermogenesis [NEAT] – The calories used from doing daily activities. This includes walking, showering, brushing your teeth, getting dressed, and unfortunately working.
  • Exercise Associated Thermogenesis [EAT] – The calories needed when you do planned exercise. Keep in mind that this usually isn’t a huge number unless you are punching out over 2 hours at the gym – running on the treadmill for 30 minutes isn’t exactly going to burn 5000 calories.
  • Thermic Effect of Feeding [TEF] – The calories used when eating and digesting your food. It is usually around 15% of your meal, which means it doesn’t matter if you eat 3 meals a day or 6 meals a day – it is still about 15% of your total caloric intake. Your TEF fluctuates depending on what your macronutrient intake and the fiber that is in the food. Protein has a higher TEF (up to 25%), carbs vary in TEF (5-15%), and fats have the lowest TEF (usually under 5%).
  • Total Energy Expenditure [TEE] – The total amount of calories you need on a day to day basis, and also the sum of BMR, NEAT, EAT and TEF. To make it simple, this is usually calculated with a general activity factor.

How Much Do You Actually Need?

How Much Do You Actually Need?

A multitude of factors are taken into account, including the heat your body uses and the amount of nitrogen & carbon dioxide your body gives off. C’mon, people don’t go around knowing this kind of information, and it’s usually negligent, so we rarely take these into account. Generally, we use:

  • Your age
  • Your sex (males generally need more calories than females)
  • Total weight and lean mass (the more lean mass, the more calories you need)
  • Diet (Your macronutrient intake)
  • Exercise (the more you exercise, the more calories you need)
  • Daily activity (if you work in construction, you will need more calories than someone in a desk job)
  • Physical state (are you injured, sick, or pregnant?)
  • Hormones

Estimating Your Requirements

Estimating Your Requirements

First, let’s calculate your BMR. There are 2 main formulas used today, and which one you used is dependent on you (and what statistics you have).

  • Mifflin-St. Jeor – This was based on studies done in the 1990’s, but is more realistic in today’s diet setting. It doesn’t take into account your body fat percentages, so it will overestimate in the overweight. That’s okay though!

MEN: BMR = [4.53 x weight in pounds] + [15.88 x height in inches] – [4.92 x age in years] + 5
WOMEN: BMR = [4.53 x weight in pounds] + [15.88 x height in inches] – [4.92 x age in years] – 161

  • Katch-McArdle – This is the most accurate formula for those of you who are relatively lean. If you have a good estimate of your body fat percentage, then use this.

LBM = [total weight in pounds x (100 – body fat percent)]/220.49
BMR = 370 + (21.6 x LBM)

Now that we have your BMR, we will need to factor in your total activity for the day. Multiply your BMR with the activity factor to give the TEE. That doesn’t mean how often you go to the gym, or for how long. You are accounting for everything you do during the day (active job vs. sedentary job). These are an estimation, but they are close enough to figure your needs out.

1.2 – Sedentary (If you have a desk job and don’t do very much exercise)
1.3 – 1.4 – Lightly Active (If you have light daily activity and do light exercise 1-3 days a week)
1.5 – 1.6 – Moderately Active (If you have reasonable daily activity and do moderate exercise 3-5 days a week)
1.7 – 1.8 – Very Active (If you have a physically demanding lifestyle and do hard exercise 6-7 days a week)
1.9 – 2.2 – Extremely Active (If you are an athlete in endurance training or have an extremely physical job with long hours)

Of course, nobody wants to do so much math, and there’s a much simpler and generalized formula you can use. Granted it’s not as accurate, but it gets the job done and can be used based on the goals you want to achieve. This formula uses a calorie per unit weight, and will calculate your TEE (no need to multiply with your activity factor).

12 – 14 calories per pound for normal and healthy individuals with a sedentary lifestyle doing little to no exercise.
14 – 16 calories per pound for those that exercise moderately 3 – 5 times a week with relatively active lifestyles.
16 – 18 calories per pound for those involved in vigorous exercise and physically demanding jobs.
18.5 – 22 calories per pound for those involved in heavy training (for example 15 or more hours per week).
22 or more calories per pound for those involved in extreme training (for example 20 or more hours a week).

Recalculating Based on Goals

Recalculating Based on Goals

Based on your TEE, you will need to readjust based on your current goals. If you want to lose weight, you will need to decrease the amount of calories you intake. If you want to gain mass, then you will need to increase the amount of calories you intake. Don’t just flop a number out and say “I’m going to take 300 calories off of my TEE”. You will want to do this based on a percentage value, because this will be different based on your size and caloric need.

  • To gain mass: Add 10-15% of your TEE to your TEE.
  • To lose weight: Subtract 10-15% of your TEE from your TEE.

Monitor your results over a steady period of 3-4 weeks and make adjustments from there. If you are gaining steadily or losing steadily, then you have hit your mark. Keep in mind that you won’t just shred off pounds in 1 week, and you won’t put on 10 pounds of muscle in a week either.

How Much Water Should You Drink?

How Much Water Should You Drink?

We left an elephant in the room and didn’t talk about water this whole time. Drink it! Water is essential to the body, as two-thirds of our weight is water. Without water, we would die in only a few days – if we starved ourselves we could last up to a month. For someone exercising, adequate hydration is just as important as adequate nutrition. Drink it when you are going to the bathroom, drink it when your bladder is cramping, drink it after you finish going to the bathroom, just drink it like it’s going out of fashion. Fill up a gallon jug and carry it around with you, so you know how much you are drinking. I recommend drinking at least a gallon of water a day.

Want to Lose Fat?

Your body needs a variety of nutrients in order to function healthily and meet your goals. Counting your calories is just not enough – you have to keep an eye on everything you put into your body. You can read up on how to establish a healthy diet in Macronutrients and the Ketogenic Diet.