There are tonnes of pre-built macro calculators online, which you're welcome to use a proxy for your caloric needs. But here is a little explanation as to what goes into those calculators.
STEP 1: YOUR ENERGY EXPENDITURE
How much energy are you using each day?
The first thing you'll need to do here is figure out how much fuel your body would use each day, if you were to do nothing but lay in bed. This is what we call your basal metabolic rate. Most calculations estimate this by taking into considerations things like; height, weight, gender, and body composition.
The most accurate formula for calculating this is the Katch-McArdle method. For this you'll need to know your body fat %, but if you don't have this number to hand you can use useful calculators like this to estimate it.
If you'd rather not use an estimate of your body fat % and you don't have reliable source for measuring this then you can use the Mifflin-St. Joer Equation to calculate you BMR instead. Both of these methods will give you a good ballpark figure to work from.
Next you'll need to take into account your activity level. We all know that more active people burn more calories so it's important we consider this when calculating our caloric needs. Often times people who don't consider this will find themselves way off base.
Below I've categorised different levels of activity and given each one an activity multiplier value. What you'll need to do at this stage is take your BMR that you calculated above and multiply it by the activity multiplier that corresponds most closely to your current activity or planned activity level:
Limited Activity (x1.3) – Desk job, mostly sedentary all day, and training is 3-5x/week for under an hour each time.
Low Activity (x1.6) – Some activity throughout your day but still minimal and you train 3-5x/week for around 60mins.
Moderate Activity (x1.8) – Moderately active throughout your day and you train 5-6x/week for 60-90mins.
High Activity (x2.0) – Active job or moving a lot throughout your day and you train 5-6x/week for 90mins or more.
Heavy Activity (x2.2) – You are very active outside of your training and you also perform 5-6 workouts for 90+ minutes, or even double days.
2. Now that we have a good estimate for you total daily energy expenditure (TDEE) we'll need to adjust this figure to account for your goal. The number you have right now is what we consider a maintenance value, so if you were to continue eating around this number of calories and being similarly active you should maintain your current bodyweight. But obviously there will be some people here who want to lose of gain body weight.
For this we'll need to reduce or increase calories relative to your goal. Below we've provided some guidance on how to manipulate your TDEE based on your goal.
Sustainable fat loss – Reduce total daily energy expenditure by 10%
Maintenance – Use total daily energy expenditure as calculated above
Lean Muscle Gain – Increase total daily energy expenditure by 10%
Rapid Weight/Muscle Gain – Increase total daily energy expenditure by 25%
STEP 2: YOUR MACROS
The next phase of further individualising your food intake is to look at your macronutrient distributions, effectively how much of your TDEE you consume in protein, fat and carbohydrates.
Your macronutrient needs will change over time depending on your activity level and goal, but it's also important to recognise that some of this may also be informed by how you FEEL with certain distributions. For example some people feel they have more consistent energy levels and are more satiated when they consume more fats relative to their carbohydrate consumption and vice versa. It's important that you recognise this and overtime decided on what works best for rather than blindly following a number for years.
1. DETERMINE YOUR PROTEIN NEEDS FIRST
When choosing your protein level we want to consider a few things, the most important of which are your current level of leanness and the type/amount of training you do. Protein is an essential macronutrient to prioritise for fat loss and muscle gain. Protein supports fat loss, muscle gain, satiety, and energy levels. With that said, more isn’t always better. When you are aiming to fix your caloric intake for weight loss, high protein means fewer grams of fat and carbs each day. Below we've provided some guidance as to how to decide on an appropriate level of protein. But FYI, most people will fall into the High or Moderate categories.
Very High (1.2-1.5g/lb of bodyweight) – Maintenance or muscle gain clients that are very lean, perform heavy resistance training, and already have a history of eating high protein diets.
High (1g/lb of bodyweight) – Maintenance, muscle gain or fat loss clients that are relatively lean; or if you’re not sure what your needs are, this is a good place to start.
Moderate (0.8g/lb of bodyweight) – Maintenance clients that have low or moderate activity, or fat loss clients that have slightly more fat to lose (>20/30% BF).
Low (0.5g/lb of bodyweight) – Fat loss clients that don’t train much and have a substantial amount of fat to lose (>30/40% BF).
1 gram of protein = 4 calories, so multiply your grams by 4 to see how much of your daily TDEE to eat in protein.
2. ESTABLISH YOUR CARBOHYDRATES
Carbohydrates are the one macronutrient that our bodies don’t have an essential need for. We can manufacture carbohydrates and derivatives as needed. However, in saying that, Carbs do have a profound impact on your hormones, energy, and body composition, and should be a macronutrient that you "play around with" in order to find optimal intakes and function for yourself.
Choosing what carb approach to take is very dependent on your goals and your past experience with higher or lower carb approaches.
Low – This sets your carbs at 20% of your TDEE. If you are aiming to lose fat either sustainably or with a challenge goal, this is generally a great option. If you are holding more body fat than you desire it is likely that your body will respond better with lower carbs.
Moderate – This sets your carbs at 33% (1/3) of your daily energy needs. If you aren’t sure where to start this can be a good first step. You can always change later when you get more clear on your goals and get the hang of counting your macros.
High – This sets your carbs at 50% of your daily energy needs. This is appropriate for high-performance athletes or individuals looking to build muscle.
As mentioned above some elements of carb intake will depend on activity level. If you're training for a marathon, team sports or muscle building, the likelihood is that carb intake will need to be at least moderate to high.
But there is another question to ask in order to further individualised your carbohydrate intake, and that is "what do you think is sustainable?". If you feel like fattier meals are more satiating and give you more consistent than lean into this and consider a lower carb intake. However, if with lower carb intakes you aren't able to resist cravings for more starchy foods then perhaps pick a higher carb intake, so you can plan for and consume higher quality carb sources, rather than reaching for what is available with your cravings get the better of you.
Some may also find that higher carb intakes increase your cravings for sugary foods. This is a good indication that perhaps a lower or more moderate carb intake is more appropriate as blood sugar regulation might be an issue.
The key with all this is controlled experimentation and finding the macronutrient numbers that make your eating a sustainable practice while you try to manipulate your body, health, and performance.
1 gram of carbohydrates = 4 calories, so multiply your grams by 4 to see how much of your daily TDEE to eat in carbs.
3. ESTABLISH FAT NEEDS LAST
General Guidelines for Fats; take care of your protein requirements first and then determine where you want to settle with your carbohydrates. After that, the remaining energy requirements you have, go towards fat. As an example, if your protein is 25% of your total calories, carbohydrates are 35%, then you would make your fat the remaining 40%.
Fat Adjustments; Fat is essential for great hormone function, tissue healing, and energy. Therefore, unlike carbohydrates there is a lower limit of fat that the body needs for basic function. Sometimes, when calculating out your calorie requirements and macro totals you can end up with a very low number for fat intake. In this case, if your fat totals come out to less than 50g then reduce your carbohydrate totals so that you can accommodate at least 50g of fat without exceeding your calorie intake.
For caloric calculations, 1 gram of fat = 9 calories.
STEP 3 – TRACK AND ADJUST (AKA LEARN AND REFINE)
When it comes to making adjustments to your diet based on your results it can be tempting to make daily or even weekly changes to try to elicit the response that you want. Our advice here, however, is to er on the side of caution. You really want to allow your body the time to adjust to a different caloric intake and activity level. This won't necessarily happen within a few days or a week. What we recommend is staying consistent with your plan for 14 days before you make any adjustments to what you're doing.
As mentioned in our "Keeping Track" article, we recommend weighing yourself daily and then taking a rolling average every 7 days. If your weekly average hasn't moved over a period of 1-2 weeks then we recommend making the following changes.
If your goal is to put on a little muscle and your weight has been stable during a 7-14 day period, then increase your calculated numbers or weekly averages by 10-20% and make those your target calories and macros for the coming weeks.
Maintain – if your goal is to simply improve your health, digestion, or under go some body recomposition, and weight gain or loss is not a priority, then keep your calculated numbers or weekly averages from the 7 day period the same if your weight remains stable. Dial back or ramp up if you are deviating from your baseline weight you want to keep.
Lose – If your goal is to lose body fat and your weight remains stable after the 7-14 day period, then reduce your calculated numbers or weekly averages by 10-15% from your previous set point.
Remember, when you first start a new diet all sorts of things can happen to your weight initially, but be patient. Wait for at least 14 days before you make any changes, then reflect on each weekly average and make adjustments accordingly.