The million dollar question: "How many calories do I need to eat each day?"
My honest answer is that I don't know exactly how many calories you'll need to reach your goals but I do have some very accurate ways of finding your starting point.
I take 3 steps in order to establish someone's calorie goal:
1. Determine their BMR (Basal Metabolic Rate)
2. Use a multiplier based on activity level to establish TDEE (Total Daily Energy Expenditure)
3. Subtract or add calories to TDEE based on their goal
Let's break this down, step by step.
So what the heck is your BMR?
Your BMR is the MINIMUM amount of calories your body requires to function... it supports things like digesting your food, brain function, pumping blood, breathing, etc. Basically all involuntary functions. Again, this is below your total intake as this is just enough calories to support being alive.
There are several ways to determine your BMR. You can calculate it using various equations:
The revised Harris-Benedict formula
The Mifflin-St. Jeer equation
The J.J. Cunningham equation
There are countless online calculators for all of them - a quick google search will do the trick.
The Harris-Benedict formula and the Mifflin-St. Jeer equation only factor bodyweight, gender and age - it does NOT account for the amount of muscle mass you have. The main issue with using these equations to determine your BMR is that your true BMR is heavily influenced by the amount of muscle you have.
Most athletes and leaner individuals would not get an accurate BMR using the above formulas since they fall outside of the norms of body fat and muscle mass from the Average Joe or Jane.
So if you're leaner (or an athlete) and you have an accurate measurement of your body composition (percentage of body fat), the J.J. Cunningham Equation will be far more accurate.
The most accurate way to determine your BMR is to get your body composition tested.. which is why I test all of my clients using our InBody. The InBody uses multifrequency bioelectrical impedance to accurately and independently measure the entire body, segment by segment.
Once you know your BMR, then we have to account for your daily activity level.
Your TDEE is the amount of calories you burn each day, living your life, doing your thang.
We need to determine a multiplier based on your activity level and exercise (if any) to establish your TDEE (Total Daily Energy Expenditure).
You can do this by multiplying your BMR by a factor that represents your ESTIMATED energy level, based on your activity.
Let's put this to practice.
I'll volunteer my numbers for the sake of science!
I currently weigh 160lbs of sweet, sweet awesomeness ;)
Using the Cunningham equation, I determined that my BMR is approximately 1750 calories.
Using a multiplier of "moderately active" I would then multiply 1750 x 1.55
1750 x 1.55= 2712 calories. 2712 is my TDEE (Total Daily Energy Expenditure)
I require (approximately) 2712 calories each day to maintain my body as is.
These are considered my maintenance calories. You read that correctly... it's a lot of food. Why? Because I have a lot of muscle ;)
Next up, we determine your goal.. and this is when you decide if you need to ADD calories to your TDEE or SUBTRACT calories from your TDEE to experience a change in your body composition.
If you're looking to lose body fat, then you need to be at a deficit (less than) from your TDEE.
If you're looking to gain muscle and grow, you need to be at a surplus (more than) from your TDEE.
A common pitfall people find themselves in when trying to lose body fat is subtracting far too many calories from their TDEE and adding more exercise to their routine.
It places them at too far of a deficit (the added activity you didn't account for requires more calories) and their fat loss quickly turns to muscle loss - NOT good.
Your muscle is precious - it's hard to earn and expensive (calorie wise) to maintain.
Think of your muscle as fire... the bigger your fire, the more calories your body will burn at rest. If you want to be lean (low body fat, not just skinny) and healthy, then you want to work towards building and maintaining your muscle mass.
So how many calories do you need to add or subtract to see a change?
Losing Body Fat:
Technically any calorie amount below your TDEE will put you at a deficit, causing you to lose weight. It just depends on how slow or fast you want to see progress - I always prefer slower, sustainable progress. And if you're going for fat loss (which is what I recommend unless you need to make weight as a competitive athlete), you don't want to move the scale too quickly.
The common recommendation is to reduce your TDEE by 500cals per day to lose weight. But I find that 500cals is aggressive for most people, especially if they're active. They end up losing muscle along with their body fat.
Start with a 200-350cal per day deficit. Apply those calories consistently each day for 10-14 days. Retest your body composition if possible or weigh yourself to keep track of a trend.
Adding Muscle Mass:
According to most research, you need to consume approximately 15% more calories than your TDEE, per day.
If you're considered a "hard-gainer" meaning you're naturally very lean and have trouble putting and keeping weight on, you may need to eat well above 15% of your TDEE. Start with a 25% increase, track your progress and add more calories if needed.
In addition to eating to grow, you need to provide the right stimulus to grow - you need to do challenging and effective resistance training 3-5 times per week.
You can only build muscle so quickly, so eating more than is needed to build muscle will just add fat to your frame. We want to minimize the fat gain so don't use your "bulking" season as excuse to eat with reckless abandon. You'll gain unnecessary body fat and risk having some serious health consequences by developing poor biomarkers.
The same concept of slow, sustainable progress applies to mass gaining.
You can find what acceptable progress looks like here for both fat loss and muscle development. Progress timelines vary from person to person.
Like I have mentioned several times, these are all estimations. A lot of them are very accurate but you won't truly know what works until you consistently apply these concepts for a few weeks and gauge your progress.
Also, any time you have a change to your lean body mass (an increase or decrease in muscle), your BMR will change and so will your daily calorie needs (TDEE).
If you increase your muscle mass, your BMR will increase. If you decrease your muscle mass, your BMR will decrease - requiring a greater calorie reduction to lose body fat.
This is all the more reason to track your body composition - the scale only tells a small portion of the story.
Further more, there is more to planning an ideal nutrition plan for your needs than just calculating your calories. You will also need to determine your macronutrient needs. But that is another lesson for another day.
Your BMR will help you with the foundation of your nutrition - the right amount of calories. This is the most important and influential factor when it comes to changing your body composition.
If you've found this helpful, please share with your friends, family and gym mates.
Don't get stuck working out really hard but not understanding how much food you need to eat in order to reach your goals.
If you need any help with this.. it's what we do! Click here to schedule a free intro. We can even test your body composition and determine your BMR.
-Nicole Race, owner Elevate St. Pete