The following is a quick step by step guide to estimate how many calories you should eat to lose weight, which is a question I’m asked ALL the time. When someone says lose weight, I take it to mean “lose fat without losing muscle”, so the following takes that into account.
Here’s the basic equation of how to many calories you should eat to lose weight:
Seems simple enough, right? In order to solve this equation, we need to estimate your calorie burn and calorie deficit, which is Step 1 and Step 2.
Step 1 – Determine How Many Calories You Burn Per Day
While calculating your calorie burn can be tricky as I describe in detail in How to Calculate Your Calorie Burn, here’s a quick way to estimate your calorie burn:
The equations above assumes (1) you have a sedentary job, (2) you exercise moderately 3-5x per week and (3) your body fat is around 20%-25%. Don’t worry too much if you are not perfect with your estimate, just move to the next step.
Step 2 – Determine Your Calorie Deficit Per Day
Many people will choose a random daily calorie deficit say 500, or 1000 calories, but I strongly recommend NOT doing this, because you can easily put yourself in starvation mode. Instead, choose a calorie deficit percentage range of 15%-35% less calories than your total calorie burn.
For example, take a guy who is 190 pounds and wants an aggressive calorie deficit to lose weight. He would take his total daily burn of 2660 (190 x 14) and apply a 30% calorie deficit, which would be 800 calories (30% x 2,660). His target calorie intake is 1860 calories per day.
Now if you multiply your daily calorie deficit by 7, you get your total weekly calorie deficit. Since 1 pound of fat has 3500 calories, you can estimate how many pounds of fat you can lose each week (usually 1-2 pounds) based on your weekly calorie deficit.
Most health organizations recommend men don’t eat below 1600 calories and women don’t eat below 1200 calories, but keep in mind this is a law of averages approach. It really depends on how many calories you burn (see: How to Calculate Calorie Burn to estimate your BMR).
So how large of a deficit should you create? The leaner you are the lower your calorie deficit percentage should be (15-20%) whereas for people who have a lot of weight to lose, a 35% deficit could work well.
Step 3 – Track Your Progress
In order to validate that you have estimated your calorie burn properly and are eating the right calorie level, we need a way to track your progress. I’m a big fan of tracking body weight with Monday Morning Weigh Ins for all guys and some women (depends on if you are comfortable). If you have any issues with weighing yourself, then monitor how your clothes are fitting, or use a body fat caliper to measure body fat changes over time.
Weighing yourself is a proxy for body fat loss. If you are eating ample protein, moderate carbs, and strength training, it is highly likely if the number on the scale creeps downward that you are losing only fat while keeping your valuable muscle. Measuring your body fat percentage too frequently, such as once per week makes it difficult to discern changes.
So have we found the holy grail of losing fat? Simply choose a target calorie intake and voila, you get a lean body?
Losing fat is more complex than simply “calories in and calories out” and establishing a target calorie intake. For optimal fat loss, you should also consider the quality of calories, timing of calories, and breakdown of calories (protein, carbs, and fat). Finally, positive hormonal and metabolic changes from exercise can accelerate losing fat and have a HUGE impact.
In my experience, understanding how many calories you should eat by establishing a target intake, even just as a rough guide is crucial to successfully losing fat and maintaining body composition, and is actually more important than quality, timing, and breakdown of calories (research confirms this as well).
How Many Calories Should You Eat To Lose Weight?,