If you want to figure out how many calories you need to eat per day there is wide variety of formulas and calculators that take into account your sex, age, current weight, activity level, and goals and will spit out a calorie count, but keep in mind these formulas, no matter what method or calculator, are all estimates. No one knows precisely how many calories you need, but you can experiment on yourself to figure it out.
LOSE WEIGHT IN A CALORIE DEFICIT
If you want to lose weight, then the first step is to create a calorie deficit. That means that you consume fewer calories then you burn.
You can do this by cutting 300-500 calories a day, or adding exercise or movement (like taking the stairs and walking the long way), in combination with an often overlooked but extremely effective long-term solution, building muscle with strength training. The more muscle you carry, the more calories you burn at rest—a higher metabolism. Strength training while you lose weight helps encourage that the weight you lose is fat, not muscle.
Be sure not to reduce calories too drastically, or your body can adapt to lower calorie intake, you lose muscle, so that you eventually won’t be able to eat more without gaining weight. About 300-500 calories under maintenance calories for a measured period is a good start for most healthy people.
HOW TO DETERMINE HOW MANY CALORIES TO EAT
ESTIMATE CALORIES WITH A CALCULATOR
The calculators can give you a starting point, and then you can adjust up or down based on your results. If you put in an online calorie estimator that you want to lose 50 pounds in one month (unrealistic and unhealthy), the calculator may tell you to eat 500 calories a day (also unrealistic and potentially harmful). The calculator doesn’t have a common sense detector; that’s your job.
ESTIMATE CALORIES WITH AN EASY FORMULA
If we’re estimating anyway, why not go with a more straightforward method? The simplest way if you want a starting calorie number is to use a calorie estimator like the one below. Again, nothing is going to give you an exact number, but if you want to get an idea of a starting point, this works as an uncomplicated alternative.
Multiply your body weight in pounds by your activity level:
Light exercise (30 minutes three times per week or less): x 10-12
Moderately active (30 minutes to an hour five times a week): x 12-14
Very active (one hour six to seven times a week or an active job): x 14-16
If you weigh 150 pounds with light exercise, you will estimate starting calories around 1500-1800 to potentially create a calorie deficit. You won’t know how many calories your body needs until you start experimenting. Figuring it out is the fun part!
TRACK YOUR WEEKLY CALORIES AND MAKE OUTCOME-BASED DECISIONS
Outcome-based decision making means you don’t rely on calculators, blog posts, even coaches to tell you what your body needs. You experiment with what you eat and make changes based on your outcome.
You can determine your calorie maintenance number by eating and exercising as usual for a week. Don’t try to eat better than usual, diet, or reduce anything at first. Track, measure and weigh everything you eat for a week. Don’t forget the creamer in your coffee, that 3 PM soda, the bites from your kid’s plate, and the chocolate from your co-worker’s desk, it all adds up.
The reason I ask you to measure and weigh (at first) is that a heaping spoon of peanut butter has a lot more calories than a measured tablespoon.
We, as humans, often underestimate the calories we eat and overestimate how many calories we are burning during exercise.
MAKE CALORIE ADJUSTMENTS AS NEEDED
Generally speaking, if your weight stays the same from one week to the next, that means you are in calorie maintenance. If you lose weight, you are in a calorie deficit, and if you gain weight, you are in a surplus. Of course, there are often other factors at play, including hormones, medications, stress, and medical issues—but I am speaking as a starting point for most healthy people in the general population—everyone is different.
Once you determine your maintenance calorie number, either slightly reduce calories or add exercise, (or a combination of both for best results) but again, extreme measures on either count will likely backfire.
Here’s a simplified way to determine what to do next:
If you don’t lose: slightly reduce calories (or be more consistent).
If you gain weight: slightly reduce calories (or be more consistent).
If you lose too quickly: slightly increase calories (or be more consistent) to avoid muscle loss.
The bottom line is that no one can tell you the amount of food you should consume. Experiment with the types and amounts of foods you eat, take note of how what you eat makes you feel, look, and perform and adjust as needed until you feel your best. It’s the only way to individualize your nutrition path.