A Complete Guide to Calories

What is a Calorie?

Simply put, a calorie is a unit of food energy, a way to understand how much energy the proteins, carbs, and fats—and sugar and alcohol—in food give our bodies when we eat them.

What our body doesn’t use at first gets stored away as fat. “Calories are the usable energy units that your body uses to live and build muscle,” says Marjorie Nolan Cohn, R.D.N., owner of MNC Nutrition in Philadelphia.

“You need enough calories to get through your day with circulation, respiration, organ function, general activities of living and exercise, plus additional energy for your muscles to use to build up stronger and bigger after working out.”

Calculate Your Consumption

Knowing how many calories you are eating every day and the amount you need to go over or stay under, depending on your goals, is one of the key principles to building a bigger (or leaner) body.

One way is by estimating your total daily energy expenditure, or TDEE, which is the amount of calories your body burns in a 24-hour period. To get this number, you have to multiply your basal metabolic rate (BMR) by your activity amount.

To estimate your BMR, follow this formula: 66 + (13.7 x weight in kg) + (5 x height in cm) – (6.8 x age in years).

Once you have your BMR, multiply that by your activity factor, which, for our readers, should be between 1.55 for moderate exercise, three to five days a week, and 1.73 for heavy exercisers hitting the gym six to seven days a week.

“If you want to maintain your current weight, then you need to eat at least that amount of calories,” says Brigitte Zeitlin, R.D., C.D.N., owner of BZ Nutrition in New York City. “If you want to lose weight, then you need to make sure you eat slightly less than that. And if you want to gain weight, then you should eat slightly more than that.”

Not All Calories Are the Same

 Clean eating—meaning getting your food from whole foods—is what you’ll want to focus on for your calorie consumption, not quick fixes like the If It Fits Your Macros method to cut fat, a philosophy on eating that says you consume anything you please as long as you hit your caloric goals. Some see it as a valid way to get the body you want, but others claim it’s just an excuse to eat junk.

Proponents of IIFYM or similar diets aren’t acknowledging that, though technically a calorie is a calorie, what also comes along with food—vitamins, minerals, antioxidants—is equally important for building a fit, healthy body. Or, as Nancy Clark, R.D., C.S.S.D., sports nutrition counselor and author of Nancy Clark’s Sports Nutrition Guidebook, puts it: “All the calories in a can of cola come from sugar, but accompanied with no nutrients. All the calories in a glass of orange juice come from sugar, but those calories are accompanied by lots of vitamins and minerals—vitamin C, potassium, folic acid.” 

And if you are trying to cut fat, the fact that some calories are more satiating than others, like those from protein and fat, means that you will be better able to curb your appetite and cravings more successfully than with calories from sugar or carbs.

When Should You Consume Calories?

 “When it comes to workout performance, you definitely want to make sure you have enough fuel to get through a workout without feeling hungry or fatigued,” Zeitlin says.

Make sure you consume some food 30 minutes to an hour before working out. You want to allow yourself enough time to digest, or you risk feeling sick, says Zeitlin.

Go for a snack with about 200 to 250 calories—try some nut butter on toast or with a piece of fruit, such as an apple. To help build muscle after the workout, aim to get some food within 30 minutes post-workout, such as two hard-boiled or scrambled eggs with a whole-wheat English muffin. (A little butter won’t kill you, either.)

Should You Trust Nutrition Labels?

Mandated by the U.S. Food and Drug Administration (FDA) in 1990, nutrition labels are meant to provide you with a breakdown of the percentages that you should meet for one day of nutrients for a 2,000-calorie diet. But the FDA’s Nutrition Labeling Manual states that there is a “20% margin of allowance in labeled values” for most nutrients. That means if you’re looking at something with 500 calories, it could actually be 400 or 600 calories, a big difference if you’re trying to bulk up—or get lean, especially.

Though nutrition labels still offer guidelines that are close enough on average to keep your goals on track, don’t assume they’re the be-all and end-all on what exact amounts of nutrients and calories are in a food. And anyway, you should be eating mostly whole foods and limiting anything that comes in a package. 

Contrasting Calories

Below, we outline two 2,600-calorie days of eating to show you why a balanced diet, not just total calories, is important for keeping your physique in check.

The Best 13 Exercises for Torching Calories

To burn the most calories, you should focus on multijoint, or compound, exercises that utilize multiple muscle groups, according to Jim Smith, C.P.P.S., owner of Diesel Strength & Conditioning. Doing so increases the total caloric expenditure of the workout. 

Other strategies for maximizing calorie burning while working out include incorporating shorter rest periods, which increases the training density and efficiency of the workout, or, simply put, allows for more work in less time.  Smith also suggests including a variety of rep ranges and training loads for each exercise to help keep your body burning calories.  

He also recommends combining heavy training with low reps and moderate loads with high reps, along with doing ground-based exercises that include a standing component (e.g., Turkish getups), as these require you to put more effort into stabilizing and controlling your body throughout the movement.

Upper Body

• Dumbbell Bench Press
• Barbell Clean and Press
• Barbell Military Press
• Bentover Dumbbell Row
• Pullup
• Dip

Lower Body

• Back Squat
• Deadlift
• Prowler Push
• Kettlebell Swing
• Barbell Hip Thrust
• Dumbbell Lunge
• Bench Jump