Breaking Down The Nutrition Panel: Calories

Woman using calculator to calculate bills at the table
Written by Jen Scheinman, MS, RDN

We’ve all heard the age-old adage “calories in vs. calories out.” Used in reference to weight, this phrase suggests that the key to weight management is balancing the calories you eat with the amount of calories you burn. Weight management is complex, and the “calories in vs. calories out” saying may oversimplify the process. However, knowing how many calories are in your foods is important for maintaining a healthy weight. 

While many of us may be familiar with this phrase, most of us don’t fully understand what a calorie is. That’s why this month’s Nutrient Profile is focused on calories. You’ll learn what a calorie is, where they come from in foods, how to know how many you need, and how to find them on the Nutrition Facts label.

What is a calorie?

When we talk about calories in food, we are describing how much energy that food will give us. Simply put, a calorie is a unit of energy. Our body uses the energy (calories) from the foods we eat and converts it to the energy that our body uses throughout the day. 

Technically, when we refer to “calories” in food, we are actually talking about kilocalories or Calories (with a capital C). The USDA defines a kilocalorie as “the amount of heat required to raise the temperature of 1 kilogram of water one degree Celsius”[1]. It’s not necessary to know the scientific details of what a calorie is, but understanding that it is a measurement of energy is important. 

Food calories come from carbohydrates, proteins, fats, and alcohol [2]. One gram of carbohydrate contributes four calories, as does one gram of protein3. One gram of fat contributes nine calories [3], and 1 gram of alcohol has seven calories [4]. The energy density of a particular food depends on how many grams of fat, carb, or protein (and alcohol when present) is in it. 

How many calories do I need?

There are a lot of factors that go into determining how many calories you require. Age, sex, height, and activity level comprise part of the formula that dictates how many calories you’ll burn on a given day. Whether you are trying to lose, gain or maintain your weight will also influence your caloric needs. 

The 2020 Dietary Guidelines for Americans recommend that sedentary adult women over age 19 consume between 1600-2000 calories a day depending on their age. Sedentary adult men need about  2000-2200[5],  depending on their age bracket. If you are an active adult, you will require more calories to support your activity levels. While the USDA uses a 2000 calorie diet as the benchmark to determine the % Daily Value for nutrients in a food, it’s important to remember that their calorie guidelines are general recommendations and not meant to be a specific target for you as an individual. 

There are a number of simple ways you can determine how many calories you need a day. Several calculators such as this Body Weight Planner are available online. You’ll enter your demographic information, including age and sex, your activity level, and if you are looking to change your current weight. It will then calculate how many calories you should eat a day.

Suppose you don’t want to use a calorie calculator but are trying to lose weight. In that case, a simple rule of thumb is to estimate how many calories you eat a day and create a daily 500 calorie deficit either from your diet, exercise, or a combination of both.   

Being shaky, weak, or irritable though may be a sign you need to eat and provide your body with energy. Eating slowly, taking breaks while you eat, and only eating till you’re comfortably full will keep you from overeating.[6]

To know how many calories you typically eat, you may want to track your meals. Using a smartphone app such as MyFitnessPal or Cronometer can be a great way to log how many calories you eat and burn through exercise daily. However, the Academy of Nutrition and Dietetics suggests that tracking is not for everyone and that tuning in to your body’s hunger and fullness clues may be the best way to determine how much you need to eat. 

The recommendation from the Academy of Nutrition and Dietetics is due to a number of concerns with calorie counting. First, many people don’t estimate their serving sizes correctly, leading to either an under or over-reporting of calories. Plus the amount of calories you burn is based on a number of factors including muscle mass, your body’s unique metabolism, and baseline energy expenditure. It is impossible to be precise in creating that “calories in vs. calories out” equation, even with a meticulous recording of what you eat. This can lead to frustration when the desired weight loss goals are not achieved. Furthermore, studies have found that relying on calorie tracking can lead to disordered eating and poor psychological well being in some individuals[7]. If you are someone you know is struggling with issues around food, eating, and body image it is important to get help. The National Eating Eating Disorder Association is a great resource to learn more about the signs of disordered eating and find help. 

oatmeal keto granola bar recipe

Decoding a nutrition label

Reading the Nutrient Facts panel is the best way to know how many calories are in a food. At the top of the label, you’ll find the number of calories in a serving of that food. The calories are totaled from those that come from carbs, protein, fat, and alcohol if applicable.


Remember that the number of calories listed is per serving, not per package. And a serving size may be a lot smaller than what you traditionally would eat[8]

keto granola bar nutrition

Healthy calories 

When it comes to calories, not all are created equal. For optimal health, you want to choose nutrient-dense foods, meaning they have a lot of nutrition without many calories. Fresh fruit and vegetables are great examples of nutrient-dense food. So are Munk Packs products.

Munk Packs Keto Granola Bars have 140 calories per bar, and their Keto Nut & Seed Bars have 140-150 calories per bar. Their Protein Cookies have 160-170 calories per serving or 320-340 calories per cookie. Made with whole food ingredients and lower in sugar than similar items, their products maximize nutrition and without compromising taste. 

peanut butter keto granola bar

What other questions do you have about calories, or the nutritional label overall? Let us know in the comments!


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