Nutrition Nuts and Bolts

By Shelly Najjar

Calories: It’s on every food label, but what does it mean? What do they do? How many should we eat?

Definition

“A unit of measure used to express the amount of energy in a food”
Source: Nutritional Sciences: From Fundamentals to Food (2007) by McGuire and Beerman (commissioned link*)

In general science, a calorie (little “c”) is a very tiny measure of energy. To make this amount useful, in nutrition, we talk about Calorie (big “C”), kilocalories, kcals, or kcalories. These words all mean the same thing: 1000 calories (with the little “c”). The one on the food label is the big “C” version.

How many Calories should I eat?

Everybody needs calories to live. There are many equations you can use to find out how many Calories you should eat each day, but to make it easier, you can use a Calorie needs estimator that will calculate a range for you. The range will change based on many factors.

These include

• age
• sex
• height
• current weight
• goal weight
• activity level
• if you’re recovering from serious injury (like major burns, trauma, broken bones, etc)
• if you’re female, the program also should ask you if you’re pregnant or nursing

You can also get a free customized food plan from the USDA’s SuperTracker program, which includes estimations of how many Calorie, protein, fat, carbohydrates, and other nutrients you need each day.

Where do calories come from?

Calories are in almost every food we eat or drink, with the exception of plain water (and water flavored with zero-calorie flavorings). Some foods and drinks have more calories than others.

Foods are made up of the macronutrients called carbohydrates, fats, and proteins. Some foods and drinks also have alcohol in them. Here is the amount of Calories that each gram of those things provide:

• Carbohydrates (carbs) have 4 Calories (kcal) in 1 gram (g)
• Fats have 9 Calories (kcal) in 1 gram (g)
• Proteins have 4 Calories (kcal) in 1 gram (g)
• Alcohol has 7 Calories (kcal) in 1 gram (g)

A note on the alcohol calories: This is per gram of alcohol, not per gram of alcoholic beverage. If you drink mixed drinks with lots of sugar (a carbohydrate), you need to add the calories from each gram of sugar (even if it’s natural sugar from fruit juice) to figure out how many total calories the drink has.

How many calories are in… ?

If you want to find out how many calories a certain food has, you can check the Nutrition Facts label. If the food doesn’t have a label, you can use a variety of resources to find out how many calories a food has.

Here are some reputable places to look for calorie information:

• CalorieKing.com
• USDA’s SuperTracker and Food-a-Pedia
• WebMD’s Food-o-Meter

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You may also want to read…

• The Basics of the Nutrition Facts Panel
• Should you consider going gluten-free?
• What is a superfood?
• What are nutrients?

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Shelly Najjar, MPH, RDN is a Registered Dietitian Nutritionist and wellness coach at Confident Nutrition. You can find her on Facebook, Twitter (@ShellyNajjar), and LinkedIn.