Understanding Calories
Calories – such a familiar word! We hear the word “calories” all the time – from that food is so high calories to consume fewer calories to lose weight to figure out your calorie needs to exercise burns more calories. But, do you really understand the meaning behind the word? Well, read on! We’ll explore what calorie actually are, how to determine calorie needs and what foods are calorie dense.
What are calories?
Calories are a measurement of energy. When you eat food, your body uses energy from the calories provided by that food. The food you eat is digested and broken down into proteins, carbohydrates, and fats, which are absorbed by the body. Your body uses only as many calories as it needs to run metabolic processes such as maintaining your heartbeat, growing hair, healing broken bones, as well as fueling your level of activity. Anything more than that is stored as fat.
Carbohydrates, protein, fat and alcohol all contribute calories. Vitamins, minerals, fiber and water do not contain calories. You can figure out how many calories a food has by the grams of carbohydrates, protein and fat. Per gram, carbohydrates contain 4 calories, protein contains 4 calories and fat contains 9 calories. So, if a food has 50 grams carbohydrate, 10 grams protein and 5 grams fat, the food contains 285 calories.
How many calories do I need?
Three things influence the amount of calories you need: basal metabolic rate (BMR), thermic effect of food (energy used processing the food we eat) and physical activity.
BMR is a measure of the rate at which your body burns energy or calories at rest. BMR uses up to three-quarters of the calories you take in – you need this for basic life functions. The thermic effect of food uses about ten percent of the calories you take in. The major factor in burning more calories and increasing your metabolic rate is physical activity.
Many people think that thin people have a fast metabolism and overweight or obese people have a slow metabolism and many people use metabolism as their crutch. However, metabolism usually isn’t the culprit – it merely burns calories and determines your unique calorie needs. How much you eat (or don’t eat) on the other hand, plays a major role in determining weight gain (or loss).
Other factors, such as gender, age, body size, different life stages (such as growing teenagers and breastfeeding), metabolic conditions or diseases, genetics and the amount of muscle you have compared to body fat may also influence your how many calories you need. However, again, the factors mentioned above are the major determining factors.
Calculating Calorie Needs:
Formulas that estimate calorie needs take into account your BMR or the calories you burn at rest and your activity energy expenditure (AEE) or the calories your burn through exercise. Together, these make up your total energy expenditure (TEE).
To maintain your weight: Calorie intake = TEE
To lose weight: Calorie intake < TEE
To gain weight: Calorie intake >TEE
Two widely used and scientifically validated equations are the Harris-Benedict Formula and the Mifflin-St Jeor Formula. Let’s practice using the Mifflin-St. Jeor formula.
Step 1: Calculate your BMR
Males: 10 x weight (kg) + 6.25 x height (cm) – 5 x age (years) + 5 = BMR
Females: 10 x weigt (kg) + 6.25 x height (cm) – 5 x age (years) – 161 = BMR
Kg = weight in pounds divided by 2.2
Cm = height in inches x 2.54
Step 2: Find your activity factor and calculate your TEE
Activity Factors:
1. If you are sedentary (little or no exercise) : BMR x 1.2
2. If you are lightly active (light exercise/sports 1-3 days/week) : BMR x 1.375
3. If you are moderately active (moderate exercise/sports 3-5 days/week) : BMR x 1.55
4. If you are very active (hard exercise/sports 6-7 days a week) : BMR x 1.725
5. If you are extra active (very hard exercise/sports & physical job or 2x training) : BMR x 1.9
_______ X ________ = ____________
Your BMR Your AF Your TEE
Step 3: Determine your calorie goal
• To maintain weight: keep TEE calories the same
• To lose weight: subtract 500 calories from TEE or decrease calories by 15-20% below your maintenance level
• To gain weight: add 500 calories to TEE
Simple Equation for Women:
The following equation was designed for women and is quick to calculate. Use the same activity factors as above and please note that you may get a different calorie recommendation. Equations are estimates only.
1. Multiply your current weight in pounds (or goal weight if you are trying to lose weight) by 4.5.
2. Multiply height in inches by 15.88
3. Add the numbers in steps 1 and 2.
4. Multiply age by 5.
5. Subtract the number from step 4 from step 3.
6. Subtract 161 from step 5.
7. Multiply step 6 by one of the activity factors that best describes you.
8. Now you have your target daily calorie needs!
How can I increase my calorie needs?
Building lean muscle mass helps increase your daily calorie needs. Muscle burns more calories than fat, meaning you need more calories to maintain your weight, even at rest! Adding heart pumping, calorie burning exercise such as running, walking, swimming or biking also increases your daily calorie needs. So, don’t underestimate the value of weight training! Eating regular meals and fueling your body with enough calories each day will also help keep your BMR stable. Your body needs enough fuel everyday to function at its best.
How can I set a healthy weight goal?
When setting weight goals, be realistic. For example, if your weight goal is a number that you haven’t seen since high school, then it probably isn’t realistic. A more realistic approach is to start with 5-10% increments. So, if you are 180 pounds, a weight loss goal of 8-18 pounds is a great goal to start with. You can re-evaluate additional weight loss once you reach that goal. Losing 5-10% of your body weight can actually lead to big improvements in blood pressure, blood sugars and cholesterol. So, don’t underestimate the power of small losses!
To find a healthy weight range, you can use BMI (Body Mass Index). A BMI of 18.5-24.9 is considered healthy. Remember though, even if you don’t reach the “healthy range”, any weight loss makes a difference! Talk to your doctor or dietitian if you are concerned about your BMI. Below you will find a link for calculating BMR and BMI.
What are calorie dense foods?
Calorie dense foods are foods that contain a substantial amount of calories per serving, which is typically a small serving. They are usually low in nutrients, volume and water. Many processed foods and fast foods are calorie dense. One drawback - you don’t feel very full after eating a serving.
The goal is to limit calorie dense foods and include more low calorie density foods. Low calorie density foods contain fewer calories per serving, have a higher water content, and the serving size is usually larger. Fruits, vegetables and soups are all example of foods that usually have a low calorie density. They fill you up on fewer calories –a bonus for weight management! For example, compare 1.5 ounces of watermelon gummy candy (140 calories) to 1.5 ounces of fresh watermelon (9 calories). You would have to eat 17 ounces of fresh watermelon for the same amount of calories as the watermelon candy. And, that fresh watermelon will keep you satisfied a whole lot longer than the candy!
How can I decrease my calorie intake?
Cutting out for calorie dense foods that are low in nutrients along with watching portion sizes are excellent places to start. Start with small changes such as skipping the mayo on your sandwich, baking instead of frying, putting half of your or restaurant order in a to-go box or ordering low-fat salad dressing on the side. These are all simple changes that can up to a big calorie deficit.
Try tracking your meals using online meal trackers (or an old fashioned pen and paper) to identify where you can cut calories during the day. When cutting calories, it is recommended by health professionals that women do eat less than 1,200 calories per day and men 1,800 calories per day. So, if using one of the equations above puts you below 1,200 calories, for example – stick with 1,200 and increase your exercise.
Additional Resources:
www.bmi-calculator.net/bmr-calculator/
www.catchyourveggies.com
www.mypyramid.gov
www.sparkpeople.com
www.healthydiningfinder.com
Have a happy and healthy day!
Shauna Schultz, RD
Please note: The information in this article is not to be followed asmedical advice, diagnosis or treatment. Please consult with your physicianor primary health practitioner for information regarding your own personalhealth and necessary treatments.
