Calorie Calculator

What is a calorie?

From a scientific perspective, a calorie is a unit of energy and is the amount needed to raise the temperature of one kilogram of water one degree Celsius. Kilocalories, or kcal, is the term used for measuring food energy. One kcal equals 1,000 calories. Referring to a particular food or meal as having a certain number of calories dictates how much energy will be released by the nutrients in that food or full meal once digested and absorbed by the gastrointestinal tract.

All calories are not the same; some are quality calories, meaning they provide more nutrients per calorie than others. The quality of your food should always be considered for the goals of weight loss, weight gain, or weight maintenance. In other words, you should be trying to consume more energy-dense calories or calories that contain a lot of nutrients per calorie rather than empty calories.

For example, if choosing a 200-calorie snack, 200 calories from jellybeans are not the same as 200 calories from a banana. The banana provides electrolytes, fiber, and prebiotics, while the jellybeans provide just 200 calories of sugar. This dietary approach is crucial for weight maintenance. A healthy diet consisting of nutrient-dense foods  ensures that you can get the nutrients you need for optimal health without overconsuming calories. Eating plenty of vegetables, grains, and fruits—along with lean or plant-based protein sources—is one good way to achieve a healthy balanced diet

The nutrients that contribute to caloric intake include:

Carbohydrates: Sugars, starches, and non-energy-yielding nutrients such as fiber are all carbohydrates. Chemically, carbohydrates are composed of the elements carbon, oxygen, and hydrogen. For every gram of carbohydrates consumed, 4 kcals of energy become available.

Fats: Foods such as oils and butter are the most common fat sources, also referred to as lipids. Fat provides about 9 kcals per gram. Chemically, fat is made of carbon, oxygen, and hydrogen but has twice as many hydrogen atoms as carbohydrates. Because of these hydrogens, fat has more than twice the calories of carbohydrates. Therefore, foods with a much higher fat content provide more calories per gram than foods with a high carbohydrate content.

Protein: Protein is an energy-yielding nutrient like fat and carbohydrates, and it provides about 4 kcals per gram. What makes it unique is that it contains nitrogen. Even though protein can provide energy, its primary purpose is to support muscle growth, maintenance, and repair.

Alcohol: Alcohol by itself isn't considered part of the nutritional food groups. However, since alcohol does contain calories, it is best to include it here. Alcohol contains 7.1 calories per gram (7.1 kcal/gm), and the liquid calories can add up fast!

How many calories do I need?

How can a calorie calculator help me?

A calorie calculator will help you estimate the number of calories you need for daily maintenance, weight loss, or weight gain by considering your age, sex, height, weight, and activity level.

Counting calories  is a key component of self-monitoring and allows you to track your behaviors and progress in order to meet your health and fitness goals. Studies have shown that individuals who use digital tracking such as calorie calculators and counters as part of their weight-loss strategy tend to lose more weight than those who do not.

Self-monitoring is an essential component of any behavioral change program. It includes monitoring a behavior—such as food intake—and requires that you track your progress with some measurable outcome related to that behavior. Monitoring metrics such as body weight enables you to track your progress for the purpose of meeting your goals. Self-monitoring is also said to increase awareness, self-efficacy, and accountability, which are all considered important aspects of success in any behavioral change program.

A calorie calculator can also help you estimate how many calories you burn in a day or the number of calories your body burns when resting, known as your resting energy expenditure (REE). Your REE is determined by size, age, sex, and lean body mass. You can impact your REE by building and maintaining lean muscle through regular strength training and a healthy diet with adequate protein. Maintaining lean body mass is especially important as you age. The loss of lean body mass that is experienced during aging is the primary reason people say their metabolism slows as they age.

In addition, you burn calories through diet-induced thermogenesis, also called the thermic effect of food, which is the increase in metabolic rate measured after consuming a meal that can stay elevated for several hours. It includes the calories burned when digesting, absorbing, and metabolizing your food. Protein leads to the highest increase in your metabolic rate, followed by carbohydrates and fats. The exact number can vary among individuals, but for the typical diet, the estimate of the thermic effect is about 10 percent of calories consumed.

Physical activity is the biggest variable of the calories you burn in a day. The calories you burn through exercise—such as running, cycling, weightlifting, and other daily activities—is determined by the duration and intensity of the activity and body size. Exercise performed for longer periods and at a higher intensity level burns more calories. Additionally, a larger person can burn more calories for the same activity in comparison to a smaller person.

How do I use a calorie calculator for weight loss?

You can use the calorie calculator to help you lose weight  by first calculating your basal metabolic rate, then accounting for the calories you burn during exercise. Subtract 250-500 calories from that number to create your weight-loss goal. Many think that subtracting more calories will lead to even more weight loss; this may be true initially, but it will set you up for unhealthy results such as fatigue, nutrient deficiencies, and loss of lean body mass. Over-restricting your calories can lead to overconsumption later on. Additionally, the loss of lean body mass can eventually lead to a lowered metabolic rate. A slower long-term approach is more beneficial to achieving sustainable goals.

Most diets manipulate macronutrient distribution and claim that is the key to weight loss. However, there is no long-term ideal macronutrient distribution to achieve weight loss or maintenance if calories remain the same. In the short term (the first six months), high protein (less than 20 percent of calories), low carbohydrate diets (typically less than 120 grams of carbs per day) appear to result in greater than average weight loss. For example, a meta-analysis consisting of 32 studies tracked the same number of calories but some groups were given fat in place of carbohydrates. The studies found that energy expenditure and weight loss were higher in the groups that were on the lower-fat diet.

While these results may seem conflicting, they support the concept that no one macronutrient distribution can lead to weight loss that is correct for everyone. The diet and macronutrient distribution that works best for you—based on the quality of your food and how easy it is for you to sustain—will most likely be the diet to follow.

In addition to tracking your calorie intake, burning more calories than you consume is another important part of weight loss. The best way to burn more calories is to stay active and to make sure you maintain lean body mass, as muscle burns more calories even at rest than fat does. Your physical activity determines your daily calorie expenditure by the duration, intensity, and method of the exercise you perform. Some activities like cross-country skiing may burn more than other exercises such as walking, but intensity and duration are the keys. So, higher intensity, longer activities will burn more calories than less intense, shorter activities.

That said, performing high-intensity workouts isn't the only factor to weight loss. Using a weight loss app  to track calorie intake is an important step towards reaching your weight-loss goals. The key is to find a weight loss program  that works for you and stay consistent.