A better understanding of calories can help us maintain a healthy weight throughout our lives.

A food or drink has calories. Some foods have more calories than others, and you can find calories listed on food items. Fresh fruit and vegetables have less calories. Some fruits and vegetables are high in calories and low in calories, while diet soda is not a good source of nutrition.

We need calories to stay warm, grow, work, and think. The energy gained from calories is needed to function well.

How many calories we need each day is dependent on a number of factors. We will be taking a look at the latest research and speaking to an expert to get a better understanding of calories.


The physics of calories

In the 19th century, the amount of heat needed to raise the temperature of a kilogram of water from 0 degrees to 1 degree Celsius was defined by the term calories. The scientists measured it as one kilo calories. A standard calories is made up of 1000 small calories.

The term kilo calories faded in the early 20th century when calories became scientifically defined. People in parts of Europe and Australia use the term kilojoules instead of calories. The number of calories is equal to the number of kilo-joules.

There are calories in each of the three main food groups. The calories per gram are listed.

  • Carbohydrate: 4 calories
  • Fat: 9 calories
  • Protein: 4 calories

Depending on the type of fiber, the calories in fiber can be different.

woman unpacking fresh organic vegetables

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How many calories should you eat every day?

Women should take in 1,600 to 2,000 calories a day, and men should take in between 2,000 and 3000 calories a day according to theDietary Guidelines for Americans. You will need less calories if you are less active. The number of calories a person needs can vary according to the guidelines. Depending on age, weight, sex, how much physical activity you do, and whether you are pregnant or breastfeeding

In order to get enough energy and nutrition, it's important to get enough calories from the right sources.

The average person's ratios may change for infants and young children who need more fat in their diet.

What are high-calorie foods?

Fried foods, fat meats, oils, butter, and candy are high in calories. Many high-cal foods are low in vitamins and minerals, but there are other high-cal foods that are healthy.

Almonds, walnuts, olive oil, and dark chocolate are healthy foods that are high in calories.

What are low calorie foods?

Fruits and vegetables are a good source of fiber. One cup of broccoli has 15 calories and an orange has 70 calories, according to the USDA Nutrition Database.

What are empty calories?

Foods with little or no nutrition are called empty calories. They have a lot of fat and sugar. An alcoholic drink is considered to be empty calories.

Some of the foods are empty calories.

  • Sugary drinks, including sodas, energy drinks, and fruit juices 
  • Cakes, cookies, donuts, muffins, and other carb-heavy desserts and snacks 
  • Chocolates, candies, and candy bars 
  • Processed meats, such as bacon and sausages 
  • Condiments and sauces, including ketchup and mayonnaise 
  • Fast foods and junk foods, including pizza, burgers, and French fries 
  • Solid fats, such as butter and shortening 

fried chicken and fries

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A balance needs to be struck between calories in and calories out. Excess calories are stored as body fat. Excess weight will be caused by us putting more calories in than we need.

If we eat too few calories or burn more energy through physical activity than we are consuming, we will end up with a deficit in calories. It is important to eat enough calories to have the energy your body needs for everyday activities as well as to stay healthy.

According to Snodgrass, there is a link between calories and weightloss. It is important to monitor your calories. 3,500 calories equates to one pound. If you want to lose a pound a week, you'll want to cut 500 calories from your diet.

Do you need to cut calories for weight loss?

There are other ways to lose weight that are more beneficial to your health than restricting calories.

Physical activity should be increased.

A regular exercise routine can help you burn calories and increase metabolism.

It's possible to cook more meals at home.

It's possible to cut back on junk food, ready meals and overprocessed foods. Lean meats include chicken and turkey, as well as a lot of fruit and vegetables.

It's better to get more sleep.

Poor quality sleep over a long period of time can make you want to eat more.

A person asleep

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What are low calorie diets?

A diet that focuses on calories is called a low-cal diet. If you have a history of diet and weight gain, it is a good idea to talk to a doctor before embarking on a low-cal diet.

According to the American Academy of Family Physicians, women should not eat less than 1200 calories a day, and men should not eat less than 1800 calories a day. People with diabetes or who are due to have surgery may benefit from a very low- calories diet. For a short time, calories are limited to around 800 to 1,000 a day.

It is difficult to sustain a low-calorie diet over a long period of time. They can be dangerous according to Dr Richard Allison. He says that a low-cal diet is not sustainable in the long term.

Allison suggests looking at nutrition density when choosing food.

When choosing between two food items with the same calories, you can provide your body with important vitamins and minerals. He says that another option may only provide calories from sugar and fat.

Allison says snacking is important in making sure you get the right nutrition for your body. It's important to look for products with a high amount of vitamins and minerals. A healthy snack should be at least 100-150 calories to prevent hunger and maintain satiety.

What's the best way to lose weight by counting calories?

A balance of calories in versus calories out is recommended by the CDC. You should keep a daily food diary and work out the calories you eat. Keep a note of how long you do physical activity.

It is possible to work out how many calories you are consuming.

  • Check the nutrition facts label on packaged foods for a calorie count on servings or portions. 
  • Find an online calculator to help you work out how many calories are in other foods you eat, such as fruit and veg. The USDA Nutrition Database (opens in new tab) has calorie counts on thousands of foods, and you can filter by portion size or other measurements. 
  • Find an exercise activity calculator that tells you how many calories you’re using during physical activity. The American Cancer Society (opens in new tab) has a quick and easy guide on lots of physical activities, from cleaning to playing tennis. 

If you see in your diary that you are taking in more calories than you can use, it is a good idea to look at your diet or physical activity to see if you can cut back on calories.

There are additional resources.