When most of us think of calories, we think of how fattening food is. In dietary terms, calories are the amount of energy that food provides.
If we consistently take in more energy than we need, we will gain weight. If we take in too little energy, we will lose weight, fat, and eventually muscle mass.

The definition of a calorie is the amount of energy needed to raise the temperature of 1 gram (g) of water through 1° Celsius.
How and when we eat can also make a difference, as the body uses energy differently throughout the day. Our body’s energy use will depend on how active we are, how efficiently our body uses energy and our age.

Fast facts on calorie intake and use

Recommended calorie intake depends on factors such as age, size, height, sex, lifestyle, and overall general health.
Recommended daily calorie intakes in the US are around 2,500 for men and 2,000 for women.
Eating a big breakfast could help with weight reduction and maintenance.

The brain uses around 20 percent of the energy used in the human body.
Factors affecting ideal calorific intake include age, bone density, and muscle-fat ratio.
A 500-calorie meal consisting of fruits and vegetables has more health benefits and will keep you feeling full for longer than a 500-calorie snack of pop

Burning calories

For the human body to remain alive, it needs energy.
Around 20 percent of the energy we take in is used for brain metabolism. Most of the rest is used in basal metabolism, the energy we need when in a resting state, for functions such as blood circulation, digestion, and breathing.

In a cold environment, we need more energy to maintain a constant body temperature, as our metabolism increases to produce more heat. In a warm environment, we need less energy.

We also need mechanical energy for our skeletal muscles, to maintain posture and move around.
Cellular respiration is the metabolic process by which cells get energy by reacting oxygen with glucose to produce carbon dioxide, water, and energy.

In other words, we need calories to fuel bodily functions, such as breathing and thinking, to maintain our posture, and to move around.
Here are some tips for burning energy and losing weight more effectively.

1. Eat breakfast: A protein and healthy fat breakfast can keep you full for longer and help prevent snacking during the day.
2. Eat regular meals: This can help you burn calories more effectively and helps prevent mindless snacking.
3. Remember your “five-a-day:” Fruits and vegetables can be a tasty snack and they can bulk out your meals. They are high in nutrients and fiber and low in calories and fat.
4. Eat slow-burning calories: High-fiber carbohydrates, such as legumes, and healthy fats, such as avocado, take longer to release energy, so you will not get hungry as quickly.
5. Exercise: This can help burn off extra calories, and it can make you feel good. A brisk daily walk is easy for most people to do and costs nothing. Challenge yourself with a pedometer. For people who use a wheelchair, there are exercises that can boost heart health and strength.
6. Drink water: It is healthful, has no calories, and can fill you up. Avoid alcohol and sodas as these can easily provide far too many calories. If you crave sweet drinks, choose unsweetened fruit juices, or better still, get a juice maker.
7. Eat more fiber: Fiber, found in fruits, vegetables, and whole grains, can help you feel full and encourage healthy digestion.
8. Use smaller plates: Research indicates that portion sizes have increased over the last 3 decades, and this may contribute to obesity. Using a smaller plate encourages smaller portions.
9. Slow down: Eat slowly and rest between courses or extra servings, as it can take 20 to 30 minutes for your body to realize it feels full.
10. Get enough sleep: Sleep loss affects metabolism, and it has been linked to weight gain.
11. Avoid eating 2 hours before bed: Eating within 2 hours of sleeping can interfere with sleep quality and promote weight gain.