Friday 27 April 2012

Facts about calories

Some important facts about calories.

  • Calorie is a unit used to measure energy in food.
  • Our energy needs and energy expenditure are also measured in calories.
  • Obesity is the result of imbalance between calorie intake and expenditure.
  • 1000 calories are equal to one food calorie or one kilo-calorie.
  • A food calorie is also known as "Calorie" which is commonly used in dietetics.
  • Another measure that is commonly used in food labels is kilo joules.

What are calories?

Calories are a measure of energy, just as pounds is a measure of body weight. Different types of foods have varying amounts of energy. Similarly, energy needs and energy expenditure are deffer among individuals.

Understanding the facts about calories is important to maintain a healthy body weight. Because body weight is depends on calorie in and out of the body.

When we eat, we take energy from the food. It gives power to the body to function properly. Energy is essential for every single activity in the body including heart beat, breathing, and maintaining body temperature.

When we do physical activities such as walking, running, and gardening, we burn calories. the number of calories that are burnt depend on level of physical activity.

How many calories do we need?

The calorie requirement depends on many factors such as

  • Age of the person
  • Gender of the person
  • Body weight
  • Metabolic rate
  • Level of physical activity or exercise
Children need relatively more energy than adults. Similarly, energy requirement of men is generally more than that of women.

A fat person needs more calories to do a certain activity than a thin person.
For example;
An individual who has 200 pounds of body weight burns about 160 calories when he walk for 30 minutes in 3 miles per hour speed.

However, A person with 300 pounds body weight needs 235 calories to do the same activity.

The energy requirements are vary for different types of exercise.
For example;
Swimming for half an hour needs more calories than walking for 30 minutes.

On average, men need 2200 - 2700 calories per day, and women need 1800 - 2300 calories per day.
If you do more physical activity, you need more. If you live a sedentary life, you need less. 

Calories in food.

Majority of foods have calories, but the amount varies with types of foods.

Fat has high energy content. 1g of fat gives 9 calories. Therefore, it is obvious that fatty foods are loaded with calories. That is why fast food is bad for you.

1g of sugar (carbohydrates or carbs) will give you about four calories. Similarly, proteins provide same amount of energy.

The shocking fact that many people don't know is; alcohol gives more calories than sugar. 1g of alcohol will provide 7 calories.

What is the link between calories and obesity?

Basically energy imbalance is the primary cause of obesity and overweight.

When your energy intake is more than energy expenditure, you gain weight.
For example;
Assume that your energy intake is 3000 calories per day, and you burn 2500 calories a day. You consume 500 more calories in each day. These extra energy will be stored in your body as fat. As a result, you will put on weight.

About 3500 calories are equal to one pound of body weight. So, you will gain one pound in a week. That means more than 50 pounds in an year.