Calories are the units of energy. Every food item has a specific energy that is metabolized by the body. Fat is a group of compounds that are insoluble in water and derived from food items such as ghee or oil. All fatty products contain calories but not all calories contain fat.
edit Difference between Burning Calories and Burning Fat
There is a difference between burning calories and burning fat. The main aim of exercising should be to burn body fat and not simply to burn calories. Light exercise burns calories from sugar and other carbohydrates, also called "energy calories". This leads to a loss of "water weight" and a decrease in metabolism. To target calories stored in body fat, there needs to be a high intensity exercise regime combined with weight training.
edit Exercising to burn fat
In order to lose fat, you need to keep some basic rules in mind. During aerobic exercises (cardio), the body goes through several stages before it reaches the point where it's burning fat. For the first 10-15 minutes of exercise, you burn only sugar calories (not derived from fat). In order for your body to utilize the energy stored in fat, you need to reach your target heart rate. This target heart rate is a range that depends on your age and fitness level (beginner, average or higher than average). It is the heart rate that ensures enough oxygen is available to burn body fat. Not only should the heart rate reach in this range to start burning fat, it should also be maintained during the length of the exercise so that calories from fat continue to be utilized.
edit Burning fat at rest
In order to burn fat even when you are not exercising, the rate of metabolism should be increased. This uses energy stored in fat, so all activities that increase metabolism are helpful in trying to reduce body fat. The best way to increase metabolism is anaerobic exercise such as weight training.
edit Food Groups
Most food groups provide calories, some more than others. Non-caloric food items include water, vitamins, tea leaves, coffee, spices and some other items. This means that consuming these products alone cannot be broken down to release energy in the body. Fat contains the maximum calories compared to other food groups, of 9 kcal per gram.
Fats constitute both fatty acids and glycerol. Examples of edible animal fat include lard, fish oil, and butter. Examples of edible plant fat include peanut oil, soya bean oil, sunflower oil, sesame oil, coconut and vegetable oil.
edit Nutrition and Health
Food provides the body with energy for various reactions and activities. The recommended calorie intake for men and women vary from 2000-2500 kcal/day. Children and older people require less calorie intake. The excess calories consumed are usually converted into fat and stored in the body as adipose tissue. A calorimeter can be used to measure the food energy or calories in a particular food item.
The intake of fat in the diet is necessary as it contains essential fatty acids required for the body. It also aids in the digestion and adsorption of important minerals. It not only stores excess energy in the body but is also essential to maintain a healthy skin, insulates the organs against shock and acts as a buffer against diseases. Fats can be categorized into saturated and unsaturated fats. Saturated fats are found in foods like oils, butter, beef, and dark chocolate and considered less desirable than unsaturated fatty acids which are found in foods like avocado, nuts, oils, and meats.
If the calorie intake exceeds the daily requirement level, and is not burned by exercise, it can result in weight gain and other health complications with the passage of time.
There are diseases associated with excess intake of fat in the body. Diets high in saturated fat have shown to be associated with an increased risk of heart disease and atherosclerosis.