Calorie And Weight Reduction |
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What is a Calorie?To define a calorie, we would say that it is the amount of energy needed to raise the temperature of a gram of water by 1 degree Centigrade. So what does that mean? Calories (or the energy) in foods are measured by a scientific method called direct calorimetry. Through this process, foods are actually burned in a chamber surrounded by water to determine how many calories are contained within that particular food. Calorie CountCalorie counts are given to foods to show how much food energy they supply. Calorie counts are provided to consumers on nutrition labels found on food products as well as in many books and resources. People often become obsessed with calorie counts in the foods they eat, even without understanding the role calories provide in maintaining life and health. Protein, carbohydrates, and fats (and alcohol) are the only substances that contribute calories or energy to our diets. Calories are terms that people are notorious for counting, tracking, eliminating, and discussing time and again because they are our most familiar measure of food. Calories are used to measure the amount of energy found in a food. The more calories a particular food has, the more energy it contains. Balancing Energy NeedsEnergy gives us the ability to move, be active, and do work. By learning to understand energy needs, you can learn more about managing weight. Your goal should be to know what type of energy goes in and how that energy is used up. The energy in foods is measured and counted in calories. When the calories going in balance energy going out, body weight is maintained. When the calories going in exceed energy going out, body weight can be gained. And when the calories going in are less than energy going out, body weight can be lost. Where Do Calorie Come FromDo Calories Come From?Three main groups of nutrients contribute calories to our diet: protein, carbohydrates, and fats. Protein and carbohydrates each contribute 4 calories per gram of food. Fat contributes 2.5 times as many calories, at 9 calories per gram of food. Dietary recommendations suggest reducing fat in the diet primarily because fats are so highly concentrated in calories. (Alcohol is not considered a nutrient, but it also contributes calories to the diet at 7 calories per gram.) Foods usually contain a combination of the calorie-contributing nutrients. These nutrients together contribute to that food's total caloric value. Let's look at several individual foods that you could opt for as a snack and see if that helps illustrate the contribution of calories from protein, carbohydrates, and fat. One ounce of cheese snack-crackers has 3 grams of protein, 19 grams of carbohydrate, and 7 grams of fat. To determine how many calories the crackers have from protein, multiply the amount of protein (3 grams) times 4 calories/gram, and you see that it has 12 calories from protein. To determine how many calories the crackers get from carbohydrates, take the amount of carbohydrates (19 grams) and multiply it by 4 calories/gram to get 76 calories from carbohydrates. And to determine how many calories the crackers get from fat, multiply the amount of fat (7 grams) times 9 calories/gram to get 63 calories from fat. The total calorie count for the crackers is 151 calories per serving. On the other hand, a 1/2 cup of low-fat cottage cheese has 12 grams of protein, 4 grams of carbohydrate, and 2 grams of fat. Multiply the 12 grams of protein times 4 calories/gram, and you see that the cottage cheese has 48 calories from protein. Multiply the 4 grams of carbohydrate times 4 calories/gram, and you see that it has 16 calories from carbohydrate. And multiply the 2 grams of fat times 9 calories/gram, and you get 18 calories from fat, for a total of 82 calories per serving. You can also determine further how determinations are made for total calories from fats and how fats can contribute excess calories to foods, thus adding excess calories to your diet. |
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Fat PercentageLook at the cheese crackers and cottage cheese again. Determine now what the percentage of fat is in a serving of these foods. To do so, divide the calories from fat by the total calories. So for the cheese crackers, divide 63 calories by 151 calories, and you see that 42 percent of the crackers' calories come from fat. For the cottage cheese, divide 18 calories by 82 calories, and you see that 21 percent of the calories come from fat. You can see from these examples that almost half of the calories come from fat in the cheese snack-crackers, whereas only a fifth of the calories come from fat in the cottage cheese. Although either of these foods would be an adequate snack choice, the cottage cheese contributes a greater amount of protein and less fat than the snack crackers. Recommendation For Daily Calorie IntakeAn overall healthy diet should include a combination of foods that contain protein, carbohydrates, and fats. The following breakdown demonstrates how each of these should contribute to the daily diet. By combining a variety of foods, you can meet this profile:
In actuality, the typical American diet is more like the following. 8: UND
Some improvements have been made in recent years, but further
changes are necessary to help improve the nutritional status of the
American population. Now let's examine the energy-producing nutrients
in more detail. Although it is not necessary to be totally focused on a specific
caloric requirement, it is helpful to understand approximately how many
calories it takes for your body to function. This will, in turn, help
you to estimate how much you need to reduce your intake of foods in
order to lose the weight you want. To get a general idea of the number of calories you need to lose
weight, you first need to estimate the number of calories you need to
maintain your body weight—your body weight at its current level. In
doing so you first must establish how many calories it takes to
maintain your normal body functions at rest. This is referred to as
your basal metabolic rate (BMR). Once you determine this number, then
you will be able to add additional calories to compensate for daily
activities and needs for basic body functions. I'll show you how. Start
with this equation: To determine your BMR, multiply your current weight by ten (for
women) or eleven (for men). A 150-pound woman has a BMR of 1,500. This
is the approximate amount of energy (calories) that this individual
needs at rest. (Although BMR is primarily calculated from kilogram
weight, this formula will still provide you with an accurate estimate
of your needs without converting weight to kilograms.) But because people do more than just rest, and
because our bodies. need energy (calories) to meet physical needs, we
must further determine our activity needs. To determine your activity needs do the following. So our lightly active 150-pound woman, with a BMR of 1,500, would
multiply 1,500 times 0.30. Her adjustment for activity needs would be
450. That mean she needs 1,500 calories just to get by without any
physical activity, but she needs another 450 calories on top of that to
accommodate her activity. Her total BMR would be 1,500 plus 450, or
1,950 calories. |
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