Showing posts with label calories. Show all posts
Showing posts with label calories. Show all posts

Calorie Definition and Weight Loss

The food calorie is sometimes capitalized as Calorie to distinguish it from the chemistry calorie; however, this capitalization is rarely observed in practice.

The Nutrition Calorie

Nutritionists measure the energy content of food in "calories" (sometimes capitalized and abbreviated as Cal or sometimes C, or abbreviated kcal as if small calories were being used), where each food calorie represents 4,186 joules. This is equivalent to 1000 of the calories used in chemistry, and thus the food Calorie would be called a kilocalorie if small calories were being used. However, in chemistry calories have been deprecated as a scientific unit of measure in favor of joules, and therefore in common modern usage the word "calorie" usually refers to a food calorie.

This situation provides two ways of talking about the amount of calories in food which look quite different but that express the exact same amount of energy. One may say that dietary fat has nine kilocalories (kcal) per gram, while proteins and carbohydrates have four kcal per gram, or, one may say that fat has nine Calories per gram while carbohydrates and proteins have four Calories per gram.

The amount of food energy in a particular food is measured by completely burning the food in a bomb calorimeter, a method known as direct calorimetry. Dieticians recommend counting calories to avoid obesity. The government of the United Kingdom recommends consumption of no more than 2000 Calories (2000 kcal) by women each day and 2500 Calories (2500 kcal) by men each day.

The Physics and chemistry calorie

In physics or chemistry, a calorie (abbreviated cal) is a unit of energy that equals the amount of heat necessary to raise the temperature of one gram of water by 1 degree Celsius, at a pressure of 1 atm. This amount of heat depends somewhat on the initial temperature of the water, which results in various different units sharing the name of "calorie" but having slightly different energy values:

* the 15 °C calorie,
* the 4 °C calorie,da
* the mean 0 °C to 100 °C calorie,
* the International Steam Table calorie,
* the thermochemical calorie,

The slight variations in these units can be seen if you convert them to joules. For example, one 15 °C calorie is the amount of heat necessary to raise the temperature of 1 g of water from 14.5 °C to 15.5 °C. This is approximately equal to 4.1855 J or 3.968×10-3 Btu. The International Steam Table calorie is approximately equal to 4.1868 J and the thermochemical calorie 4.184 J.
Of these various units, what is most commonly meant by calorie in cntemporary English text is the 15 °C calorie.

The nutritional Calorie represents 1000 of these 15 °C calories. Since this could be a source of confusion and error, these units are now deprecated. The International System of Units (SI) unit for heat (and for all other forms of energy) is the joule (J), while the (obsolete) cgs (centimeter gram second system of units) system uses the erg (unit of energy and mechanical work in the centimeter-gram-second system) - From Wikipedia, the free encyclopedia.

Before start losing weight and counting calories you must first calculate the number of calories your body needs everyday, because this amount changes from person to person, depending on sex, age, weight, muscle content or height. Averages are situated around 2000 calories for women and 2500 for men. An easy, but not so accurate calculation is that for every 500 less than your normal amount of calories eaten every day you will lose up to one pound (453,6g) per week. 

Counting calories must be included as part of your diet, because when you loss weight is best to know how many calories your food has, and so ensuring that the amount of calories burned each day is more than the amount stored.  All nutritionists agree that a healthy low fat diet without counting calories could not exists, so take your time and solve that problem with various calorie calculators.

By knowing all the time the amount of calories consumed you can control how much you can eat and how it will affect your body. When dieting and counting the calories you can eat almost anything as long as you do not exceed the number of calories burned every day.

When you eat fewer calories, your body is forced to consume the fat stored to make up the deficit in your calorie count. Nutritionist’s advice is that you must combine psychical exercises with healthy eating in order to create some calorie deficit.

Resources:

The 2 Week Diet System - Click Here 

Menu Planning Central: Making life easier for busy individuals and families - like yours when it comes to meal planning. Click here for details

After A Diet, Why Does The Weight Come Back?

Before many Australians recently, a devastating story unfolded on a popular current affairs program. We watched with compassion as the fattest man in Australia told of his most recent, serious attempt to lose weight. Approximately 12 months earlier and weighing close to 300 kilos, he under went life threatening surgery to lose weight.

I doubt there would have been one person watching not moved by this man's depression and plight. Despite undergoing the surgery, today he could barely get through each day, both physically and mentally. He shared with us his sense of hopelessness and wanting to end it all.

It was not only his size that was causing his depression. He had to deal with a heart broken by disappointment.

You see, the surgery had been a success.

He soon lost well over 50 kilos post operation and he and his family rejoiced. But then the unthinkable happened.

The weight came back. Today he weighs well over 300 kilos - more than before the surgery.

This is an extreme case, but nonetheless raises a question that so many people continue to battle with.

After a diet, why does the weight come back so quickly?

To answer this we need to understand how much energy a body requires. For each pound you weigh, each day you need 12 calories to maintain your body weight. If you weigh 120 pounds you will need 120 x 12 calories, that is, 1440 calories per day to maintain that body weight. If you eat or drink more calories than your body requires, the excess energy is stored as fat. It takes 3,600 excess calories to make one pound of fat.

In this example, if your typical daily calorific intake is 2000 calories, in around 30 days you would put on between 4-5 pounds of fat!

Let's say, you then decide to go on a restrictive diet and halve your calorific consumption to 1,000 calories per day. You stay on this diet for around a month and lose 10 pounds and now weigh 110 pounds. You feel fantastic about losing the weight but can't keep up such a restrictive regime because you are irritable and have no energy.

So you go off your diet and go back to your usual routine of 2,000 calories a day. Remember you are lighter now and your body requires less energy to maintain its new weight. You would now require 110 x 12, that is, 1320 calories per day.

In this instance, by consuming 2000 calories daily, because you are lighter than before, you would put the weight back on in just 24-25 days!

If you want to keep the weight off you must develop a consistent change in eating habits to ensure you do not consume more than your body requires. You cannot continue to eat the same quantities and/or combinations of foods that caused you to be overweight in the first place. This will require developing an understanding of the nutritional content of food and raising your body's metabolism through increased muscle mass and exercise.

Resources:

The 2 Week Diet System - Click Here