The diet industry is estimated to be a 40-60 billion dollar buisness. Despite all the diet strategies, weight management still comes down to the calories you take in versus those you burn off. Calories are the energy in food that feeds the constant demand to keep us functioning.
Regardless of the composition of the diet, thermodynamics dictate that a calorie is a calorie. A calorie is the amount of energy needed to raise the temperature of one kilogram of water by one degree Celsius. We calculate the available energy in food with the unit known as the food calorie or a kilocalorie. The food calorie is equal to 1000 calories thus a kilocalorie.
The 19th century American chemist Wilbur Olin Atwater constructed the Atwater-Rosa calorimeter which made it possible to calculate the caloric values of different foods. This 1896 system continues to be used today. Fats provide approximately 9 calories per gram, proteins and carbohydrates 4, alcohol 7 and fiber 2 calories per gram.
Atwater through his research demonstrated that whatever amount of consumed energy humans cannot use is left over and stored in the body, hence calories in = calories out. The calories being consumed and therefore taken in by your body are commonly referred to as 'calories in.' The calories we burn or what our bodies use for energy to do everything we need to do are commonly called 'calories out.' The issue for us is more than how many calories are in a particular food as read from the food label, but how many calories are actually derived personally from the particular foodstuff we digest.
Calories in = calories out is scientifically correct, but our calorie counts on nutrition labels do not take into account how we utilize and prepare the food. Nuts are one such food group for which evidence suggests that the Atwater factors may be poorly predictive. This is substantiated most recently in the American Journal of Clincal Nutrition. In this study, they looked at the energy value of almonds in the human diet and compared the measured energy value to the value calculated from the Atwater factors. The result was a 32% overestimation in their energy content. The label declares an energy content of 168-170 kcal/serving. The actual metabolizable energy content of the almonds was calculated, upon consumption 129 kcal per 1 oz serving.
Calories in food are calculated using historic weighted values and are an estimate. To accurately calculate what is entering someone's mouth unleashes mind boggling issues. Food is boiled, baked, grilled, microwaved to change its chemistry, and every food is digested by every human in its own way. Here are a few factors that effect the number of calories that are emitted from what we eat:
Billions of bacteria in our gut aid digestion and steal calories for themselves.
Some people have more bacteria in their gut and are more efficient at metabolizing food.
Proteins may require much more energy than fats to digest.
Some foods trigger the immune system to identify and deal with pathogens and this requires energy.
Cooking food increases the number of calories released during digestion.
Processed food requires less energy to consume and give us lots of energy for little work.
In general people with longer digestive tracts get more calories from their food.
People vary in the amounts enzymes they have ie. lactase enzyme.
Vegetables (especially raw), nuts and whole grains makes our digestive tract work for calories.
Dieting by reading food labels and counting the calories may be perplexing when the math doesn't add up to the weight you see on the scale. Sound food choices, moderation and physical activity along with restraint, persistence and determination will insure body weight goals. Labeling may fool you, but it is hard to fool yourself when you slip on your diet. Be strong and you will Get Strong.
The Pendulum Rack System used by the Michigan State Police