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A Calorie Is A Calorie
''"A calorie is a calorie"'' is an expression used to convey the concept that sources of dietary energy are interchangeable. This concept has been subject of debate since its emergence in the early 19th century. History In 1883, German nutritionist Max Rubner published what he called the "isodynamic law". The law claims that the basis of nutrition is the exchange of energy. In the early 1900s, Carl von Noorden applied isodynamic law to the study of obesity and developed two theories on what caused people to develop obesity. The first repeated Rubner's notion that "a calorie is a calorie". The second claimed that obesity is a consequence of how the body partitions calories for use or storage. These competing theories continue to be a source of dispute within nutrition and diet communities. Metabolism In thermodynamics, energy cannot be created or destroyed, only converted from one form to another. In nutrition, dietary energy refers to metabolizable energy, not gross energy. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Max Rubner
Max Rubner (2 June 1854, Munich27 April 1932, Berlin) was a German physiologist and hygienist. Academic career He studied at the University of Munich and worked as an assistant under Adolf von Baeyer and Carl von Voit (doctorate 1878). Later on, he taught as a professor at the University of Marburg (1885–1891), and in 1891 succeeded Robert Koch as a professor of hygiene at the University of Berlin. In 1909 he succeeded Theodor Wilhelm Engelmann as chair of physiology at Berlin. Rubner was co-founder of the '' Kaiser-Wilhelm Institut für Arbeitsphysiologie'', and became its director in 1913. With his assistant Gerhard Albrecht, Rubner set out to study labour not just as the expenditure of energy, but also the use of intellect. They rejected taylorism as being over-concerned with economic outputs, but rather advocated an approach which was more concerned with a biophysical approach to the elimination of fatigue. Contributions Rubner is remembered for his research in metab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Empty Calories
In human nutrition, empty calories are those calories found in foods and beverages (including alcohol) composed primarily or solely of calorie-rich macronutrients such as sugars and fats, but little or no micronutrients, fibre, or protein. Foods composed mostly of empty calories have low nutrient density, meaning few other nutrients relative to their energy content. Empty calories are more difficult to fit into a diet that is both balanced and within TDEE, and so readily create an unhealthy diet. Research The lack of complete nutrition found in high energy foods was first scientifically tested by French physiologist François Magendie, who experimented on dogs and described the process in his book ''Précis élémentaire de Physiologie''. He demonstrated that the eating of nothing but sugar, olive oil, or butter could be the cause of the death of his test animals within 30 to 40 days. Examples The following foods are often considered to contain mostly empty calories and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nutrition
Nutrition is the biochemistry, biochemical and physiology, physiological process by which an organism uses food and water to support its life. The intake of these substances provides organisms with nutrients (divided into Macronutrient, macro- and Micronutrient, micro-) which can be Metabolism, metabolized to create Food energy, energy and chemical structures; too much or too little of an essential nutrient can cause malnutrition. Nutritional science, the study of nutrition as a hard science, typically emphasizes human nutrition. The type of organism determines what nutrients it needs and how it obtains them. Organisms obtain nutrients by consuming organic matter, consuming inorganic matter, absorbing light, or some combination of these. Some can produce nutrients internally by consuming basic elements, while some must consume other organisms to obtain pre-existing nutrients. All forms of life require carbon, Biological thermodynamics, energy, and water as well as various other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bioavailability
In pharmacology, bioavailability is a subcategory of absorption and is the fraction (%) of an administered drug that reaches the systemic circulation. By definition, when a medication is administered intravenously, its bioavailability is 100%. However, when a medication is administered via routes other than intravenous, its bioavailability is lower due to intestinal epithelium absorption and first-pass metabolism. Thereby, mathematically, bioavailability equals the ratio of comparing the area under the plasma drug concentration curve versus time (AUC) for the extravascular formulation to the AUC for the intravascular formulation. AUC is used because AUC is proportional to the dose that has entered the systemic circulation. Bioavailability of a drug is an average value; to take population variability into account, deviation range is shown as ±. To ensure that the drug taker who has poor absorption is dosed appropriately, the bottom value of the deviation range is employed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sleep And Metabolism
Sleep is important in regulating metabolism. Mammalian sleep can be sub-divided into two distinct phases - REM (rapid eye movement) and non-REM (NREM) sleep. In humans and cats, NREM sleep has four stages, where the third and fourth stages are considered slow-wave sleep (SWS). SWS is considered deep sleep, when metabolism is least active. Metabolism involves two biochemical processes that occur in living organisms. The first is anabolism, which refers to the build up of molecules. The second is catabolism, the breakdown of molecules. These two processes work to regulate the amount of energy the body uses to maintain itself. During non-REM sleep, metabolic rate and brain temperature are lowered to deal with damages that may have occurred during time of wakefulness. Normal metabolism After eating, the pancreas releases insulin. Insulin signals muscle and fat cells to absorb glucose from food. As a result, blood glucose levels return to normal. Sleep loss and Type 2 diabetes In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientific Control
A scientific control is an experiment or observation designed to minimize the effects of variables other than the independent variable (i.e. confounding variables). This increases the reliability of the results, often through a comparison between control measurements and the other measurements. Scientific controls are a part of the scientific method. Controlled experiments Controls eliminate alternate explanations of experimental results, especially experimental errors and experimenter bias. Many controls are specific to the type of experiment being performed, as in the molecular markers used in SDS-PAGE experiments, and may simply have the purpose of ensuring that the equipment is working properly. The selection and use of proper controls to ensure that experimental results are valid (for example, absence of confounding variables) can be very difficult. Control measurements may also be used for other purposes: for example, a measurement of a microphone's background noise in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satiety Value
Satiety value is the degree at which food gives a human the feeling of satiety per calorie. The concept of the Satiety Value and Satiety Index was developed by Australians, Australian researcher and doctor, Susanna Holt. Highest satiety value is expected when the food that remains in the stomach for a longer period produces greatest functional activity of the organ. Limiting the food intake after reaching the satiety value helps reduce obesity problems. Foods with the most satiation per calorie are often: * high in certain Proteinase inhibitors in plants, proteinase inhibitors that suppress appetite - e.g. potatoes * high in protein leverage hypothesis, protein (which takes longer to digest than other energy sources) - e.g. meat * low in glycemic index (in which the carbohydrates take longer to digest) - e.g. oats * high in dietary fibre, fibre (which takes longer to digest than low fibre foods) - e.g. fruit * low in calories - e.g. vegetables * solid (which takes longer to digest t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exercise
Exercise or workout is physical activity that enhances or maintains fitness and overall health. It is performed for various reasons, including weight loss or maintenance, to aid growth and improve strength, develop muscles and the cardiovascular system, prevent injuries, hone athletic skills, improve health, or simply for enjoyment. Many people choose to exercise outdoors where they can congregate in groups, socialize, and improve well-being as well as mental health. In terms of health benefits, usually, 150 minutes of moderate-intensity exercise per week is recommended for reducing the risk of health problems. At the same time, even doing a small amount of exercise is healthier than doing none. Only doing an hour and a quarter (11 minutes/day) of exercise could reduce the risk of early death, cardiovascular disease, stroke, and cancer. Classification Physical exercises are generally grouped into three types, depending on the overall effect they have on the hum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metabolism
Metabolism (, from ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the conversion of food to building blocks of proteins, lipids, nucleic acids, and some carbohydrates; and the elimination of metabolic wastes. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their Structures#Biological, structures, and respond to their environments. The word ''metabolism'' can also refer to the sum of all chemical reactions that occur in living organisms, including digestion and the transportation of substances into and between different cells, in which case the above described set of reactions within the cells is called intermediary (or intermediate) metabolism. Metabolic reactions may be categorized as ''catabolic''—the ''breaking down'' of compounds (for example, of glucose to pyruvate by c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Management Of Obesity
Management of obesity can include lifestyle changes, medications, or surgery. Although many studies have sought effective interventions, there is currently no evidence-based, well-defined, and efficient intervention to prevent obesity. Treatment for obesity often consists of weight loss via healthy nutrition and increasing physical exercise. A 2007 review concluded that certain subgroups, such as those with type 2 diabetes and women who undergo weight loss, show long-term benefits in all-cause mortality, while long‐term outcomes for men are "not clear and need further investigation." The most effective treatment for obesity is bariatric surgery. Surgery for severe obesity is associated with long-term weight loss and decreased overall mortality. One study found a weight loss of between 14% and 25% (depending on the type of procedure performed) at 10 years, and a 29% reduction in all cause mortality when compared to standard weight loss measures. Another study also found red ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dieting
Dieting is the practice of eating food in a regulated way to decrease, maintain, or increase body weight, or to prevent and treat diseases such as diabetes and obesity. As weight loss depends on calorie intake, List of diets, different kinds of Calorie restriction, calorie-reduced diets, such as those emphasising particular macronutrients (low-fat diet, low-fat, low-carbohydrate diet, low-carbohydrate, etc.), have been shown to be no more effective than one another. As weight regain is common, diet success is best predicted by long-term adherence. Regardless, the outcome of a diet can vary widely depending on the individual. The first popular diet was "Banting", named after William Banting. In his 1863 pamphlet, ''Letter on Corpulence, Addressed to the Public'', he outlined the details of a particular low-carbohydrate, low-calorie diet that led to his own dramatic weight loss. Some guidelines recommend dieting to Weight loss, lose weight for people with weight-related health pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conservation Of Energy
The law of conservation of energy states that the total energy of an isolated system remains constant; it is said to be Conservation law, ''conserved'' over time. In the case of a Closed system#In thermodynamics, closed system, the principle says that the total amount of energy within the system can only be changed through energy entering or leaving the system. Energy can neither be created nor destroyed; rather, it can only be transformed or transferred from one form to another. For instance, chemical energy is Energy conversion, converted to kinetic energy when a stick of dynamite explodes. If one adds up all forms of energy that were released in the explosion, such as the kinetic energy and potential energy of the pieces, as well as heat and sound, one will get the exact decrease of chemical energy in the combustion of the dynamite. Classically, the conservation of energy was distinct from the conservation of mass. However, special relativity shows that mass is related to en ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
