Nutrition

Question

This piglix contains articles or sub-piglix about Nutrition

Answer 1

Dunn Human Nutrition Unit

MRC Mitochondrial Biology Unit

The MRC Mitochondrial Biology Unit (formerly the MRC Dunn Human Nutrition Unit) is an institution of the Medical Research Council based at the Addenbrooke’s Hospital / Cambridge Biomedical Campus site in Cambridge, England. The unit is a University of Cambridge partner institution concerned with the study of the , as this organelle has a varied and critical role in many aspects of eukaryotic metabolism and is implicated in a large number of metabolic, degenerative, and age-related human diseases.

The Unit was originally founded in 1927 using a donation from Sir William Dunn, who left £1 million to charity on his death in 1912. Part of this money was used to fund what was then called the Dunn Nutritional Laboratory, with its research supported by the MRC. The Unit was renamed in 2009 to the Mitochondrial Biology Unit under the directorship of Professor Sir John Walker to reflect its expertise in mitochondrial research. The current director of the Unit is Professor Massimo Zeviani.

The Unit has three major scientific aims:

The MBU is organised into eleven independent research groups and includes 30-40 graduate students who are members of the University of Cambridge:

The MBU is the home of several freely-accessible scientific web-resources:

MitoMiner - a mitochondrial proteomics database that provides information on cellular localisation, function and species & tissue specific expression

The Integrated Mitochondrial Protein Index (IMPI) - a list of all the genes and proteins that make up the mammalian mitochondrion

Professor Massimo Zeviani (2013 - )

Professor Sir John Walker (1998 - 2013)

...

Wikipedia

Answer 2

Ecotrophology

Ecotrophology is a branch of nutritional science concerned with everyday practice. It is mainly in Germany that it is seen as a separate branch of health care, and the word is rare outside Germany. Ecotrophologists are specialists in nutrition, household management and economics. This includes physiological, economic and technological principles of healthy nutrition and practical application. They work in many different fields: management of the above types of operations, development of new nutritional concepts in catering, quality control in food manufacturing and processing operations and research within the food industry. Due to the interdisciplinary nature of the training, ecotrophologists often take a coordinating role in Facility Management companies.

...

Wikipedia

Answer 3

Empty calorie

In human nutrition, the term empty calories applies to food such as solid fats or added sugars supplying food energy but little or no other nutrition. The USDA advises, "A small amount of empty calories is okay, but most people eat far more than is healthy."

The phrase is derived from nutrient density (proportion of nutrients in a food relative to its energy content), and calorie density (amount of energy relative to weight of the food). Thus empty calories are accompanied by no or few nutrients. Foods containing empty calories typically contain processed carbohydrates and ethanol (alcohol), and to some extent fats. Also known as a discretionary calorie, an empty calorie has the same energy content as any other calorie but lacks many accompanying nutrients such as vitamins, dietary minerals, antioxidants, amino acids, or dietary fiber. Although carbohydrates and fats are nutrients, they are typically ignored for this analysis, with the exception of essential fatty acids.

The error of considering energy foods as adequate nutrition was demonstrated by François Magendie by experiments on dogs and described in his Précis élementaire de Physiologie (1816). A book on sugar described the problem with empty calories as follows:

The following foods are often considered to contain mostly empty calories and may lead to weight gain:

All people require certain essential nutrients, but food energy intake must be balanced with activity to maintain a proper body weight. People who engage in heavy physical activity need food energy as fuel, which can be supplied by empty calories in addition to foods with essential nutrients. Sedentary individuals and those eating less to lose weight may suffer malnutrition if they eat food supplying empty calories but not enough nutrients.Dietitians and nutritionists prevent or treat illnesses by designing eating programs and recommending dietary modifications according to patient's needs. Eating a variety of nutritious foods every day protects against chronic illness and helps to maintain a healthy immune system.

...

Wikipedia

Answer 4

Essential amino acid

An essential amino acid, or indispensable amino acid, is an amino acid that cannot be synthesized de novo (from scratch) by the organism, and thus must be supplied in its diet. The nine amino acids humans cannot synthesize are phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine (i.e., F V T W M L I K H).

Six other amino acids are considered conditionally essential in the human diet, meaning their synthesis can be limited under special pathophysiological conditions, such as prematurity in the infant or individuals in severe catabolic distress. These six are arginine, cysteine, glycine, glutamine, proline, and tyrosine (i.e. R C G Q P Y). Five amino acids are dispensable in humans, meaning they can be synthesized in the body. These five are alanine, aspartic acid, asparagine, glutamic acid and serine (i.e., A D N E S).

(*) Essential only in certain cases.

(**) Pyrrolysine, sometimes considered "the 22nd amino acid", is not used by humans.

Eukaryotes can synthesize some of the amino acids from other substrates. Consequently, only a subset of the amino acids used in protein synthesis are essential nutrients.

Estimating the daily requirement for the indispensable amino acids has proven to be difficult; these numbers have undergone considerable revision over the last 20 years. The following table lists the WHO recommended daily amounts currently in use for essential amino acids in adult humans, together with their standard one-letter abbreviations. Food sources are identified based on the USDA National Nutrient Database Release.

...

Wikipedia

Answer 5

Energy homeostasis

In biology, energy homeostasis, or the homeostatic control of energy balance, is a biological process that involves the coordinated homeostatic regulation of food intake (energy inflow) and energy expenditure (energy outflow). The human brain, particularly the hypothalamus, plays a central role in regulating energy homeostasis and generating the sense of hunger by integrating a number of biochemical signals that transmit information about energy balance. Fifty percent of the energy from glucose metabolism is immediately converted to heat.

Energy homeostasis is an important aspect of bioenergetics.

In the US, biological energy is expressed using the energy unit Calorie with a capital C (i.e. a kilocalorie), which equals the energy needed to increase the temperature of 1 kilogram of water by 1 °C (about 4.18 kJ).

Energy balance, through biosynthetic reactions, can be measured with the following equation:

The first law of thermodynamics states that energy can be neither created nor destroyed. But energy can be converted from one form of energy to another. So, when a calorie of food energy is consumed, one of three particular effects occur within the body: a portion of that calorie may be stored as body fat, triglycerides, or glycogen, transferred to cells and converted to chemical energy in the form of adenosine triphosphate (ATP – a coenzyme) or related compounds, or dissipated as heat.

Energy intake is measured by the amount of calories consumed from food and fluids. Energy intake is modulated by hunger, which is primarily regulated by the hypothalamus, and choice, which is determined by the sets of brain structures that are responsible for stimulus control (i.e., operant conditioning and classical conditioning) and cognitive control of eating behavior. Hunger is regulated in part by the action of certain peptide hormones and neuropeptides (e.g., insulin, leptin, ghrelin, and neuropeptide Y, among others) in the hypothalamus.

...

Wikipedia

Answer 6

Ergosterol

Ergosterol

Ergosterol (ergosta-5,7,22-trien-3β-ol) is a sterol found in cell membranes of fungi and protozoa, serving many of the same functions that cholesterol serves in animal cells. Because many fungi and protozoa cannot survive without ergosterol, the enzymes that create it have become important targets for drug discovery. Ergosterol is a provitamin form of vitamin D₂; exposure to ultraviolet (UV) light causes a chemical reaction that produces vitamin D₂.

Ergosterol (ergosta-5,7,22-trien-3β-ol) is a sterol found in fungi, and named for ergot, the common name of members of the fungal genus Claviceps from which ergosterol was first isolated. Ergosterol is a component of yeast and other fungal cell membranes, serving many of the same functions that cholesterol serves in animal cells. Its specificity in higher fungi is thought to be related to the climatic instabilities (highly varying humidity and moisture conditions) encountered by these organisms in their typical ecological niches (plant and animal surfaces, soil). Thus, despite the added energy requirements of ergosterol synthesis (if compared to cholesterol), ergosterol is thought to have evolved as a nearly ubiquitous, evolutionarily advantageous fungal alternative to cholesterol.

Because ergosterol is present in cell membranes of fungi, yet absent in those of animals, it is a useful target for antifungal drugs. Ergosterol is also present in the cell membranes of some protists, such as trypanosomes. This is the basis for the use of some antifungals against West African sleeping sickness.

...

Wikipedia

Answer 7

Essential nutrient

An essential nutrient is a nutrient required for normal physiological function that cannot be synthesized by the body, and thus must be obtained from a dietary source. Apart from water, which is universally required for the maintenance of homeostasis, essential nutrients are indispensable for the metabolic processes of cells, as well as the proper physiological functions of tissues and organs. In the case of humans, there are nine amino acids, two fatty acids, thirteen vitamins and fifteen minerals that are considered essential nutrients. In addition, there are several molecules that are considered conditionally essential nutrients since they are indispensable in certain developmental and pathological states.

An essential amino acid is an amino acid that cannot be synthesized de novo (from scratch) by an organism, and therefore must be supplied in its diet. Out of the twenty amino acids, nine cannot be endogenously synthesized by humans: phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine.

Essential fatty acids (EFAs) are fatty acids that humans and other animals must ingest because the body requires them for good health but cannot synthesize them. Only two fatty acids are known to be essential for humans: alpha-linolenic acid (an omega-3 fatty acid) and linoleic acid (an omega-6 fatty acid).

...

Wikipedia

Answer 8

European Prospective Investigation into Cancer and Nutrition

The European Prospective Investigation into Cancer and Nutrition (EPIC) study is a Europe-wide prospective cohort study of the relationships between diet and cancer, as well as other chronic diseases, such as cardiovascular disease. With over half a million participants, it is the largest study of diet and disease to be undertaken.

EPIC is coordinated by the International Agency for Research on Cancer (IARC), part of the World Health Organization, and funded by the "Europe Against Cancer" programme of the European Commission as well as multiple nation-specific grants and charities.

521,457 healthy adults, mostly aged 35–70 years, were enrolled in 23 centres in ten European countries: Denmark (11%), France (14%), Germany (10%), Greece (5%), Italy (9%), The Netherlands (8%), Norway (7%), Spain (8%), Sweden (10%) and the United Kingdom (17%). One UK centre (Oxford) recruited 27,000 vegetarians and vegans; this subgroup forms the largest study of this dietary group. Recruitment to the study took place between 1993 and 1999, and follow up is planned for at least ten years, with repeat interview/questionnaires every three to five years. The main prospective data collected are standardised dietary questionnaires (self-administered or interview-based), seven-day food diaries, blood samples and anthropometric measurements, such as body mass index and waist-to-hip ratio. Additionally, the GenAir case-control study is studying the relationship of passive smoking and air pollution with cancers and respiratory diseases.

...

Wikipedia

Answer 9

European Society for Clinical Nutrition and Metabolism

The European Society for Clinical Nutrition and Metabolism (ESPEN) is an organization in the field of parenteral and enteral nutrition and promotes basic and clinical research, basic and advanced education, organization of consensus statements about clinical care and care quality control.

In 1979 an informal meeting laid the foundations of ESPEN, deciding to create a multidisciplinary society devoted to the study of metabolic problems associated with acute diseases and their nutritional implications and management. ESPEN was formally established in 1980.

Congress meetings are held every year in a different European city and gather over 3,000 participants from 82 different countries.

A bimonthly journal named Clinical Nutrition, which goes along with Clinical Nutrition Supplements and an electronic journal e-SPEN are the society's official publications, published by Elsevier.

European Parenteral and Enteral National Societies support ESPEN in the form of block members, e.g. the British, German, French, and Austrian societies.

Under the umbrella of ESPEN, many ongoing projects are supported by its members, such as NutritionDay, Home Artificial Nutrition, and Fight Against Malnutrition.

...

Wikipedia

Answer 10

Fat

Fat is one of the three main macronutrients, along with carbohydrate and protein. Fats, also known as triglycerides, are esters of three fatty acid chains and the alcohol glycerol.

The terms "oil", "fat", and "lipid" are often confused. "Oil" normally refers to a fat with short or unsaturated fatty acid chains that is liquid at room temperature, while "fat" may specifically refer to fats that are solids at room temperature. "Lipid" is the general term, as a lipid is not necessarily a triglyceride. Fats, like other lipids, are generally hydrophobic, and are soluble in organic solvents and insoluble in water.

Fat is an important foodstuff for many forms of life, and fats serve both structural and metabolic functions. They are a necessary part of the diet of most heterotrophs (including humans). Some fatty acids that are set free by the digestion of fats are called essential because they cannot be synthesized in the body from simpler constituents. There are two essential fatty acids (EFAs) in human nutrition: alpha-linolenic acid (an omega-3 fatty acid) and linoleic acid (an omega-6 fatty acid). Other lipids needed by the body can be synthesized from these and other fats. Fats and other lipids are broken down in the body by enzymes called lipases produced in the pancreas.

...

Wikipedia