Don’t roll your eyes! The potion for losing that excess body fat is all around you. It covers two thirds of the planet. If you eat right and exercise at the intensity, frequency and duration proper for you, but still can’t get rid of a little paunch here and there, you’re probably just not drinking enough water.

No need to get defensive. You’re actually quite normal. Most people don’t drink enough water. Most people are also carrying around a few more pounds than they would be if they did drink enough water. If you can’t seem to get that weight off, try drowning your sorrows in nature’s magical weight-loss mineral. It works, and here’s why:

“What on Earth is ‘metabolism’, anyway?” People use the term all the time, but ask them what it means and you’ll get all kinds of answers. Merriam Webster defines it as, “The process by which a substance is handled in the body.” A little vague, but that’s really all it means.

There are many forms of metabolism going on in your body right now, but the one everyone is talking about it the metabolism of fat. This is actually something that the liver does when it converts stored fat to energy. The liver has other functions, but this is one of its main jobs.

Unfortunately, another of the liver’s duties is to pick up the slack for the kidneys, which need plenty of water to work properly. If the kidneys are water-deprived, the liver has to do their work along with its own, lowering its total productivity. It then can’t metabolize fat as quickly or efficiently as it could when the kidneys were pulling their own weight. If you allow this to happen, not only are you being unfair to your liver, but you’re also setting yourself up to store fat.

“I’ve tried it and I couldn’t stand it!” The problem is that, though many decide to increase their water intake, very few stick with it. It’s understandable. During the first few days of drinking more water than your body is accustomed to, you’re running to the bathroom constantly. This can be very discouraging, and it can certainly interfere with an otherwise normal day at work. It seems that the water is coming out just as fast as it’s going in, and many people decide that their new hydration habit is fruitless.

Do take heed, though. What is really happening is that your body is flushing itself of the water it has been storing throughout all those years of “survival mode”. It takes a while, but this is a beautiful thing happening to you. As you continue to give your body all the water it could ask for, it gets rid of what it doesn’t need. It gets rid of the water it was holding onto in your ankles and your hips and thighs, maybe even around your belly. You are excreting much more than you realize. Your body figures it doesn’t need to save these stores anymore; it’s trusting that the water will keep coming, and if it does, eventually, the flushing (of both the body and the potty) will cease, allowing the human to return to a normal life. It’s true. This is called the “breakthrough point.”

One recent finding, as irresponsible as it may be, that caffeine increases the body’s fat-burning potential has many people loading up on coffee before going to the gym. This finding may hold some degree of truth in it, but caffeine is, in essence, a diuretic, and diuretics dehydrate. Caffeine may increase the heart rate, causing a few more calories to be burned, but this is at the expense of the muscles, which need water to function properly. This isn’t doing your heart any favors, either. It’s already working hard enough during your workout. Never mix caffeine and exercise. In fact, your best bet is to stay away from caffeine all together. It’s a big bully that pushes your friend water out of your system.

Water is the best beauty treatment. You’ve heard this since high school, and it’s true. Water will do wonders for your looks! It flushes out impurities in your skin, leaving you with a clear, glowing complexion. It also makes your skin look younger. Skin that is becoming saggy, either due to aging or weight loss, plumps up very nicely when the skin cells are hydrated.

In addition, it improves muscle tone. You can lift weights until you’re blue in the face, but if your muscles are suffering from a drought, you won’t notice a pleasant difference in your appearance. Muscles that have all the water they need contract more easily, making your workout more effective and you’ll look much nicer than if you had flabby muscles under sagging skin.

“Eight glasses a day? Are you kidding?!” It’s really not that much. Eight 8-ounce glasses amount to about two quarts of water. This is okay for the average person, but if you’re overweight, you should drink another eight ounces for every 25 pounds of excess weight you carry. You should also up this if you live in a hot climate or exercise very intensely.

This water consumption should be spread out throughout the day. It’s not healthy at all to drink too much water at one time. Try to pick three or four times a day when you can have a big glass of water, and then sip in between. Don’t let yourself get thirsty. If you feel thirsty, you’re already becoming dehydrated. Drink when you’re not thirsty yet.

Do you think water is yucky? Drinking other fluids will certainly help hydrate your body, but the extra calories, sugar, additives and whatever else isn’t what you need. Try a slice of lemon or lime in the glass, or if you really think you hate water, try flavored water. Just make sure you read the labels. Remember that you’re going to be consuming a lot of this fluid.

It’s probably a good idea to stop drinking water a good three hours before you go to bed. You know why.

“How cold should it be?” This is debatable. Most experts lean toward cold water, because the stomach absorbs it more quickly. There is also some evidence that cold water might enhance fat burning.

On the other hand, warmer water is easier to drink in large quantities, and you might drink more of it without even realizing it. Do whatever suits you, here. Just drink it!

When you drink all the water you need, you will very quickly notice a decrease in your appetite, possibly even on the first day! If you’re serious about becoming leaner and healthier, drinking water is an absolute must. If you’re doing everything else right and still not seeing results, this might just what’s missing.

Chemically, carbohydrates are simple organic compounds that are aldehydes or ketones with many hydroxyl groups added, usually one on each carbon atom that is not part of the aldehyde or ketone functional group. The basic carbohydrate units are called monosaccharides, such as glucose, galactose, and fructose. The general stoichiometric formula of an unmodified monosaccharide is (C·H₂O) _n, where n is any number of three or greater; however, the use of this word does not follow this exact definition and many molecules with formulae that differ slightly from this are still called carbohydrates, and others that possess formulae agreeing with this general rule are not called carbohydrates (eg formaldehyde).

Monosaccharides can be linked together into polysaccharides in almost limitless ways. Many carbohydrates contain one or more modified monosaccharide units that have had one or more groups replaced or removed. For example, deoxyribose, a component of DNA, is a modified version of ribose; chitin is composed of repeating units of N-acetylglucosamine, a nitrogen-containing form of glucose. The names of carbohydrates often end in the suffix (ose).  

D-glucose is an aldohexose with the formula (C·H₂O) ₆. The red atoms highlight the aldehyde group, and the blue atoms highlight the asymmetric center furthest from the aldehyde; because this -OH is on the right of the Fischer projection, this is a D sugar.

Monosaccharides are the simplest carbohydrates in that they cannot be hydrolyzed to smaller carbohydrates. The general chemical formula of an unmodified monosaccharide is (C•H₂O)_n, where n is any number of three or greater.

 Classification of monosaccharides

The A and β anomers of glucose. Note the position of the anomeric carbon (red or green) relative to the CH₂OH group bound to carbon 5: they are either on the opposite sides (α), or the same side (β).

Monosaccharides are classified according to three different characteristics: the placement of its carbonyl group, the number of carbon atoms it contains, and its chiral handedness. If the carbonyl group is an aldehyde, the monosaccharide is an aldose; if the carbonyl group is a ketone, the monosaccharide is a ketose. Monosaccharides with three carbon atoms are called trioses, those with four are called tetroses, five are called pentoses, and six are hexoses, and so on. These two systems of classification are often combined. For example, glucose is an aldohexose (a six-carbon aldehyde), ribose is an aldopentose (a five-carbon aldehyde), and fructose is a ketohexose (a six-carbon ketone).

Each carbon atom bearing a hydroxyl group (-OH), with the exception of the first and last carbons, are asymmetric, making them stereocenters with two possible configurations each (R or S). Because of this asymmetry, a number of isomers may exist for any given monosaccharide formula. The aldohexose D-glucose, for example, has the formula (C·H₂O)₆, of which all but two of its six carbons atoms are stereogenic, making D-glucose one of 2⁴ = 16 possible stereoisomers. In the case of glyceraldehyde, an aldotriose, there is one pair of possible stereoisomers, which are enantiomers and epimers. 1,3-dihydroxyacetone, the ketose corresponding to the aldose glyceraldehye, is a symmetric molecule with no stereocenters). The assignment of D or L is made according to the orientation of the asymmetric carbon furthest from the carbonyl group: in a standard Fischer projection if the hydroxyl group is on the right the molecule is a D sugar, otherwise it is an L sugar. Because D sugars are biologically far more common, the D is often omitted.

 Conformation

Glucose can exist in both a straight-chain and ring form.

The aldehyde or ketone group of a straight-chain monosaccharide will react reversibly with a hydroxyl group on a different carbon atom to form a hemiacetal or hemiketal, forming a heterocyclic ring with an oxygen bridge between two carbon atoms. Rings with five and six atoms are called furanose and pyranose forms, respectively, and exist in equilibrium with the straight-chain form.

During the conversion from straight-chain form to cyclic form, the carbon atom containing the carbonyl oxygen, called the anomeric carbon, becomes a chiral center with two possible configurations: the oxygen atom may take a position either above or below the plane of the ring. The resulting possible pair of stereoisomers are called anomers. In the α anomer, the -OH substituent on the anomeric carbon rests on the opposite side (Trans) of the ring from the CH₂OH side branch. The alternative form, in which the CH₂OH substituent and the anomeric hydroxyl are on the same side (cis) of the plane of the ring, is called the β anomer. Because the ring and straight-chain forms readily interconvert, both anomers exist in equilibrium.

 Use in living organisms

Monosaccharides are the major source of fuel for metabolism, being used both as an energy source (glucose being the most important in nature) and in biosynthesis. When monosaccharides are not needed by cells they are quickly converted into another form, such as polysaccharides.

 Disaccharides

Sucrose, also known as table sugar, is a common disaccharide. It is composed of two monosaccharides: D-glucose (left) and D-fructose (right).

Two joined monosaccharides are called disaccharides and represent the simplest polysaccharides. Examples include sucrose and lactose. They are composed of two monosaccharide units bound together by a covalent bond known as a glycosidic linkage formed via a dehydration reaction, resulting in the loss of a hydrogen atom from one monosaccharide and a hydroxyl group from the other. The formula of unmodified disaccharides is C₁₂H₂₂O₁₁. Although there are numerous kinds of disaccharides, a handful of disaccharides are particularly notable.

Sucrose, pictured to the right, is the most abundant disaccharide and the main form in which carbohydrates are transported in plants. It is composed of one D-glucose molecule and one D-fructose molecule. The systematic name for sucrose, O-α-D-glucopyranosyl-(1→2)-D-fructofuranoside, indicates four things:

• Its monosaccharides: glucose and fructose
• Their ring types: glucose is a pyranose, and fructose is a furanose
• How they are linked together: the oxygen on carbon number 1 (C1) of α-D-glucose is linked to the C2 of D-fructose.
• The -oside suffix indicates that the anomeric carbon of both monosaccharides participates in the glycosidic bond.

Lactose, a disaccharide composed of one D-galactose molecule and one D-glucose molecule, occurs naturally in milk. The systematic name for lactose is O-β-D-galactopyranosyl-(1→4)-D-glucopyranose. Other notable disaccharides include maltose (two D-glucoses linked α-1,4) and cellobiose (two D-glucoses linked β-1,4).

 Oligosaccharides and polysaccharides

Amylose is a linear polymer of glucose mainly linked with α(1→4) bonds. It can be made of several thousands of glucose units. It is one of the two components of starch, the other being amylopectin.

Oligosaccharides and polysaccharides are composed of longer chains of monosaccharide units bound together by glycosidic bonds. The distinction between the two is based upon the number of monosaccharide units present in the chain. Oligosaccharides typically contain between two and nine monosaccharide units, and polysaccharides contain greater than ten monosaccharide units. Definitions of how large a carbohydrate must be to fall into each category vary according to personal opinion. Examples of oligosaccharides include the disaccharides mentioned above, the trisaccharide raffinose and the tetrasaccharide stachyose.

Oligosaccharides are found as a common form of protein posttranslational modification. Such posttranslational modifications include the Lewis and ABO oligosaccharides responsible for blood group incompatibilities, the alpha-Gal epitope responsible for hyper acute rejection in xenotransplanation, and O-GlcNAc modifications.

Polysaccharides represent an important class of biological polymers. Their function in living organisms is usually either structure or storage related. Starch is used as a storage polysaccharide in plants, being found in the form of both amylose and the branched amylopectin. In animals, the structurally similar but more densely branched glycogen is used instead. Glycogen’s properties allow it to be metabolized more quickly, which suits the active lives of locomotive animals.

Cellulose and chitin are examples of structural polysaccharides. Cellulose is used in the cell walls of plants and other organisms, and is claimed to be the most abundant organic molecule on earth. It has a variety of uses including in the paper and textile industry and as a feedstock for the production of rayon (in the viscose process), cellulose acetate, celluloid and nitrocellulose. Chitin has a similar structure to cellulose but has nitrogen containing side branches, increasing its strength. It is found in arthropod exoskeletons and in the cell walls of some fungi. It has a variety of uses, for example in surgical threads.

Other polysaccharides include callose or laminarin, xylan, mannan, fucoidan, and galactomannan.

 Nutrition

Grain products: rich sources of complex and simple carbohydrates

Carbohydrates require less water to digest than proteins or fats and are the most common source of energy. Proteins and fat are vital building components for body tissue and cells and are also a source of energy for the body.

Carbohydrates are not essential nutrients: the body can obtain all its energy from protein and fats. The brain cannot burn fat and needs glucose for energy, but the body can make this glucose from protein. Carbohydrates contain 3.75 and proteins 4 kilocalories per gram, respectively, while fats contain 9 kilocalories and alcohol contains 7 kilocalories per gram.

Foods that are high in carbohydrates include breads, pastas, beans, potatoes, bran, rice and cereals.

Based on evidence for risk of heart disease and obesity, the Institute of Medicine recommends that American and Canadian adults get between 40-65% of dietary energy from carbohydrates. The Food and Agriculture Organization and World Health Organization jointly recommend that national dietary guidelines set a goal of 55-75% of total energy from carbohydrates, but only 10% should be from Free sugars (their definition of simple carbohydrates).

 Classification

Dietitians and nutritionists commonly classify carbohydrates as simple (monosaccharides and disaccharides) or complex (oligosaccharides and polysaccharides). The term complex carbohydrate was first used in the Senate Select Committee publication Dietary Goals for the United States (1977), where it denoted “fruit, vegetables and whole-grains”. Dietary guidelines generally recommend that complex carbohydrates and nutrient-rich simple carbohydrates such as fruit and dairy products make up the bulk of carbohydrate consumption. The USDA’s Dietary Guidelines for Americans 2005 dispenses with the simple/complex distinction, instead recommending fiber-rich foods and whole grains.

The glycemic index and glycemic load systems are popular alternative classification methods which rank carbohydrate-rich foods based on their effect on blood glucose levels. The insulin index is a similar, more recent classification method which ranks foods based on their effects on blood insulin levels. This system assumes that high glycemic index foods and low glycemic index foods can be mixed to make the intake of high glycemic foods more acceptable.

Vitamins, which are not considered minerals, are organic compounds, some of which contain heavy elements such as iodine and cobalt. The dietary focus on “minerals” derives from an interest in supporting the biosynthetic apparatus with the required elemental components. Appropriate intake levels of certain chemical elements is thus required to maintain optimal health. Commonly, the requirements are met with a conventional diet. Excessive intake of any element (again, usually as an ion) will lead to poisoning. For example, large doses of selenium are lethal. On the other hand, large doses of zinc are less dangerous but can lead to a harmful copper deficiency (unless compensated for, as in the Age-Related Eye Disease Study).

Dietary minerals classified as “macromineral” are required in relatively large amounts. Conversely “microminerals” or “trace minerals” are required relatively in minute amounts. There is no universally accepted definition of the difference between “large” and “small” amounts.

Essential minerals

At least seven minerals are required to support biochemical processes, many playing a role as electrolytes or in cell structure and function. In human nutrition, the dietary bulk “mineral elements” (RDA > 200 mg/day) are in alphabetical order (parenthetical comments on folk medicine perspective):

    * Calcium (for muscle, heart and digestive system health, builds bone, neutralizes acidity, supports synthesis and function of blood cells)

    * Chloride (for production of hydrochloric acid in the stomach and in cellular pump functions)

    * Magnesium is required for processing ATP and related reactions (health builds bone, increases alkalinity)

    * Phosphorus is a component of bones (see apatite) and energy processing and many other functions (bone mineralization)

    * Potassium is a systemic electrolyte and is essential in coregulating ATP with sodium

    * Sodium is a systemic electrolyte and is essential in coregulating ATP with potassium

 Trace minerals

Numerous minerals are required in trace amounts and are usually cofactors for enzymes. Some trace mineral elements (RDA < 200 mg/day) are (alphabetical order):

    * Cobalt is required for biosynthesis of vitamin B12 family of coenzymes

    * Copper is required component of many redox enzymes, including cytochrome c oxidase

    * Fluorine participates in formation of tooth enamel which contains fluoroapatite (see Water fluoridation)

    * Iodine is required for the biosynthesis of thyroxine

    * Iron is required for many proteins and enzymes, notably hemoglobin

    * Manganese is a cofactor in function of antioxidant enzymes such as superoxide dismutase

    * Molybdenum is required for xanthine oxidase and related oxidases

    * Nickel is present in urease

    * Selenium is required for peroxidase (antioxidant proteins)

    * Sulfur is an essential component of cysteine and methionine amino acids and participates as an enzyme cofactor

    * Zinc is pervasive and required for several enzymes such as carboxypeptidase, liver alcohol dehydrogenase, carbonic anhydrase

 Other trace minerals

Many elements have been suggested as required in human nutrition, but such claims have usually not been scientifically proven. One problem with identifying efficacy is because many elements are innocuous at low concentrations, so proof of efficacy is lacking. Definitive evidence for efficacy comes from characterization of a biomolecule with an identifiable and testable function. Of the many trace elements still lacking solid proof, chromium is often cited. Chromium(III) is implicated in sugar metabolism in humans, leading to a market for chromium picolinate.

    * Vanadium (There is no established RDA for vanadium. No specific biochemical function has been identified for it in humans, although vanadium is found in other organisms)

 Food sources

    * Dairy products, calcium-fortified foods, canned fish with bones (salmon, sardines), and green leafy vegetables for calcium

    * Nuts, soy beans, and cocoa for magnesium

    * Table salt (sodium chloride, the main source), sea vegetables, olives, milk, and spinach for sodium

    * Legumes, potato skin, tomatoes, and bananas for potassium

    * Table salt is the main dietary source for chlorine

    * Meat, eggs, and legumes for sulfur

    * Red meat, leafy green vegetables, fish (tuna, salmon), eggs, dried fruits, beans, whole grains, and enriched grains for iron.

Proteins, like carbohydrates, contain 4 kilocalories per gram as opposed to lipids which contain 9 kilocalories and alcohols which contain 7 kilocalories. The liver and to a much lesser extent the kidneys, can convert amino acids used by cells in protein biosynthesis into glucose by a process known as gluconeogenesis. The amino acids leucine and lysine are exceptions.

Sources of proteins

Dietary sources of protein include meats, eggs, grains, legumes, and dairy products such as milk and cheese. Of the over 20 amino acids used by humans, 12 nonessential amino acids can be synthesized by the body, and are not required in the diet (though there are exceptions for some in special cases). The 9 essential amino acids, however, cannot be created by the body and must come from dietary sources.

Most animal sources and certain vegetable sources have the complete complement of all 9 essential amino acids. However, it is not necessary to consume a single food source that contains all the essential amino acids, as long as all the essential amino acids are eventually present in the diet: see complete protein and protein combining.

 Protein quality

Different proteins have different levels of biological availability to the human body. Many methods have been introduced to measure protein utilization and retention rates in humans. They include biological value, Net Protein Utilization or NPU, and PDCAAS (Protein Digestibility Corrected Amino Acids Score) which was developed by the FDA as an improvement over the Protein Efficiency Ratio (PER) method. These methods examine which proteins are most efficiently used by the body. In general they conclude that animal complete proteins that contain all the essential amino acids such as milk, eggs, and meat, and the complete vegetable protein soy are of most value to the body.

Egg whites have been determined to have the standard biological value of 100 (though some sources may have biological values higher), which means that most of the absorbed nitrogen from egg white protein can be retained and used by the body. Since the amino acids found in plants are biologically different from those found in humans and animals, the biological value of plant protein sources is considerably lower. For example, corn has a BA of 70 while peanuts have a relatively low BA of 40.

 Digestion of protein

Digestion typically begins in the stomach when pepsinogen is converted to pepsin by the action of hydrochloric acid, and continued by trypsin and chymotrypsin in the intestine. The amino acids and their derivatives into which dietary protein is degraded are then absorbed by the gastrointestinal tract. The absorption rates of individual amino acids are highly dependent on the protein source; for example, the digestibility of many amino acids in humans differs between soy and milk proteins and between individual milk proteins, beta-lactoglobulin and casein. For milk proteins, about 50% of the ingested protein is absorbed between the stomach and the jejunum and 90% is absorbed by the time the digested food reaches the ileum. Biological value (BV) is a measure of the proportion of absorbed protein from a food which becomes incorporated into the proteins of the organism’s body.

 Dietary requirements

According to the recently updated Dietary Reference Intake guidelines, women aged 19–70 need to consume 46 grams of protein per day, while men aged 19–70 need to consume 56 grams of protein per day to avoid a deficiency. The difference is because men’s bodies generally have more muscle mass than those of women, or this may be attributed to weight difference by taking 0.8 g(of protein)/kg of body weight.

Because the body is continually breaking down protein from tissues, even adults who do not fall into the above categories need to include adequate protein in their diet every day. If enough energy is not taken in through diet, as in the process of starvation, the body will use protein from the muscle mass to meet its energy needs, leading to muscle wasting over time. If the body does not consume adequate protein in nutrition, then muscle will also waste as more vital cellular processes (e.g. respiration enzymes, blood cells) recycle muscle protein for their own requirements.

Other recommendations suggest 0.8 gram of protein per kilogram of bodyweight per day while other sources suggest that higher intakes of 1-1.4 grams of protein per kilogram of bodyweight for enhanced athletes or those with a large muscle mass.

How much protein needed in a person’s daily diet is determined in large part by overall energy intake, as well as by the body’s need for nitrogen and essential amino acids. Physical activity and exertion as well as enhanced muscular mass increase the need for protein. Requirements are also greater during childhood for growth and development, during pregnancy or when breast-feeding in order to nourish a baby, or when the body needs to recover from malnutrition or trauma or after an operation.

 Protein deficiency

 Protein deficiency in developing countries

Protein deficiency is a serious cause of ill health and death in developing countries. Protein deficiency plays a part in the disease kwashiorkor. War, famine, overpopulation and other factors can increase rates of malnutrition and protein deficiency. Protein deficiency can lead to reduced intelligence or mental retardation; see deficiency in proteins, fats, carbohydrates.

In countries that suffer from widespread protein deficiency, food is generally full of plant fibers, which makes adequate energy and protein consumption very difficult. Symptoms of kwashiorkor include apathy, diarrhea, inactivity, failure to grow, flaky skin, fatty liver, and edema of the belly and legs. This edema is explained by the normal functioning of proteins in fluid balance and lipoprotein transport.

Dr. Latham, director of the Program in International Nutrition at Cornell University claims that malnutrition is a frequent cause of death and disease in third world countries. Protein-energy malnutrition (PEM) affects 500 million people and kills 10 million annually. In severe cases white blood cell numbers decline and the ability of leukocytes to fight infection decreases.

 Protein deficiency in developed countries

Protein deficiency is rare in developed countries but small numbers of people have difficulty getting sufficient protein due to poverty. Protein deficiency can also occur in developed countries in people who are dieting or crash dieting to lose weight, or in older adults, who may have a poor diet. Convalescent people recovering from surgery, trauma, or illness may become protein deficient if they do not increase their intake to support their increased needs. A deficiency can also occur if the protein a person eats is incomplete and fails to supply all the essential amino acids.

 Excess protein consumption

Because the body is unable to store in the form of protein, excess consumed protein is broken down and converted into sugars or fatty acids. The liver removes nitrogen from the amino acids, so that they can be burned as fuel, and the nitrogen is incorporated into urea, the substance that is excreted by the kidneys. These organs can normally cope with any extra workload but if kidney disease occurs, a decrease in protein will often be prescribed.

Many researchers think excessive intake of protein forces increased calcium excretion. If there is to be excessive intake of protein, it is thought that a regular intake of calcium would be able to stabilize, or even increase the uptake of calcium by the small intestine, which would be more beneficial in older women.

Proteins are often progenitors in allergies and allergic reactions to certain foods. This is because the structure of each form of protein is slightly different; some may trigger a response from the immune system while others remain perfectly safe. Many people are allergic to casein, the protein in milk; gluten, the protein in wheat and other grains; the particular proteins found in peanuts; or those in shellfish or other seafood.

 Testing for protein in foods

The classic assay for protein concentration in food is the Kjeldahl method. This test determines the total nitrogen in a sample. The only major component of most food which contains nitrogen is protein (fat, carbohydrate and dietary fiber do not contain nitrogen). If the amount of nitrogen is multiplied by a factor depending on the kinds of protein expected in the food the total protein can be determined. On food labels the protein is given by the nitrogen multiplied by 6.25, because the average nitrogen content of proteins is about 16%. The Kjeldahl test is used because it is the method the AOAC International has adopted and is therefore used by many food standards agencies around the world.

An essential amino acid or indispensable amino acid is an amino acid that cannot be synthesized de novo by the organism (usually referring to humans), and therefore must be supplied in the diet.

Essentiality vs. conditional essentiality in humans

Nine amino acids are generally regarded as essential for humans: phenylalanine, valine, threonine, tryptophan, isoleucine, methionine, histidine, leucine, and lysine. Arginine is required by infants and growing kids. They are called essential not because they are more important to life than the others, but because the body does not synthesize them, making it essential to include them in one’s diet in order to obtain them. In addition, the amino acids arginine, cysteine, glycine, glutamine and tyrosine are considered conditionally essential, meaning they are not normally required in the diet, but must be supplied exogenously to specific populations that do not synthesize it in adequate amounts. An example would be with the disease phenylketonuria (PKU). Individuals living with PKU must keep their intake of phenylalanine extremely low to prevent mental retardation and other metabolic complications. However, phenylalanine is the precursor for tyrosine synthesis. Without phenylalanine, tyrosine cannot be made and so tyrosine becomes essential in the diet of PKU patients.

Which amino acids are essential varies from species to species, as different metabolisms are able to synthesize different substances. For instance, taurine (which is not, by strict definition, an amino acid) is essential for cats, but not for dogs. Thus, dog food is not nutritionally sufficient for cats, and taurine is added to commercial cat food when the base ingredients do not meet the requirements of the cat, but not to dog food.

The distinction between essential and non-essential amino acids is somewhat unclear, as some amino acids can be produced from others. The sulfur-containing amino acids, methionine and homocysteine, can be converted into each other but neither can be synthesized de novo in humans. Likewise, cysteine can be made from homocysteine but cannot be synthesized on its own. So, for convenience, sulfur-containing amino acids are sometimes considered a single pool of nutritionally-equivalent amino acids. Likewise arginine, ornithine, and citrulline, which are interconvertible by the urea cycle, are considered a single group.

 Recommended daily amounts

The following table lists the recommended daily amounts for essential amino acids in humans, together with their standard one-letter abbreviations. In some cases, humans can use either of two amino acids, so only the total matters.

Taurine may be necessary to preserve arterial and collagen pliability at 2 mg/kg/day, small but needed (142 mg/day per 70 kg human).

 Use of essential amino acids

Foodstuffs that lack essential amino acids are poor sources of protein equivalents, as the body tends to deaminate the amino acids obtained, converting proteins into fats and carbohydrates. Therefore, a balance of essential amino acids is necessary for a high degree of net protein utilization, which is the mass ratio of amino acids converted to proteins to amino acids supplied.

All essential amino acids may be obtained from plant sources, and even strict vegetarian diets can provide all dietary requirements, provided they are based on a variety of whole plant foods. Some believe that careful monitoring of nutrient levels is important in strict vegetarian diets, but there are virtually no cases of protein-deficiency among populations consuming adequate calories. The only common cases of protein-deficiency occur among populations that are chronically undernourished.

Complete proteins contain a balanced set of essential amino acids for humans. Animal sources such as meat, poultry, eggs, fish, milk, and cheese provide all of the essential amino acids. Complete proteins are also found in some plant sources such as spirulina, quinoa, soy, buckwheat, hempseed, and amaranth, among others.

The net protein utilization is profoundly affected by the limiting amino acid content (the essential amino acid found in the smallest quantity in the foodstuff), and somewhat affected by salvage of essential amino acids in the body. It is therefore a good idea to mix foodstuffs that have different weaknesses in their essential amino acid distributions. This limits the loss of nitrogen through deamination and increases overall net protein utilization.

 Mnemonics

Using the one letter designation shown above, mnemonic devices have been developed for students wanting or needing to memorize the essential amino acids. Previous devices have utilized the first letter of the amino acids name, and in general did not include arginine which is not always essential. One mnemonic device that has been used in the past is PVT TIM HALL.

Another method uses the first letter of each essential amino acid to begin each word in a phrase, such as: “Any Help in Learning These Little Molecules Proves Truly Valuable.” This method begins with the two amino acids that need some qualifications as to their requirements.

Note that these devices work by using the first letter of the actual amino acids name. Due to repetition of letters, several amino acids have one letter abbreviations that are different than their first letter (e.g. lysine is K). Thus the complete list of essential amino acids utilizing one-letter codes is MILKVWTHFR.

A mnemonic that involves only the true one-letter codes for each amino acid is: “I Have Received Much Kudos for Learning These Very Well,” for IHRMKFLTVW.

In the United States, advertising for dietary supplements is required to include a disclaimer that the product is not intended to treat, diagnose, mitigate, prevent, or cure disease, and that any health claims have not been evaluated by the Food and Drug Administration. In some cases, dietary supplements may have unwanted effects, especially if taken before surgery, with other dietary supplements or medicines, or if the person taking them has certain health conditions. Vitamin supplements may also contain levels of vitamins many times higher, and in different forms, than one may ingest through food.

Intake of excessive quantities can cause vitamin poisoning, often due to overdose of Vitamin A and Vitamin D (The most common poisoning with multinutrient supplement pills does not involve a vitamin, but is rather due to the mineral iron). Due to toxicity, most common vitamins have recommended upper daily intake amounts.

Since 2005, suppliers have distinguished their products as either Medical Grade or Pharmaceutical Grade products. Both of these classifications indicate products that are manufactured to be easily absorbed by the body. Normal vitamin manufacturing is not regulated in the United States to the same standards as are medicinal pharmaceuticals, although U.S. vitamins which are manufactured for food consumption by humans or animals must be manufactured to Food Chemicals Codex (FCC), grade, commonly called “food grade”.

 Governmental regulation of vitamin supplements

Most countries place dietary supplements in a special category under the general umbrella of foods, not drugs. This necessitates that the manufacturer, and not the government, be responsible for ensuring that its dietary supplement products are safe before they are marketed. Unlike drug products, that must explicitly be proven safe and effective for their intended use before marketing, there are often no provisions to “approve” dietary supplements for safety or effectiveness before they reach the consumer. Also unlike drug products, manufacturers and distributors of dietary supplements are not generally required to report any claims of injuries or illnesses that may be related to the use of their products.

 Names in current and previous nomenclatures

The reason the set of vitamins seems to skip directly from E to K is that the vitamins corresponding to “letters” F-J were either reclassified over time, discarded as false leads, or renamed because of their relationship to “vitamin B”, which became a “complex” of vitamins. The German-speaking scientists who isolated and described vitamin K (in addition to naming it as such) did so because the vitamin is intimately involved in the Koagulation of blood following wounding. At the time, most (but not all) of the letters from F through J were already designated, so the use of the letter K was considered quite reasonable.

The following table lists chemicals that had previously been classified as vitamins, as well as the earlier names of vitamins that later became part of the B-complex:

Previous name Chemical name             Reason for name change

Vitamin B4                       Adenine                                       DNA metabolite

Vitamin B8                 Adenylic acid                                     DNA metabolite

Vitamin F         Essential fatty acids             Needed in large quantities (does

not fit the definition of a vitamin).

Vitamin G                     Riboflavin                        Reclassified as Vitamin B2

Vitamin H                      Biotin                Reclassified as Vitamin B7

Vitamin J                Catechol, Flavin                                Protein metabolite

Vitamin L1           Anthranilic acid                       Protein metabolite

Vitamin L2          Adenylthiomethylpentose             RNA metabolite

Vitamin M                    Folic acid                          Reclassified as Vitamin B9

Vitamin O                        Carnitine                                     Protein metabolite

Vitamin P                       Flavonoids                  No longer classified as a vitamin

Vitamin PP                        Niacin                           Reclassified as Vitamin B3

Vitamin U                  S-Methylmethionine                              Protein metabolite

Let’s talk about exercise and why it is essential for good health and weight loss. Most people who exercise regularly will tell you that it is the key, the most important single thing they do to stay healthy and fit. Many of those people won’t be reading this newsletter or going to our diet site because they don’t have any weight they need to lose. This newsletter is really intended for those of us who do have weight to lose, be it ten pounds or a hundred pounds.

Exercise is an essential component of any weight loss plan. Without it, you will have to diet much more strenuously to achieve your goal. Now I’m not talking about running five miles and then hitting the gym for two hours of weight lifting every day. The kind of exercise needed in a successful weight loss plan is basic and easy. Walking for one half hour daily is a very good start. Kenneth Cooper showed the world through very well done scientific studies over several years, that walking is a safe and effective way to get the benefits of exercise. Swimming is also great. Riding the stationary bike works too. The key is to start slowly and slowly progress. Many people make the mistake of overdoing their new exercise program in the beginning and after two days they are so tired and sore, they just quit. That won’t do you any good at all. That is not the way to do it.

Begin any new exercise program slowly. Let’s use walking as an example of how to do it right. Figure out a time that you can walk each day. Begin with just thirty minutes of moderate speed (normal) walking. After two weeks, increase the time by fifteen minutes. Now do this forty five minute walk for one month and then increase by another fifteen minutes. Now you are walking for one hour daily. Do this one hour walk for another month before any increase in duration or intensity. Now you may be ready to start jogging instead of just walking. Maybe you don’t really want to jog. No problem, you don’t have to. You can stay with your walk forever if you like; just pick up the speed a little. The formula described above works exactly the same for swimming or riding a bike.

Now let’s talk about why exercise is important to losing weight and keeping it off permanently. Daily aerobic exercise (walking, swimming, biking) raises your basic metabolic rate (BMR). It resets your metabolic thermostat to a higher setting. Your BMR goes up during exercise and stays at a higher level than normal throughout the day. You burn more calories and you lose weight. Simple really, but many people fail to include this essential ingredient in their weight loss plan. Exercise also increases blood flow in you brain, and makes your heart and lungs stronger and more efficient. You will think better, feel better, and even sleep better. All good things.

Let’s finish by talking a little about lifting weights. Weight lifting is basically an anaerobic form of exercise; not at all like the aerobic types that we talked about before. When you lift weights you stress an individual muscle or muscle group and strengthen it through a process of muscle breakdown and repair. Building lean muscle is a good idea, and it will help you stay trim, but it should only be added to your weight loss plan after you have lost approximately twenty percent of the weight you want to lose. At that point, it is a very good thing to do. Again, start slowly. You can, and should, eventually combine aerobic exercise with some weight lifting in you routine to achieve optimal health. I personally do aerobic exercise every day and lift twice a week.

That is all for this month. Please visit out website at arizonadietproducts.com. You will find all the products you need for losing weight and also many informative articles on health. My next newsletter in August will focus on diabetes and weight loss. As always, “the key to good dieting is good nutrition.”

Dr. Brad Manny

Owner/Director Arizona Diet Products

History

Niacin was first described by Weidel in 1873 in his studies of nicotine. The original preparation remains useful: the oxidation of nicotine using nitric acid. Niacin was extracted from livers by Conrad Elvehjem who later identified the active ingredient, then referred to as the “pellagra-preventing factor” and the “anti-blacktongue factor.” When the biological significance of nicotinic acid was realized, it was thought appropriate to choose a name to dissociate it from nicotine, in order to avoid the perception that vitamins or niacin-rich food contains nicotine. The resulting name ‘niacin’ was derived from nicotinic acid + vitamin.

Niacin is referred to as Vitamin B3 because it was the third of the B vitamins to be discovered. It has historically been referred to as “vitamin PP.”

 Dietary needs

Severe deficiency of niacin in the diet causes the disease pellagra, whereas mild deficiency slows the metabolism, causing decreased tolerance to cold. Dietary niacin deficiency tends to occur only in areas where people eat corn (maize), the only grain low in niacin, as a staple food, and that do not use lime during meal/flour production. Alkali lime releases the tryptophan from the corn in a process called nixtamalization so that it can be absorbed in the intestine, and converted to niacin.

The recommended daily allowance of niacin is 2-12 mg/day for children, 14 mg/day for women, 16 mg/day for men and 18 mg/day for pregnant or breast-feeding women.

Note: Niacin synthesis is deficient in carcinoid syndrome because of metabolic diversion of its precursor, tryptophan, to form serotonin.

 Pharmacological uses

Niacin, when taken in large doses, blocks the breakdown of fats in adipose tissue, thus altering blood lipid levels. Niacin is used in the treatment of hyperlipidemia because it reduces very-low-density lipoprotein (VLDL), a precursor of low-density lipoprotein (LDL) or “bad” cholesterol. Because niacin blocks breakdown of fats, it causes a decrease in free fatty acids in the blood and, as a consequence, decreased secretion of VLDL and cholesterol by the liver.

By lowering VLDL levels, niacin also increases the level of high-density lipoprotein (HDL) or “good” cholesterol in blood, and therefore it is sometimes prescribed for patients with low HDL, who are also at high risk of a heart attack.

Niacin is sometimes consumed in large quantities by people who wish to fool drug screening tests, particularly for lipid soluble drugs such as marijuana. It is believed to “promote metabolism” of the drug and cause it to be “flushed out.” Scientific studies have shown it does not affect drug screenings, but can pose a risk of overdose, causing arrhythmias, metabolic acidosis, hyperglycemia, and other serious problems.

 Toxicity

People taking pharmacological doses of niacin (1.5 - 6 g per day) often experience a syndrome of side-effects that can include one or more of the following:

    * Dermatological complaints

          o facial flushing and itching

          o dry skin

          o skin rashes including acanthosis nigricans

    * Gastrointestinal complaints

          o dyspepsia (indigestion)

    * Liver toxicity

          o fulminant hepatic failure

    * Hyperglycemia

    * Cardiac arrhythmias

    * Birth defects

Facial flushing is the most commonly-reported side-effect. It lasts for about 15 to 30 minutes, and is sometimes accompanied by a prickly or itching sensation, particularly in areas covered by clothing. This effect is mediated by prostaglandin and can be blocked by taking 300 mg of aspirin half an hour before taking niacin, or by taking one tablet of ibuprofen per day. Taking the niacin with meals also helps reduce this side-effect. After 1 to 2 weeks of a stable dose, most patients no longer flush. Slow- or “sustained”-release forms of niacin have been developed to lessen these side-effects. One study showed the incidence of flushing was significantly lower with a sustained release formulation though doses above 2 g per day have been associated with liver damage, particularly with slow-release formulations.

High-dose niacin may also elevate blood sugar, thereby worsening diabetes mellitus. Hyperuricemia is another side-effect of taking high-dose niacin, and may exacerbate gout. Niacin at doses used in lowering cholesterol has been associated with birth defects in laboratory animals, with possible consequences for infant development in pregnant women.

Niacin at extremely high doses can have life-threatening acute toxic reactions. Extremely high doses of niacin can also cause niacin maculopathy, a thickening of the macula and retina which leads to blurred vision and blindness.

 Inositol hexanicotinate

One popular form of dietary supplement is inositol hexanicotinate, usually sold as “flush-free” or “no-flush” niacin (although those terms are also used for regular sustained-release.) While this form of niacin does not cause the flushing associated with the nicotinic acid form, it is not clear whether it is pharmacologically equivalent in its positive effect.

Different species have very different essential nutrients. Most essential nutrients are substances that are metabolically necessary but cannot be synthesized by the organism. Dietary minerals, for example, cannot be synthesized in biological systems, so (for example) a human must obtain the iron they need to build hemoglobin from their diet. Of course, this iron is recycled, but some is inevitably lost, for example during menstruation.

Many essential nutrients are toxic in large doses (see hypervitaminosis or the nutrient pages themselves below). Some can be taken in amounts larger than required in a typical diet, with no apparent ill effects. Linus Pauling said of vitamin B3, (either niacin or niacinamide), “What astonished me was the very low toxicity of a substance that has such very great physiological power. A little pinch, 5 mg, every day, is enough to keep a person from dying of pellagra, but it is so lacking in toxicity that ten thousand times as much can [sometimes] be taken without harm.” A similar statement can be made about vitamin C and some other vitamins.

List of essential nutrients

    * Essential substances often not considered to be nutrients:

          o Oxygen

          o Water

          o Sunlight

    * Essential fatty acids:

          o Linolenic acid (the shortest chain omega-3 fatty acid)

          o Linoleic acid (the shortest chain omega-6 fatty acid)

    * Essential amino acids necessary for all humans:

          o Histidine