Introduction to Nutrition Chapter 7
Nutrigenetics
the study of how inherited genetic variations influence the body's response to specific nutrients and nutrient combinations
Nutrigenomics
the study of how nutrients affect the expression of a person's genome
Heart disease and cancer are the leading causes of death in developed countries including the US. In these nations....
the typical Western diet that contains high amounts of red meat adn processed meats has been associated with increased risk of certain chronic disease, particularly heart disease, colorectal cancer, and diabetes.
Proteins also help maintain acid-base balance, the proper pH of body fluids. To function properly, blood and tissue fluids need to maintain a pH of....
7.35 to 7.45, slightly basic.
A food allergy is an inflammatory response that results when the...
body's immune system reacts inappropriately to one or more harmless substances(allergens) in a food.
Buffer
can product the pH of a solution. Proteins can act as buffers because they have acidic and basic components.
As a result of deamination, the amino acid that gives up its amino group becomes a...
carbon skeleton
Monitoring blood phenylalanine is especially important during pregnancy. An expectant woman who has PKU must...
carefully control her phenylalanine level to avoid exposing her embryo/fetus to excessive amounts of amino acid.
Structural proteins such as collagen are in...
cartilage, ligament, and bone tissues.
Protein digestion begins the stomach. HCL acid...
denatures food and proteins and activates pepsin from the inactive form of the enzyme, pepsinogen.
Nutritional genomics may explain why interventions can have...
different effects on the health of different individuals.
A pescavegetarian eats...
fish, eggs, and dairy products but avoids red meat, poultry, or other animal products
Epinephrine is made from the amino acid tyrosine and serotonin is...
made from the amino acid tryptophan. Thus, tryptophan and tyrosine are precursors for these amines.
Amino acids that are not incorporated into proteins become...
part of a small amino acid pool, a readily available supply of amino acids that cells can use for future protein synthesis.
Because gluten may be used to make medications, dietary supplements, and lipsticks...
people with celiac disease should rad the ingredient list to determine whether gluten is present.
On the other hand, allergies to peanuts, tree nuts, fish, and shellfish tend to...
persist into adulthood.
Accurate diagnosis of a food allergy should be undertaken by an immunologist, a...
physician who specializes in the diagnosis and treatment of allergies.
Protein needs increase during...
pregnancy, breastfeeding, periods of rapid growth, and recovery from serious illnesses, blood losses, and burns.
Kwashiorkor
primarily occurs in developing countries where mothers commonly breastfeed their infants until they give birth to another child.
Green peas, for example, are good sources of lysine, but they contain...
they tend to be low in lysine.
PKU is an example of an inborn error of amino acid metabolism that is..
treated with a special diet.
Most plant foods are poor sources of one or more essential amino acids, particularly....
tryptophan, threonine, lysine, and methionine.
Healthy children and adults will have minimal, if any....
undigested protein entering the large intestine and being excreted in feces.
The signs and symptoms of celiac disease vary from person to person but...
usually include abdominal bloating, chronic diarrhea, and weight loss.
Vegans have lower calcium intakes and a higher risk of bone fractures than...
vegetarians who include milk and milk products in their diets.
Currently available methods and equipment can detect this amount of gluten; equipment to...
verify lower levels is not available at this time.
The effectiveness of a specific diet, dietary supplement, medications, or lifestyle intervention may...
be largely dependent on one's genes. Such differences may need to be considered when prescribing treatments.
People often associate protein with animal foods, but...
beans, nuts, seeds, grains, and certain vegetables are good sources of protein.
Children with kwashiorkor have some subcutaneous....
(under the skin) fat, and their swollen cheeks, arms, legs, and bellies make them look well fed, but their appearance is misleading.
Furthermore, vegans tend to be leaner than nonvegans. It is difficult though to pin point diet as....
being responsible for vegetarians' good health status.
To help restore the pH level to within the normal range, the basic portions of molecules....
bind to the excess H+, neutralizing the excess ions and raising the pH (becoming less acidic).
A young woman who consumes 15% of her calories from protein on a 2000-kcal diet is...
eating approximately 75 grams of protein per day, which is about the amount of protein in 10-ounce steak.
An ovovegetarian
eats eggs, and a lactoovovegtarian consumes milk products and eggs.
Transamination
occurs when the nitrogen-containing group is transferred to another substance to make a nonessential amino acid.
If a diet contains adequate amounts of protein, then eating more is not better. In many parts of the world, the lack...
of foods containing high-quality proteins is a serious problem, particularly for young children.
A food intolerance is not the same as food allergy because the...
offending substance in the food does not trigger the body's immune response.
A dipeptide forms when two amino acids bond, and a molecule of water is...
released in the process.
Many common menu items can be converted into vegetarian foods by...
removing the meat, fish, or poultry.
Amounts of limiting amino acids in a food determine whether...
the item has a high or low Biological value.
Undernutrition
the lack of food, is often widespread in poor nations in which populations endure frequent famine resulting from crop failures, political unrest, or civil wars.
Advantages of vegetarian diets
High Vitamin C, E, and folic acid, Phytochemicals, Fiber, Magnesium and potassium. Low in saturated fatty acids.
Low UUN (<12 g) May Indicate:
Inadequate protein intake, malnutrition, kidney problem
Intuitively, the idea of eating more protein to improve one's health seems logical, but...
protein is no different from other nutrients.
In some proteins, two or more polypeptide chains associate with each other to form large complexes. This is....
quaternary structure
The digestibility and amino acid composition of a protein are the two key factors in determining the quality of the protein:
Biological value (BV) and Protein digestibility corrected amino acid score (PDCAAS)
Low BUN (<6mg/dL) May Indicate:
Liver failure, Inadequate protein intake, Malnutrition, Overhydration (too much water in the blood stream).
In addition to signaling excessive protein intake, an elevated....
Urine urea nitrogen may indicate excessive breakdown of protein in the body.
Possible Disadvantages to Vegetarian diets:
Vitamins B-12, D, and riboflavin, Zinc, iron, and calcium, Omega-3 fatty acids, Certain essential amino acids, energy
Vegetarian diets are often lower in fat and energy than....
Western diets that contain animal foods, particularly plenty of red meat.
A peanut butter sandwich also combines two foods that supply complementary plant proteins. Peanuts are...
a fair source of lysine, while bread provides some methionine but it is very low in lysine.
Immune system cells in the small intestine recognize the food protein as....
a foreign substance and try to protect the body by mounting a defensive response.
When food is limited, it is often more difficult for children than for adults to obtain nutritionally adequate diets. Adults may be...
able to consume enough plant proteins to meet their protein and energy needs, but children have smaller stomachs and higher energy and protein needs per pound of body weight than adults.
Amines
are compounds that include amino groups in their chemical structures.
Vegetarians
are individuals who rely heavily on plant foods; they may or may not include some animal foods in their diets.
Complementary combinations
are mixtures of certain plant foods that provide all essential amino acids without adding animal proteins. To make dishes that contain complementary amino acids combinations, consumers must know (1) which plant foods are good protein sources and (2) which essential amino acids are limiting or low in those plant foods.
Additionally, they should educate teachers and other adults who...
associate with the allergic child about the importance of not exposing the youngster to specific foods.
Proteins in blood such as albumin, also help maintain the proper distribution of fluids in blood and body tissues. The force of...
blood pressure moves watery fluid out of the blood stream and into tissues.
Children have higher protein and energy needs per pound of...
body weight than an adult. Because plant foods add bulk to the diet, vegan children are likely to eat far less food than adult vegans because they become full sooner during meals.
However, adding sunflower seeds, kidney or black beans, cashews and bread cubes to the salad...
boosts the amount of protein and provides a complete mix of amino acids.
Most plant foods are not sources of high-quality proteins. Quinoa and soy protein are exceptions. Quinoa is...
botanically related to sugar beets and spinach, but the quality and amount of protein in quinoa seeds are superior to those of many cereal grains.
Enzymes released by the absorptive cells of the small intestine...
break down most of the shortened peptides into dipeptides, tripeptides, and individual amino acids.
Trypsin and chymotrypsin
break down polypeptides into shorter peptides and amino acids.
For decades, medical experts have treated infants who have...
certain inborn errors of metabolism with special diets. An inborn error of metabolism occurs when a gene undergoes a mutation, that is a change in the typical sequence of the gene's DNA components.
When a recipe calls for "flour" it is often best to use a...
combination of gluten-free flours, including rice flour, potato starch flour, or soy flour.
Certain parts of plants contain more protein than other parts. Seeds, tree nuts, and legumes supply...
more protein per serving than servings of frit or the edible leaves, roots, flowers, and stems of vegetables.
Eating a gluten-free diet means avoiding all foods, beverages, medications, and supplements that contain gluten. For many, the...
most challenging aspect of gluten-free eating is avoiding products made from wheat, one of the most commonly consumed grains in the US.
The body does not store excess amino acids in...
muscles or other tissues. The unnecessary amino acids undergo deamination, and some of the excess NH2 is transported to the liver in glutamate (a form of glutamic acid).
Consumption of red meats and processed meats, such as ham and sausage, has also...
been associated with increased risk of pancreatic cancer as well as stomach and esophageal cancer.
Since 1997, the prevalence of food allergies among children under 18 years of age has...
been increasing in the US. As they mature, children often "outgrow" allergies to what, milk, soy, and eggs.
A 2013 dietary intervention study found that a gluten-free/casin-free (GF/CF) diet was....
beneficial for autistic children. However, other studies have shown no benefits for autisitc children who follow GF/CF, casein-free, or gluten-free diets.
The kidneys filter urea, small amounts of ammonia, and creatinine (a nitrogen-containing waste produced by muscles) from..
blood and eliminate the compounds in urine.
Processed soybeans are used to make a variety of...
nutritious foods, including soy milk, infant formula, and meat substitutes.
Compared to people who eat meat, vegetarians tend to have a lower risk of...
obesity, type 2 diabetes, hypertension, and certain cancers.
In many cases, the child suffering from kwashiorkor does not...
obtain enough energy and eventually develops marasmic kwashiorkor, a condition characterized by edema and wasting.
Vegetarians who do not consume seafood may need to...
obtain omega-3 fatty acids by eating algae or taking algae supplements.
The amino acid pool is endogenous, or internal source of nitrogen. The human body...
obtains about two thirds of its amino acid supply from endogenous sources and the remainder from exogenous (dietary) sources.
A lactovegetarian
obtains animal protein by consuming milk and milk products, including yogurt, cheese, and ice cream.
Secondary structure
reflects the polypeptide chain's coiling because of chemical attractions between certain components of the chain's amino acids.
Vegetarians often adopt other healthy lifestyle practices, such as exercising regularly; practicing...
relaxation activities, such as yoga or meditation; and avoiding tobacco products and excess alcohol.
The shift away from providing standard dietary advice and...
toward personalized dietary planning is an early phase. Students who study dietetics or human nutrition may consider taking courses in genetics, specifically nutritional genomics, to prepare for this emerging trend.
Heart disease and cancer are the leading causes of death in developed countries, including the US. In these nations, the...
typical Wester diet that contains high amounts of red meat and processed meats has been associated with increased risk of certain chronic diseases, particularly heart disease
Children affected by kwashiorkor have stunted growth....
unnaturally blond, sparse, and brittle hair; and patches of skin that have lost their normal coloration.
Urea levels in both blood and urine are...
used as markers of dietary protein intake and chronic disease.
A healthy adult's RDA for protein is...
0.8 g/kg of body weight.
The incidence of diagnosed autism has increased more than...
10-fold in the past 20 years. Today, ASD affect 1 in 68 children in the US.
Traditionally, amino acids are classified as either nonessential or essential according to the body's ability to make them. A healthy body can make...
11 of the 20 amino acids that are in proteins. These compounds are the nonessential amino acids.
Animal foods generally provide higher amounts of protein than similar quantities of plant foods. For example:
A 3-ounce serving of broiled lean ground beef supplies 23 grams of protein; a 3-ounce serving of steamed broccoli or cooked carrots provides only about 1 of protein.
Sickle cell anemia is a common genetic disorder that generally affects people with...
African, Caribbean, or Mediterranean ancestry. There is no cure
Keratin is another structural protein; it is in hair, nails, and skin....
Contractile proteins in muscles enable movement. Proteins in the retina of the eye enable sight, and other proteins in blood are necessary for blood to clot properly.
Food manufacturers must identify potentially allergenic ingredients on product labels. The top food allergens in the US are:
Cow's milk, eggs, fish, crustacean shellfish, tree nuts, peanuts, wheat, soybeans
Proteins are necessary for muscle development and maintenance, but the estimated 100,000 proteins in the body have a wide variety of functions:
Skin, blood, nerve, bone--all cells in the body---contain proteins.
With careful planning, vegetarians can overcome the nutritional limitations of a plant based diet and consume adequate nutrients...
The MyPlate website also offers suggestions for planning nutritionally adequate meatless meals.
In many parts of the world, the lack of foods containing high quality proteins is...
a serious problem, particularly for young children. Protein deficiency interferes with a child's normal growth and development, and contributes to may childhood deaths.
Pregnant vegan women should consult with their physicians about the need to take...
a vitamin B-12 supplement to reduce the likelihood of having a baby who is deficient in this nutrient.
Urine urea nitrogen (UUN) is...
also evaluated as part of certain pateints' health care screening. It can also be used as a marker of protein intake. The more protein a person consumes, the more amino acids needs to undergo deamination, and therefore, urea synthesis will increase.
At this time, there is no cure for ASD. Many caregivers turn to...
alternative therapies for the disorders, including special diets that exclude gluten and casein, a protein in milk.
People with liver or kidney diseases may need to avoid protein-rich diets and...
amino acid supplements because metabolizing the excess amino acids is a burden to their bodies.
A protein lacking one of the essential amino acids will have...
an amino acid composition score of 0.
Some people have no obvious signs or symptoms of the disease, despite the damage occurring to their small intestines. Serious health problems such as...
anemia, osteoporosis, liver disease, and intestinal cancer can result from untreated celiac disease.
Proteins
are complex organic molecules that are chemically similar to lipids and carbohydrates because they contain carbon, hydrogen, and oxygen atoms.
Several nonessential amino acids are conditionally essential, which means they become essential under certain conditions. For example:
cells make cysteine from methionine and serine. If a person's methionine and serine intake is inadequate, however his or her body cannot make enough cysteine to meet is needs. Dietary sources of the amino acid then become necessary
Although cells need amino acids to function properly, in some cases....
certain amino acids or proteins can harm the body and even cause death.
In the US, as many as 1 in 141 people has celiac disease. Although the tendency to develop the...
disease is probably inherited, environmental factors often play a role by triggering the condition. A serious viral infection or severe emotional stress, for example, may activate the disorder in a genetically susceptible person.
Normal values for BUN are between 6 and 20 mg/dL. An elevated BUN level occurs when the kidneys are...
diseased and unable to filter urea from the blood properly.
When an amino acid is not available, production of a protein stops. The partially made polypeptide chain is...
dismantled, and its amino acids are returned to the pool.
Thus, vegetarians may feel "full" soon after...
eating a meal of plant foods, and they may not consume as much energy and nutrients as they need.
The World Health Organization has...
guidelines for identifying and treating children with PEM. According to these guidelines, treatments for kwashiorkor, marasmic kwashiorkor, and marasmus are similar. The sickest72'; 3.children need hospitalization, carefully controlled refeeding, and frequent health assessments to recover form PEM.
Metabolic process can produce acidic or products. If a particular body fluid becomes too acidic or too basic, cells can...
have difficulty functioning and may die.
Many people experience food intolerances, unpleasant physical reactions including...
headaches and intestinal discomfort, after they consume nonprotein substances in foods such as lactose, monosodium glutamate (MSG), or sulfites.
Most animal sources of protein, including milk, cheese, and meat, have a...
high biological value most often between 90 to 100%
If the DNA code is faulty, however, the wrong amino acid will be....
inserted into the chain consistently, forming an abnormal polypeptide. Such errors often cause genetic defects that have devastating, even deadly effects.
Pepsin initiates enzymatic digestion of proteins....
into smaller polypeptides. Soon after the polypeptides enter the small intestine, the pancreas secretes proteins into smaller polypeptides.
Not every mixture of plant foods creates a complementary combination. For example...
making a fruit salad by combining apples, grapes, and oranges will not provide a complementary mixture of essential amino acids.
Protein deficiency interferes with a child's normal growth and development, and contributes to...
many childhood deaths.
The body of a starving person loses most of its subcutaneous fat and deeper fat stores. The...
marasmic person is so thin that his or her ribs, hips, and spinal column are visible through the skin.
Nevertheless, dietitians generally consider....
marasmus, kwashiokor, and marasmic kwashiorkor as forms of PEM.
Normal values for Urine urea nitrogen for...
measured from a 24-hour urine sample are between 12 and 20 g.
About 3.2% of American adults do not eat...
meat, fish, or poultry, and about 0.5% of adults avoid eating any food from animal sources.
Restaurants may offer vegetarian menu items, or their cooks can modify menu items by substituting....
meatless sauces, omitting meat from stir-fries, and adding vegetables or pasta in place of meat.
As a result, phenylamine or its toxic by-products build up in tissues and damage cells, including...
nerve cells in the brain. If PKU is not diagnosed and treated within a few weeks of birth, the affected infant can develop intellectual disability during the first year of life.
Refeeding results in positive nitrogen balance until....
nitrogen equilibrium is restored.
As of 2013, the FDA has adopted a gluten-free labeling standard. According to the FDA, a...
product can be labeled as gluten-free if it contains less than 20 parts per million of gluten, the equivalent of about 6 mcg of gluten per serving.
Skin testing is a reliable way to identify allergens. Although hair analysis, cytotoxic or electrodermal testing, and kinesiology are...
promoted by alternative medical practitioners to diagnose allergies, these are unproven diagnostic methods.
In most cases, the allergen is a protein. In many cases...
protein in a food does not undergo complete digestion, and the small intestine absorbs the whole molecule.
At this time, clinicians do not have a...
reliable method of diagnosing gluten sensitivity, sot hey rely on patient-reported symptoms to identify cases of the condition. Like celiac disease, treatment for gluten sensitivity involves a gluten-free diet.
To make the amino acid alanine, for example, liver cells...
remove the amino group (NH2) from the glutamic acid glutamate and transfer it to pyruvic acid. Transamination reactions are reversible.
The remaining nine amino acids are essential amino acids that must be...
supplied by foods, because the body cannot synthesize them or make enough to meet its needs. Sometimes, nonessential and essential amino acids are referred to as "dispensable" and indispensable amino acids, respectively.
These situations occur because protein synthesis in cells cannot proceed when the...
supply "pool" of amino acids is lacking in one or more of the essential amino acids.
High-quality proteins are also...
well digested and absorbed by the body.
In the past, children with PKU were often allowed to eat regular foods after they....
were about 6 years of age. The importance of continuing the low-phenylalanine diet became evident when many of the children experienced learning and behavioral problems as they matured.
People with the disease cannot tolerate foods that contain gluten, a protein in...
wheat, barley, and some other cereal grains.
To determine a person's RDA for protein, multiply his or her weight in kilograms by...
0.8 g. If the individual is underweight or overweight, use a healthy weight for the person's height when making this calculation.
Proteins are comprised of smaller chemical units called amino acids. The human bod contains proteins made from...
20 different amino acids. Each has a carbon atom that anchors a hydrogen atom and three different groups of atoms: the amino or nitrogen-containing group, the R group (side chain), and the carboxylic acid group.
A 3-ounce serving of almonds, dry-roasted peanuts, or sunflower seed kernels supplies about....
20 grams of protein. Many seeds and nuts however, pack a lot of calories from fat.
Fruits are nutritious foods, but they are generally poor sources of protein. Similarly, combining....
Boston, iceberg, and romaine varieties of lettuce with carrots and onions makes a tasty salad, but simply mixing leafy greens with other vegetables does not make a complementary combination.
High BUN (>20 mg/dL) May Indicate:
Congestive heart failure, Excessive protein intake (generally considered greater than 100 g/day), GI bleeding, Heart attach, Kidney disease, kidney failure, urinary tract obstruction, shock
Proteins, however, also contain nitrogen, an element cells need to make...
a wide array of important biological compounds such as enzymes and hormones. Plants, animals, bacteria, and even viruses contain proteins.
3 ounces of almonds, dry-roasted peanuts, or sunflower seed kernels, and you will...
add 500 kcal to your diet.
The food source with the highest biological value, 100% is...
egg white protein.
Poorly planned plant-based diets may not contain enough energy;...
high-quality protein; omega-3 fatty acids; vitamins B-12, D, and riboflavin; and minerals zinc, iron, calcium to meet a person's nutritional needs.
Blood urea nitrogen (BUN)
is a blood test often used to assess kidney function.
Thus, very young vegans may be unable to eat enough plant foods to meet their protein and energy needs. Therefore...
it is very important for parents or other caretakers to plan nutritionally adequate diets for vegetarian children and monitor the children's growth rates.
Furthermore, high intakes of red meat and processed meat may increase the risk of all-cause mortality. More research, however, is...
needed to clarify the tole of high-protein diets and red and processed meats in the risk of chronic disease.
During certain stages of life or physical conditions, however....
nitrogen intake and retention do not equal nitrogen losses.
There are many different types of plant-based vegetarian diets, including some that contain animal foods. A semi vegetarian (flextarian)....
usually avoids red meat but consumes other animal foods, including fish, poultry, eggs, and dairy products.
Children with PEM do not grow and are...
very weak, irritable, and vulnerable to dehydration and infections, such as measles, that can kill them.
In general, most plant foods provide less than...
3 grams of protein per ounce.
For example, a healthy man who is 5-feet, to inches tall and weighs 75kg should consume...
60 grams of protein to his RDA for the nutrient.
Dipeptides and tripeptides are
compounds that consist of two and three amino acids, respectively.
Peptides contain two or more amino acids. Most naturally occurring proteins are polypeptides....
comprised of 50 or more amino acids.
People suffering from marasmus avoid physical activity to...
conserve energy, and they are often irritable.
Additionally, people with PKU should not...
consume diet soft drinks and other foods and beverages containing the alternative sweetener aspartame because the sweetener is a source of phenylalanine
The presence of damaged villi can help confirm, the diagnosis of celiac disease. In cases in which a biopsy and other blood tests...
do not confirm celiac disease, genetic tests may be helpful. Genetic blood tests check for variations in genes that, when present, may indicate celiac disease.
If some protein is necessary for proper growth and good health can...
eating extra amounts of the nutrient make a person extra healthy or physically fit?
In 1990, scientists began the Human Genome Project, an...
effort to identify and sequence the approximately 23,000 genes that code for protein synthesis in human DNA. As a result, scientists discovered that people's food choices can affect their genes' expression.
Processed soybeans foods are good sources of...
essential amino acid content of the salad even further, add a small amount of hard-cooked egg, shredded cheese, or tofu to it.
Factors that contribute to high UUN levels:
excessive intake of protein, Increased breakdown of protein in the body
In addition, 39% of children with food allergies have...
experienced a significant allergic reaction.
Anaphylaxsis can be...
fatal, unless emergency treatment is provided. Genetics play a major role in the risk of food allergies; people who have family histories of allergies to specific foods or substances in foods are more likely to develop these conditions.
Plant foods contain little or no vitamin B-12, and there are...
few dietary sources of vitamin D other than fortified cow's milk.
Compared to the typical American diet, vegetarian diets provide more...
fiber, phytochemicals, folic acid (a B vitamin), vitamins E and C, and the minerals potassium and magnesium.
Meat, fish, poultry, eggs, and milk/milk products contain...
high quality proteins. Egg proteins generally rates very high for protein quality because it is easy to digest and has a pattern of essential amino acids that closely resembles that needed by humans.
High-protein diets are generally not recommended for healthy individuals. Such diets may lead to...
higher-than normal urinary losses of calcium. Urine calcium losses may be more likely to occur when people, particularly women, consume diets that contain more animal than vegetable proteins.
Liver cells remove NH2 from the amine component of glutamate, forming ammonia (NH3), a...
highly poisonous waste product. The liver can use the ammonia to make urea, a metabolic waste product that is released into the bloodstream
In comparison, the biological values of plant sources of protein are...
highly variable. For example, the biological value of whole soybeans is 96%, rice is 83%, tofu is 64%, whole-wheat flour is 64%, and whit flour is 41%.
Protein digestibility corrected amino acid score (PDCAAS)
is the most commonly used tool used to measure protein quality. Like biological value, Protein digestibility corrected amino acid score also takes into consideration the essential amino acid composition of the protein, as well as how ell the protein is digested and absorbed.
Deamination
is the process of removing the nitrogen-containing group (usually NH2) from an unneeded amino acid.
When the body is in a state of negative nitrogen balance....
it loses more nitrogen than it retains.
In the stomach, hydrochloric acid denatures food proteins, making them easier to digest. Denaturation does not....
kill a protein (because proteins are not living), but the process usually permanently alters the protein's shape and functions.
At one time, nutrition experts thought there were two types of PEM:
kwashiorkor and marasmus
Low-quality or incomplete protein
lacks or contains inadequate amounts of one or more of the essential amino acids. The human digestive tract does not digest low-quality protein sources as efficiently as foods containing high-quality protein.
When menu planning, people can combine a variety of....
legumes, grains, tree nuts, and seeds with vegetables to prepare dishes that provide adequate mixtures of the essential amino acids.
Some scientists caution that following such diets could cause malnutrition because of the limited food choices. More long-term, well-designed studies are...
necessary to determine whether there is a relationship between a gluten-free or GF/CF diet and ASD
The body uses amino acids to form nitrogen-containing compounds that are not...
proteins but have important physiological roles.
Vegetarians can also take a multiple vitamin/mineral supplement to...
provide dietary "insurance."
Furthermore, eating foods made from soybeans may...
reduce the risk of osteoporosis, cardiovascular disease, and certain cancers. More research is needed to determine the long-term health benefits of eating diets that contain soy products.
Primary structure
refers to the linear chain of amino acids liked by peptide bonds.
The tertiary structure
refers to the protein's final 3D form
People who suffer from asthma often develop breathing difficulties after consuming food treated with sulfites. Other sulfite-sensitive people report...
skin flushing (redness and warmth), hives, difficulty swallowing, vomiting, diarrhea, and dizziness after consuming foods that contain the compounds.
Diets that do not supply adequate amounts of essential amino acids can result in poor growth,...
slowed recovery from illness, and even death.
To increase the essential amino acid content of the salad even further, add a...
small amount of hard-cooked egg, shredded cheese, or tofu to it.
Although the body conserves nitrogen by recycling amino acids, each day...
some protein and nitrogen are lost. Urinary elimination of urea and creatinine accounts for most of the lost nitrogen.
Vegans can obtain vitamin B-12, vitamin D, iron, zinc, and many other micronutrients by consuming fortified foods such as...
soy and rice beverages, Red Star vegetarian nutritional yeast, and breakfast cereals.
However, vegetarian teenagers may have a higher risk of unhealthy weight control practices and eating disorders...
such as anorexia nervosa, than young people who eat meat.
The shape of a protein is important because it influences the compound's function in the body. Occasionally, an incorrect amino acid is introduced into....
the amino acid chain during the protein synthesis process.
Following digestion of proteins to amino acids, the amino acids are...
transported by specific carrier systems into absorptive cells. After entering the absorptive cell, the amino acids move into the capillary of the villus.
To make proteins, cells assemble the 20 amino acids in specific sequences according to the information provided by DNA. The connection between....
two amino acids is a peptide bond, a chemical link between the acid group of one amino acid and the amino group of another amino acid.
Allergic reactions generally occur within 30 minutes to a...
couple of hours after eating the offending food.
Although nearly all foods contain protein, no naturally occurring food is 100% protein. Protein comprises only....
about 20-30% of the weight of a piece of beef; 25% of the weight of drained, water-packed tuna fish; and only 12% of an egg's weight.
There is no cure for celiac disease, but persons with the condition can...
achieve and maintain good health by following a gluten-free diet very carefully.
Although most fruits and some kinds of vegetables are poor source of protein, they...
add appealing colors and textures as well as vitamins, minerals, and phytochemicals to plant-based meals.
Intuitively, the idea of eating more protein to improve one's health seems logical, but protein is no different from other nutrients. If a diet contains...
adequate amounts of protein, then eating more is not better.
Many American teenagers and young adults are...
adopting vegetarian diets. Switching from the typical Western diet to vegetarianism can be healthy practice for teens; vegetarian youth often eat more fruits and vegetables and less fat than their nonvegetarian peers.
nonessential amino acids
alanine, arginine, asparagine, aspartic acid, cysteine, glutamic acid, glutamine, glycine, proline, serine, tyrosine
The U.S. FDA requires manufacturers of...
alcoholic beverages that contain 10 or more mg sulfite/L to include a warning, such as "contains sulfites" on the product label.
In the United States, protein deficiency is uncommon, but people are suffering from...
alcoholism, anorexia, nervosa, or certain intestinal tract disorders are at risk of protein malnutrition.
Animal foods, such as beef, supply....
almost two-thirds of the protein in the American diet.
Some nutrition experts suspect that diets that supply a lot of animal protein are...
associated with osteoporosis, a condition characterized by thin bones that fracture easily.
Chronic intake of a very high-protein diet (over 35% of energy) may also...
be detrimental to kidney health, particularly in athletes
Severe PEM causes extreme weight loss and a condition called marasmus, which is...
commonly referred to as starvation. Obvious signs of marasmus are weakness and wasting.
Thus, low Urine urea nitrogen are....
commonly used as an indicator of low protein intake and malnutrition.
Cooked quinoa is often used as a cereal. After being processed, the quality of soy protein is...
comparable to that of most animal proteins.
Total vegetarians, including some vegan athletes can....
contain adequate amounts of the essential amino acids by eating processed soybean products and foods that combine complementary plant proteins.
Foods differ not only in the amount of protein they...
contain but also in their protein quality.
A high-quality or complete protein
contains all essential amino acids in amounts that support protein deposition in muscles and other, as well as supporting the growth of a young child.
In such cases, urea accumulates in the blood and causes toxicity. As kidney disease progresses, the amount of urea filtered through the kidneys...
continues to diminish. Thus, BUN levels continue to increase if the condition is untreated.
Phenylamine hydroxylase
converts the essential amino acid phenylalanine into the nonessential amino acid tyrosine.
Today, many supermarkets carry a variety of gluten-free foods. Although people with the condition can eat...
corn, rice, and soy products, these foods may be contaminated with gluten if they are processed in factories that also manufacture wheat products.
Furthermore, researchers used info to...
develop the science of nutritional genomics, which has two components: Nutrigenomics and Nutrigenetics
According to the World Food Program, one in every six children, nearly 100 million children in...
developing countries is underweight due to malnutrition.
Although the toddler may obtain adequate energy by consuming a traditional...
diet of cereal grains, the diet lacks enough complete protein to meet the youngster's high needs, and he or she soon develops signs of protein deficiency.
The concept of personalized nutrition, making....
dietary choices base on one's genetic makeup , is based on nutritional genomics. In addition to relying on traditional forms of health assessment, including height, weight, and blood pressure, health care professionals need to consider the influence that an individual's genetic background can have on dietary recommendations.
To calculate biological value, food scientists...
divide grams of nitrogen absorbed by grams of nitrogen retained.
In the US, approximately 8% of young children suffer from...
food allergies, with 30% of those children having multiple food allergies.
Specialized formulas are available for infants with PKU. As the children grow and mature...
fruits, vegetables, and special low-protein foods can be added to the formula diet.
If she fails to control the concentration of phenylalanine in her blood, she can...
give birth to a baby with severe birth defects, including a smaller-than-normal brain.
A food that is gluten-free is not necessarily nutrient dense and a healthy addition to the diet. There are many...
gluten-free potato chips cakes, and cookies that are high in simple sugars, fat, and sodium. Consumers choosing gluten-free foods should read nutrition labels carefully.
Celiac disease is also known as nontropical sprue and...
gluten-induced or gluten-sensitive enteropathy.
The older child, who is usually a toddler, is fairly....
healthy until abruptly weaned from his or her mother's milk to make way for the younger sibling.
Kidney disease is not the only cause of elevated BUN levels;...
heart disease, bleeding in the GI tract, and urinary tract obstructions can contribute to a high BUN.
After being absorbed, the amino acids travel to the liver via...
hepatic portal vein. The liver keeps some amino acids for its needs and releases the rest into the general circulation.
A person who is 80 years of age and needs to take several medicines daily to treat heart disease, breathing problems, and abnormally high fluid pressure in...
his or her eyes may think it is more important to purchase costly prescription medications than nutritious foods.
A person with elevated BUN due to kidney disease is often advised to eat less protein so that.....
his or her kidneys have less work to do. A registered dietitian nutritionist (RDN) can counsel patients who have high BUN levels to ensure they are consuming enough protein but not too much.
Essential amino acids
histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine
As a result of the immune response, the....
individual experiences typical signs and symptoms of food allergy hives, red raised bumps that usually appear on the skin; swollen or itchy lips; a scaly skin rash (eczema); difficulty swallowing; wheezing and difficulty breathing; and abdominally pain, vomiting, and diarrhea.
Nutritional genomics is a dynamic field, and the results of research in this field can...
influence the work of health care professionals.
Chemical reactions called deamination and transamination are...
involved in the synthesis of amino acids, which occurs primarily in the liver.
Biological value (BV)
is a measure of protein quality based on how well and how quickly the body converts foods protein into body tissue proteins.
The amino acid composition score
is a measure of the amount of each essential amino acid in a gram of the food protein divided by the "ideal" amount of each essential amino acid in a reference protein (usually egg white protein).
Dehydration
is a potentially life-threatening condition in which the body's water level is too low.
Phenylketonuria or PKU
is a rare genetic metabolic disorder that affects about 1 in every 10,000 or 15,000 infants in the U.S. The condition usually occurs when cells are unable to produce the enzyme phenylalanine hydroxylase or produce an inactive form of it.
Anorexia nervosa
is a serious psychological disorder that can result in starvation and death.
Protein efficiency ratio (PER)
is a third measure of protein quality. Protein efficiency ratio is determined by measuring the weight gain of a growing laboratory animal that consumes a known amount of a specific type of protein. The weight gain of the animal is then compared against weight gain following consumption of a reference protein, most often a milk protein (casein).
Celiac disease
is an autoimmune disorder that results in poor absorption of nutrients (malabsorption) in the small intestine.
sickle cell anemia
is an inherited condition characterized by abnormal hemoglobin. If the hemoglobin-producing DNA codes for the insertion of a particular wrong amino acid in two of hemoglobin's four polypeptide chains, the resulting protein is defective and does not function correctly.
Phenylalanine
is essential for growth and development; therefore, pediatricians often recommend that infants with PKU consume a small amount of the amino acid, which most are able to do without any side effects.
Wasting
is the loss of organ and muscle proteins as the body tears down these tissues to obtain amino acids for energy metabolism.
The essential amino acids that are relatively low amounts are referred to as...
limiting amino acids, because they reduce the protein's ability to support growth, repair, and maintenance of tissues.
An important function of certain proteins in blood is to...
maintain proper fluid balance within cells and blood vessels, as well as between cells.
The body uses amino acids from foods to replace the lost nitrogen. Normally, an adult's body maintains its proteins content by...
maintaining nitrogen balance or nitrogen equilibrium, that is, balancing nitrogen intake and protein turnover with losses.
People with the disorder are advised to undergo frequent blood tests to...
make sure they are maintaining a healthy concentration of phenylalanine in their bodies.
Every organism synthesizes proteins that are unique to that specific organism. The human body...
makes proteins by following information coded in DNA, or deoxyribonucleic acid, the hereditary material in a cell's nucleus that are in genes.
As such, it may be difficult for them to eat enough plants foods to...
meet their relatively high protein and other nutrient requirements.
Sulfites are a group of sulfur-containing compounds that result from the...
metabolism of certain amino acids.
When the dipeptides and tripeptides contact the....
microvilli of villi, enzymes within the microvilli can break down di- and tripeptides into amino acids. Thus, amino acids are the end products of protein digestion.
There is great variability in a child's degree of ASD; some children experience very...
mild symptoms that are only noticeable to parents and close caregivers.
Although research findings indicate that it is not...
necessary to consume all essential amino acids during each meal for the body to utilize them for growth, certain plant-based recipes ensure that these compounds are consumed at one time.
Humans digest animal proteins to a greater extent than plant proteins. Therefore, vegetarians may...
need to increase their protein intakes by 10% to compensate.
Autism spectrum disorders (ASDs), often simply simply called autism are....
neurodevelopmental disorders characterized by deficits in social interaction and verbal and non verbal communication, and by repetitive behaviors or interests.
Amino acid derivatives
nitrogen-containing compounds that are not proteins but have important physiological roles.
High-protein diets are generally not recommended for healthy individuals. Such diets may lead to higher-than....
normal urinary losses of calcium. Urine calcium losses may be more likely to occur when people, particularly women, consume diets that contain more animal then vegetable proteins.
Children with this condition also experience poor growth due to....
nutrient malabsorption and protein malnutrition.
Commercially prepared vegetarian foods that substitute meat, fish, and poultry items are...
often available in the frozen-food section of supermarkets. These vegetarian products can look and taste like their nonvegetarian counterparts, but they may be lower in saturated fat. Such foods include soy-based sausage patties or links, soy hot dogs, veggie burgers and soy crumbles that resemble beef.
Other treatments often used during food preparation also denature proteins, including whipping or exposing them to alcohol or acid. Wine, for example, is...
often used in marinades because the alcohol it contains denatures proteins in meat, helping tenderize it.
Individuals with low incomes, especially those who are elderly, are also at risk of protein deficiency. Many...
older adult Americans have limited incomes and must make difficult choices concerning their expenses.
To diagnose PKU, physicians generally rely on a simple blood test that is conducted....
on infants soon after birth. In the US all states require newborns to undergo blood testing for PKU and several other treatable inherited diseases.
In many cultures, traditional foods already combine complementary proteins. Rice and beans as...
one example contain complementary proteins as do rice and tofu a soy product.
Registered dietitian nutritionists now face the...
opportunity and challenge to make genetically driven dietary recommendations.
Vegan
or total vegetarian, eats only plant foods.
Furthermore, some mineral are more available from animal foods than from plant foods. Plants often contain....
phytochemicals that interfere with the body's absorption of minerals, particularly iron, zinc, and calcium
In addition, vegetarian diets often supply less saturated fat than diets that include animal foods. In general....
plant foods have energy density; they add bulk to the diet without adding a lot of calories.
Tree nuts include walnuts, cashews, and almonds; legumes are...
plants that produce pods that have a single row of seeds, such as peas, peanuts, lentils, and the many varieties of beans, including soybeans.
When assembly of the new protein has been completed, the...
polypeptide acid chain coils and folds into a three-dimensional shape that is characteristic of that particular protein.
Sulfites can be naturally in food, but the compounds are often added to wines, fruits, vegetables, and shellfish to...
prevent spoilage or preserve flavors.
The structure of a protein can be specified at the...
primary, secondary, tertiary, and quaternary structure.
While some amino acids must be consumed in the diet, not all amino acids have to be supplied through dietary sources. Protein turnover the...
process of breaking down old or unneeded proteins into their component amino acids and recycling them to make new proteins, occurs constantly within cells.
Blood tests and intestinal biopsies are often used to diagnose celiac disease. Intestinal biopsy involves...
removing tiny pieces of tissue from the small intestine. The tissue samples undergo microscopic examination to evaluate the condition of the villi.
Negative balance occurs during starvation, serious illness, and severe injuries. Recovery from the illness or injury involves....
replacing the protein that was lost (refeeding).
Even though the affected person's food intake may be nutritionally adequate, undernutrition...
results because his or her intestinal tract lacks healthy villi.
However, children and adults with the disorder need to avoid foods that are...
rich sources of phenylalanine, such as nuts, milk products, eggs, meats, and other animal foods.
Autism is four to five times more common in boys than girls. Although environmental factors probably play a...
role in the condition's development, genetic factors are also involved.
Soon after the polypeptides enter the small intestine, the pancreas...
secretes protein-splitting enzymes, including trypsin and chymotrypsin
In severe cases.....
sensitive people who are exposed to food allergens can develop anaphylactic shock, a serious drop in blood pressure that affects the whole body.
In recent years, gluten sensitivity has become recognized as a...
separate condition from celiac disease. Compared to celiac disease, people with a gluten sensitivity do not have damage to the small intestine.
Examples of such amino acid derivatives include creatine; melanin; and regulatory amines such as...
serotonin, epinephrine, and histamine.
Wheat germ, however, is a rich source of lysine. Legumes are low in methionine. Seeds such as....
sesame seeds and sunflower seeds are generally low in lysine.
Individuals who are sensitive to glutens may test negative for celiac disease, yet they report....
signs and symptoms that are similar to celiac disease after consuming gluten.
In countries of unrest, protein-energy malnutrition (PEM) affects people whose diets lack...
sufficient protein as well as energy. The failure to consume adequate amounts of protein and energy also results in vitamin and mineral deficiencies.
Impoverished children in Asia and Africa are most likely to develop PEM, and...
the effects of PEM are especially devastating for the very young.
Blood proteins help counteract the effects of blood pressure by attracting the...
the fluid and returning it to the bloodstream.
Gluten contains the peptide gliadin. In cases of celiac disease, gliadin enters...
the intestinal mucosa and activates the immune system, which inflames or destroys villi.
Excess amino acid or protein intake can lead to dehydration because...
the kidneys need more water to dilute and eliminate the toxic waste products of amino acid metabolism in urine.
In most instances, tryptophan, threonine, lysine, and the sulfur-containing amino acids methionine and cysteine are...
the limiting amino acids in foods.
Although any food protein has the potential to cause an allergic reaction in a susceptible person...
the most allergenic proteins are in cow's milk, effs, peanuts, and other nuts, wheat, soybeans, fish, and shellfish.
Vegan who breastfeed their infants may produce milk that is deficient in vitamin B-12, particularly if...
the mothers' diets lack the vitamin. Infants of these mothers have a high risk of developing severe developmental delays associated with neurological damage, especially when breast milk is their only source of vitamin B-12.
Thus, individuals with PKU should follow...
the phenyl restrictive diet and ensure adequate intake of tyrosine, which becomes conditionally essential in an individual with PKU.
The PDCAAS is calculate by multiplying the amino acid composition score of...
the protein by the protein by the protein's digestibility score. Most animal proteins, as well as soy protein, have a PDCAAS of 1.0.
If these children survive, their growth may be permanently stunted and....
their intelligence may be lower than normal because malnutrition during early childhood can cause permanent brain damage.
After an amino acid undergoes deamination, the carbon skeleton that remains can be...
used for energy or converted to other compounds, such as glucose. Muscle cells can deaminate certain amino acids and use their carbon skeletons for energy
During starvation ( a state in which the body lacks food energy and/ or protein), the level of protein in blood decreases, and as a result, some...
water leaks out of the bloodstream and enters spaces between cells. The resulting accumulation of fluid in tissues is called an edema.
Daily nitrogen losses also occur as nails and hair grow and...
when the outermost layer of the skin and cells from the intestinal tract are shed.
During starvation, levels of these proteins decline, resulting in edema...
which can make the protein-deficient child look plump and overfed instead of thin and undernourished.
Treatment of food allergies involves strict avoidance of the offending foods. Parents or caregivers of young children....
with food allergies should read food labels carefully to check for allergens listed among ingredients.
In 2013-2014, protein comprised about 15% of the typical adult American's total energy intake for a day. For healthy adults, this level of consumption is...
within the Acceptable Macronutrient Distribution Range (AMDR), which is 10 to 35% of energy from protein.
