Indirect Calorimetry

A Raman and D A Schoeller, University of Wisconsin-Madison, Madison, WI, USA 2005 Elsevier Ltd. All rights reserved. All living organisms require a source of energy for survival. Among animals, this energy is provided in the form of chemical energy in the nutrients they consume, which are converted to other forms of energy through respiration. This conversion is subject to the same laws of thermodynamics that govern all energy systems. The first law of thermodynamics states that energy can...

Effects of Dietary ALA Compared with Long Chain n3 Fatty Acid Derivatives on Physiologic Indexes

Several clinical and epidemiologic studies have been conducted to determine the effects of long-chain n-3 PUFAs on various physiologic indexes. Whereas the earlier studies were conducted with large doses of fish or fish oil concentrates, more recent studies have used lower doses. ALA, the precursor of n-3 fatty acids, can be converted to long-chain n-3 PUFAs and can therefore be substituted for fish oils. The minimum intake of long-chain n-3 PUFAs needed for beneficial effects depends on the...

Physiological Ketosis

Physiological hyperketonemia is found in the suckling neonate (high-fat diet of the milk Figure 1), postexercise (depletion of hepatic glycogen reserves), and after prolonged fasting (more than 24 h Figure 7). All these situations have in common a low hepatic carbohydrate status (depletion of glycogen and or activation of gluconeogenesis) and therefore from a physiological standpoint one would expect an increased rate of ketogenesis. Comparison of the factors which can influence ketogenesis in...

Dietary Sources

Carotenoids cannot be synthesized by humans therefore they must be obtained from dietary sources. These are primarily highly pigmented red, orange, and yellow fruits and vegetables. The caro-tenoid lycopene is red however, not all red fruits and vegetables contain lycopene. For example, the red in strawberries, apples, and cherries is a result of their anthocyanin content whereas, tomatoes, watermelon, and pink grapefruit derive their red color from lycopene. The carotenoids -carotene,...

Oral Glucose Tolerance Test

In the absence of an obvious elevation in fasting or random plasma glucose levels, the diagnosis of diabetes mellitus can be made with an oral glucose tolerance test (OGTT). This involves, for the non-pregnant adult, the ingestion of a solution containing 75 g of glucose over 5 min, with a measurement of baseline and 2-h plasma glucose. The criteria used to diagnose diabetes are listed in Table 1. The diagnosis can be made if the fasting glucose exceeds 7.0 mmol l or the 2-h value exceeds 11.1...

Examples of Specialist Roles in Dietetics Renal Dietetics

Renal dietitians are usually attached to specialized renal units and are an integral part of the team involved in the treatment of people suffering from varying degrees of renal impairment, whether acute or chronic. In the United States, there is a legal requirement related to funding of patient care that states that a qualified dietitian must be part of the professional team that develops long- and short-term care plans for renal patients. The dietitian, together with the nephrologist, has...

Practical Management of Eating Difficulties

Anorexia (loss of appetite) is often associated with other eating difficulties, such as nausea, taste changes, and constipation, and addressing these problems may improve the patient's appetite. Pain may also contribute to anorexia, and regular analgesia for pain may in turn help improve appetite, as may dietary alterations (Table 2). For patients who have severe anorexia, an appetite stimulant should be considered, such as dexamethasone, medroxyproes-terone acetate, or megestrol acetate....

Pathophysiology and Symptoms

Malabsorption can occur when any of the several steps in nutrient digestion, absorption, and or assimilation are interrupted see Table 1 for a list of congenital defects in nutrient assimilation. Carbohydrate malabsorption can occur, for instance, when intestinal disaccharidases are reduced in concentration at the enterocyte. The brush border membrane produces four disaccharidases that are important in carbohydrate digestion. These enzymes are sucrase-isomaltase, maltase-glucoamylase,...

Dynamics of Energy Balance with Overfeeding and Underfeeding Figure

To understand the dynamic aspect of energy balance while overfeeding is of the utmost important, since as mentioned previously the system is not invariant. Decreased En relative to E requirement Figure 9 Dynamic change in energy balance following a step steady increase (A) overfeeding (or decrease) (B) underfeeding in energy intake. The time required to reach a new equilibrium in energy balance is very long (years) and depends upon the initial energy imbalance, the magnitude of adaptation of...

Energy Imbalance and Body Weight

Positive energy balance leads to body weight gain and negative energy leads to body weight loss. There is no fixed relationship between these two variables so that relatively small energy retention can be accompanied by large body weight gain and vice versa. The confounding factor is the associated water storage. Long-term fluctuations in fat stores will be reflected in body weight. There is a difference in the energy value of fat mass and fat-free mass, the latter including the glycogen-water...

Macronutrient Balance Energy Balance and Storage

Since macronutrients (carbohydrate, fat, protein, and alcohol) are the sources of energy, it is logical to consider energy balance and macronutrient balance together as the opposite side of the same coin. There is a direct relationship between energy balance and macronutrient balance, and the sum of individual substrate balance (expressed as energy) must be equivalent to the overall energy balance. Thus exogenous carbohydrate carbohydrate oxidation exogenous protein protein oxidation lipid...

Body Composition Applications During Aging

During the adult life span, body weight generally increases slowly and progressively until about the seventh decade of life, and thereafter, declines into old age. An increased incidence of physical disabilities and comorbidities is likely linked to aging-associated body composition changes. Characterization of the aging processes has identified losses in muscle mass, force, and strength, which collectively are defined as 'sarcopenia.' Little is known about the overall rate at which sarcopenia...

Unilocular And Multilocular Lipids Drops Synonym

Acids see Electrolytes Acid-Base Balance G Fr hbeck and J Gomez-Ambrosi, Universidad de 2005 Elsevier Ltd. All rights reserved. The role of white adipose tissue (WAT) in storing and releasing lipids for oxidation by skeletal muscle and other tissues became so firmly established decades ago that a persistent lack of interest hindered the study of the extraordinarily dynamic behavior of adipocytes. However, disentangling the neuroendocrine systems that regulate energy homeostasis and adiposity...

Postoperative Dysphagia

Oropharyngeal dysphagia can occur in the postoperative setting for a number of reasons. Procedures involving the upper aerodigestive tract for either benign or malignant disease can result in varying degrees of dysphagia with or without aspiration due to alteration in the anatomical mechanism of swallowing. In addition, procedures in the neck can be complicated by inadvertent injury to the aerodigestive tract or to the nerves innervating the muscles of deglutition, resulting in dysphagia. The...

Genetics

Family studies and research in twins indicate that about 50 of the variation of serum cholesterol concentrations in the general population can be explained by genetic polymorphisms. Presumably this variation is related to factors that regulate lipo-protein concentrations. In some cases, specific genetic defects are severe, resulting in marked changes in lipoprotein concentrations. When this occurs, the affected individual is said to have a mono-genic disorder. In other cases, multiple genetic...

Antiinflammatory Aspects of n3 Fatty Acids

Many experimental studies have provided evidence that incorporation of alternative fatty acids into tissues may modify inflammatory and immune reactions and that n-3 fatty acids in particular are potent therapeutic agents for inflammatory diseases. Supplementing the diet with n-3 fatty acids (3.2 g EPA and 2.2 g DHA) in normal subjects increased the EPA content in neutrophils and mono-cytes more than sevenfold without changing the quantities of AA and DHA. The anti-inflammatory effects of fish...

Prevention of Dehydration

Dehydration resulting from nondisease causes can be easily prevented provided that people are inclined to drink and have access to cool, safe sources of fluids. Drink flavoring, beverage temperature, and sodium chloride content are important promoters of fluid intake in active children. Education of athletic coaches, the general public, and health care providers is necessary to increase Table 6 Fluid replacement Summary of recommendations of the American College of Sports Medicine It is...

Hyperglycemia and the Glycemic Index

In contrast to the numerous processes that protect against blood glucose falling too low, there is only one that protects the body from hyperglycemia the release of insulin into the blood in response to the ingestion of food. Plasma insulin concentration, although neither its rate of increase nor its effectiveness (which depend on intrinsic physiology of the B cells and peripheral insulin sensitivity, respectively), is in large part determined by the increase in arterial blood glucose...

The Fetus

Iodine deficiency of the fetus is the result of iodine deficiency in the mother (Figure 2). The condition is Table 1 Spectrum of Iodine Deficiency Disorders Mental deficiency, deaf mutism, spastic Retarded mental and physical development Retarded mental and physical development Increased susceptibility to nuclear radiation Reproduced with permission from Oxford University Press and the World Health Organization, WHO UNICEF ICCIDD (2001). Reproduced with permission from Oxford University Press...

Hunger Physiological Determinants

Stomach distension and the detection of macro-nutrients such as fat or protein within the gut are all powerful satiety cues. They bring a meal to an end and for a time inhibit further consumption. Eventually, hunger again prevails and food intake follows. The flux between hunger and satiety is episodic and underpins the expression of our eating behavior throughout the day. However, it is not just the absence of episodic satiety cues (e.g., stomach distension and intestinal or absorbed...

Complex Causation

Although pellagra in dogs and humans usually responds well to supplements of pure niacin, there are several further strands to the story that complicate the idea that all the characteristics and manifestations of pellagra can be explained as the result of a simple dietary deficiency of a single water-soluble factor (i.e., vitamin) identified as the molecule niacin. First, it soon became clear that the total niacin content of different foods, as measured by chemical analysis, was not necessarily...

PMS and Dietary Factors

Various reports, many of a preliminary nature, or based on clinical experience, suggest that women suffering from PMS consume more sugar, refined carbohydrate, and dairy products and less fiber, B complex vitamins, iron, zinc, and magnesium than normal women. Carbohydrate-rich meals have been shown to improve mood in women with premenstrual depression. The reason for this has been indicated in animal studies The availability of tryptophan to the brain increases following such meals. As...

Anthropometric Techniques

Anthropometric indices used to measure fat patterning include skinfold thicknesses, circumferences, sagittal diameter, and ratios such as Figure 2 Cross-sectional images of the abdomen obtained by MRI. (A) Small subcutaneous fat area and enlarged visceral fat area. (B) Small visceral fat area in comparison with subcutaneous fat depot. Figure 2 Cross-sectional images of the abdomen obtained by MRI. (A) Small subcutaneous fat area and enlarged visceral fat area. (B) Small visceral fat area in...

Muscle Tone and Positioning

It is important to understand the influences of muscle tone and proper positioning on the ability to eat safely and efficiently in this population. Increased or decreased muscle tone contributes to difficulty preserving a patent airway, compromised self-feeding skills, poor rib cage expansion and esophageal motility, and difficulty in maintaining a stable supported base for seating. Fluctuating muscle tone leads to involuntary movements and limited postural stability. Despite the type of muscle...

Body Mass Index BMI

The body mass index (BMI weight kg height m2) continues to be the most commonly used index of weight status, where normal weight is a BMI 18.5-25.9 kg m2 overweight is a BMI 25.0-29.9 kg m2 and obese a BMI > 30.0 kg m2. BMI is a commonly used index of fatness due to the high correlation between BMI and percent body fat in children and adults. The prediction of percent body is dependent on age (higher in older persons), sex (higher in males), and race (higher in Asian compared to African...

Complementary Feeding

K G Dewey, University of California Davis, Davis, CA, USA 2005 Elsevier Ltd. All rights reserved. Complementary feeding has been defined as .the process starting when breast milk alone is no longer sufficient to meet the nutritional requirements of infants, and therefore other foods and liquids are needed, along with breast milk. In the past, such foods were often called 'weaning foods.' However, the term 'complementary foods' is preferred because weaning implies the cessation of breastfeeding,...

Insulin Resistance and Hyperinsulinemia

'Insulin resistance' refers to the phenomenon of insensitivity of the cells of the body to insulin's actions. Different tissues may have different insulin sensitivities. For example, adipose tissue may be more sensitive to insulin than muscle tissue, thus favoring the deposition of fatty acids in adipose tissue and diminished fatty acid oxidation in muscle. Insulin resistance is usually associated with hyper-insulinemia. Hyperinsulinemia is an independent marker that predicts the development of...

Alcohol and Facial Flushing

Genetic variations in ADH and ALDH may explain why particular individuals develop some of the pathologies of alcoholism and others do not. For example, up to 50 of Orientals have a genetically determined reduction in ALDH2 activity ('flushing' phenotype). As a result, acetaldehyde accumulates after ethanol administration, with plasma levels up to 20 times higher in people with ALDH2 deficiency. Even small amounts of alcohol produce a rapid facial flush, tachycardia, headache, and nausea....

Effects on the Cardiovascular System

Caffeine produces a direct stimulation of myocardial tissue leading to an increase in the rate and force of contraction. This direct cardiac effect can be inhibited by a depressant effect on the heart via medullary vagal stimulation. These opposing effects may explain why bradycardia, tachycardia, or no change can be observed in individuals receiving similar doses of caffeine. The traditional clinical view that caffeine induces arrhythmias in humans has not been confirmed by controlled...

Low Carbohydrate Diets

The recent trend of weight loss diets promotes some level of carbohydrate restriction and increased protein consumption. Some examples are Dr Atkins New Diet Revolution, The South Beach Diet, and The Carbohydrate Addict's Diet. This dietary advice is contrary to that proposed by governmental agencies (US Department of Agriculture Department of Health Services, National Institutes of Health) and nongovernmental organizations (American Dietetic Association, American Heart Association, American...

Dietary Cholesterol and Plasma Cholesterol

The effect of dietary cholesterol on plasma cholesterol levels has been an area of considerable debate. In 1972, the American Heart Association recommended that dietary cholesterol intake should average less than 300mgperday as part of a 'heart-healthy,' plasma cholesterol-lowering diet. Since that initial recommendation, a number of other public health dietary recommendations in the United States have endorsed the 300 mg daily limit. Interestingly, few dietary recommendations from other...

Dietary Cholesterol Intake Patterns

Dietary cholesterol intakes in the United States have been declining, from an average of 500 mg per day in men and 320 mg per day in women in 1972 to levels in 1990 of 360 mg per day in men and 240 mg per day in women. This decline is due in part to dietary recommendations to the US public to reduce total and saturated fat intake and to reduce dietary cholesterol daily intake to less than 300 mg and in part from the increased availability of products with reduced fat and cholesterol content....

Type II or Familial Hypercholesterolemia

Familial hypercholesterolemia (FH) is an autosomal dominant disorder characterized by elevation of plasma LDL cholesterol levels. Mutations at the LDL receptor gene locus on chromosome 19 are Table 4 Classification of hyperlipidemias according to Fredrickson Type Plasma cholesterol Genetic disorder triacylglycerol fraction(s) affected risk Normal to elevated Very elevated Chylomicrons Normal or elevated Elevated Normal or elevated Very elevated Apo C-II deficiency High Familial...

Dietary Cholesterol

All dietary cholesterol is derived from animal products. The major sources of cholesterol in the diet are egg yolks, products containing milk fat, animal fats, and animal meats. Many studies have shown that high intakes of cholesterol will increase the serum cholesterol concentration. Most of this increase occurs in the LDL cholesterol fraction. When cholesterol is ingested, it is incorporated into chylomicrons and makes its way to the liver with chylomicron remnants. There it raises hepatic...

Age and Risk Factor Profile

A few studies have indicated that subjects already at high risk of coronary disease experience a greater beneficial effect of drinking alcohol moderately conversely, only in those with a high risk level is coronary heart disease prevented. Hence, the large Nurses Health Study found that the J-shaped relation was significant only in women older than 50 years of age, whereas younger women who had a light alcohol intake did not differ from abstainers with regard to mortality. Fuchs et al. found...

The Observational View of Dietary Antioxidants

Cancer and cardiovascular disease (CVD) are the two leading causes of death worldwide, diabetes mellitus is reaching epidemic proportions, and dementia and maculopathy are largely untreatable irreversible disorders that are increasingly common in our aging population. The prevalence and standardized mortality rates of these diseases vary considerably between and within populations. Mortality from CVD varies more than 10-fold amongst different populations, and incidences of specific cancers vary...

Health Effects of Carbohydrates

Carbohydrates are stored in the human body as glycogen mainly in the liver and muscle. The human body has a limited storage capacity for carbohydrates compared to fat. The total amount of carbohydrates stored in tissues and circulating in the blood as glucose is approximately 7.56 MJ (1800 kcal). Diets high in carbohydrate ensure adequate glycogen storage available for immediate energy utilization. Carbohydrates are the preferred energy source for the human brain and have an important role in...

Exogenous Cholesterol Transport

Cholesterol is absorbed in the unesterified state, whereas the cholesterol secreted into the lymph is 70-80 esterified. This esterification process generates a concentration gradient of free cholesterol within the mucosal cell that may facilitate absorption rates. Cholesterol is esterified in intestinal mucosal cells by acyl-coenzyme A cholesterol acyl-transferase-2 to form cholesteryl esters, which are secreted from the basolateral surface of the entero-cyte as part of the chylomicrons. At...

Tissue Uptake and Storage

The body pool of cholesterol is approximately 145 g, with one-third of this mass localized in the central nervous system. The remainder of the metabolically active cholesterol pool exists in the plasma compartment (7.5-9 g) and as constituents of body tissues. In humans, tissue cholesterol levels are relatively low, averaging 2 or 3 mg g wet weight. Little information exists regarding changes in hepatic and extrahepatic tissue cholesterol concentrations with changes in dietary cholesterol...

Regulation of Synthesis

The rate-limiting enzyme in cholesterol biosynthesis is 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, a microsomal enzyme that converts HMG-CoA to mevalonic acid in the polyisoprenoid synthetic pathway. Peripheral tissue cholesterol synthesis is much less responsive to regulatory factors compared to the liver, which is controlled by a variety of dietary, hormonal, and physiological variables. Studies indicate that endogenous cholesterol synthesis is significantly increased in...

Major Dietary Sources

The major sources of cholesterol in the diet are eggs, meat, and dairy products. A large egg contains approximately 215 mg of cholesterol and contributes approximately 30-35 of the total dietary cholesterol intake in the United States. Meat, poultry, and fish contribute 45-50 , dairy products 12-15 , and fats and oils 4-6 . In the United States, the range of dietary cholesterol intake is 300-400 mg per day for men and 200-250 mg per day for women thus, for much of the population the national...

Potential Mechanisms Indicating a Role in the Etiology of Coronary Heart Disease

The mechanism for risk reduction and the fiber components responsible need resolution. Elevated plasma total and low-density lipoprotein (LDL) cholesterol concentrations are established risk factors for coronary morbidity and mortality. There are abundant human and animal data showing that diets high in soluble fiber lower plasma cholesterol. One population study has shown a significant negative relationship between viscous (soluble) fiber intake and carotid artery atherogensis as measured by...

Ldl Hdl and atherosclerosis

Membrane function is compromised if it contains either too much or too little cholesterol. Epidemio-logical studies have classified raised plasma cholesterol levels as a risk factor for atherosclerosis, and it is one of the more important predictors of coronary heart disease (CHD). Elevated plasma cholesterol concentration (hypercholesterolemia) is associated with an increased concentration of LDL, owing to either an increased rate of LDL formation or a decrease in the rate at which they are...

Endothelial dysfunction

Decrease in the production, release, or action of NO may lead to enhanced expression of adhesion molecules and chemotactic factors at the endothelial surface. The exact nature of endothelial dysfunction is unknown, although possibilities include a decreased expression of NO synthase, imbalance between the production of endothelium-derived constricting and relaxing factors, production of an endogenous NO synthase inhibitor, and overproduction of oxygen-derived free radicals including O2. The...

Eicosanoid Metabolism and Biological Effects of n6 and n3 Fatty Acids

When humans ingest fish or fish oil, the ingested EPA and DHA partially replace the n-6 fatty acids (especially AA) in cell membranes, particularly those of platelets, erythrocytes, neutrophils, monocytes, and liver cells. Because of the increased amounts of n-6 fatty acids in the Western diet, the eicosanoid metabolic products from AA, specifically prostaglandins, thromboxanes, leukotrienes, hydroxy fatty acids, and lipoxins, are formed in larger quantities than those formed from n-3 fatty...

Total Saturated Fat Content of Diets

Using statistical techniques, results from independent experiments have been combined to develop equations that estimate the mean change in serum lipoprotein levels for a group of subjects when carbohydrates are replaced by an isoenergetic amount of a mixture of saturated fatty acids. The predicted changes for total LDL and HDL cholesterol and triacylglycerols are shown in Figure 1. Each bar represents the predicted change in the concentration of that particular lipid or lipoprotein when a...

Effect of trans Fatty Acids on Plasma Lipoproteins

Raised plasma concentrations of low-density lipopro-tein (LDL) are considered to be a risk factor for coronary heart disease (CHD) in contrast, reduced concentrations of high-density lipoprotein (HDL) are considered to increase risk. It therefore follows that to help protect against CHD, diets should ideally help to maintain plasma concentrations of HDL cholesterol and to lower those of LDL cholesterol. Dietary factors that raise LDL and lower HDL concentrations would be considered to be...

Guide for Separating Food Folklore Facts from Fiction in Clinical Situations and A Practical Example

For summarizing and evaluating food folklore involving diet-health relationships, health professionals need to not only evaluate the evidence but also use their clinical judgment and communications skills to relate this to clients or patients. How can food folklore be evaluated in discussions with laypeople and in counselling situations The strategies are similar to those employed in research and in more formal evidence-based reviews, but contextual realities require tailoring of the approach....

Edible Plants and Phytochemicals

Because their consumption is known to enhance health, vegetables, fruits, cereal grains, nuts, and seeds are the most widely researched functional foods. The health benefits of a plant-based diet are usually attributed to the content of fiber and of a variety of plant-derived substances (phytonutrients and phytochemicals) with antioxidant, enzyme-inducing, and enzyme-inhibiting effects. Some phyto-chemicals may also exert their health effects by modifying gene expression. Carotenoids, for...

Pathophysiology of Stone Formation

There are three kinds of gall stone cholesterol, black pigment, or brown pigment stones. Cholesterol stones constitute 75-90 of all gall stones. They are composed purely of cholesterol or have cholesterol as the major chemical constituent. Most cholesterol gall stones are of mixed composition. Pigmented stones get their color and their name from precipitated bilirubin. Increased production of unconjugated bilirubin causes black pigmentation. Formation of black pigment stones is typically...

Benefits of Low Glycemic Index Carbohydrates on Cardiovascular Disease Risk Factors

High glycemic index foods induce postprandial hyperinsulinemia, which is a powerful predictor for metabolic risk factors and CVD in epidemiological studies. Both cross-sectional and prospective population studies have shown favorable lipid profiles in association with high carbohydrate diets. Initially, these benefits were attributed to a high fiber content. However, when the glycemic index is controlled for, it is the low glycemic index diets rather than high fiber content that have the...

Contemporary Low Calorie Carbohydrate Restricted Diet

In view of the well-recognized link between insulin resistance syndrome, hyperuricemia, and gout, a diet emphasizing reduced calorie intake with moderate restriction of carbohydrates and liberalization of protein and unsaturated fat consumption has been espoused for patients with gout. Low-purine foods are often high in both carbohydrate and saturated fats these foods tend to further decrease insulin sensitivity, thereby contributing to even higher levels of insulin, glucose, triglycerides, and...

Homocysteine and Vascular Disease

The current interest in homocysteine is primarily related to its recognized status as an independent risk factor for cardiovascular, cerebrovascular, and peripheral vascular disease. This homocysteine theory of vascular disease comes directly from a seminal observation made by Kilmer McCully. In the early to mid-1960s, it was recognized that a prominent characteristic of patients with homocystinuria caused by defects in cystathionine -synthase were very high elevations of both homocysteine and...

Other Dietary Approaches for the Prevention and Management of CVD

Very Low-Fat High-Carbohydrate Diet and High-Protein Low-Carbohydrate Diet When considering diets very low in fat and high in carbohydrates ('very low-fat' diets), it is important to separate the effects of the composition of the diet from confounding factors associated with intentional weight loss. For the purposes of this discussion, a very low-fat diet will be defined as less than 15 of energy as fat. Consumption of a very low-fat diet without a decrease in energy intake frequently decreases...

Dietary Factors with Limited or Uncertain Effect on Blood Pressure

Evidence from observational studies and several clinical trials suggests that increased fiber intake may reduce blood pressure. A meta-analysis documented that supplemental fiber (average increase of 14g day) was associated with net systo-lic diastolic reductions of 1.6 2.0 mmHg, respectively. Still, high-quality epidemiologic studies and clinical trials are needed before one can recommend increased fiber intake as a means to lower blood pressure. Evidence that increased calcium intake might...

Adipose Tissue Hormones

The adipose tissue secretes different hormones called adipocytokines. Their secretion seems to vary in relation to the amount of adipose tissue accumulated, although the exact mechanism is not known. During profound weight loss, as in anorexia nervosa, there is a marked decrease in the adipose tissue mass with the typical changes in adipocytokines secretion that occur in these circumstances. One of the most studied adipocytokine changes is decreased leptin secretion. Increased fat mass stores...

Obesity Associated with Recognized Medical Condition

There are conditions in which obesity is part of a recognized genetic defect, clinical syndrome, or acquired pathological condition (Table 2). Together, these conditions account for only a very small Table 2 Specific conditions associated with obesity in childhood Inherited syndromes associated with childhood obesity Inherited syndromes affecting mobility Inherited disorders of growth Chromosomal abnormalities Single gene defect affecting leptin metabolism Autosomal dominant Autosomal recessive...

Obesity

Obesity is not inevitable in Down's syndrome, but it is common. Obesity in children with Down's syndrome has been reported from different cultures and different ethnic backgrounds. From Australian and North American studies, it has been reported that by 2 or 3 years of age more than 30 of children with trisomy 21 are overweight, and by 9 years of age the average child with Down's syndrome is obese from the age of 10 years, the average weight of Dutch children with Down's syndrome is above the...

Reproductive System

Hormonal Complications Males Obese men have elevated levels of plasma estrone and estradiol that correlate with the degree of obesity. Plasma total testosterone and free testosterone (the biologically active moiety) are reduced in obese men, and the reductions correlate negatively with the degree of obesity. The reduced levels of free and total testosterone are not generally accompanied by hypogo-nadism or a decrease in libido, potency, or sperm count in obese men. Free and total plasma...

Breast feeding and Immunity to Infection

Human milk is the first form of nutrition for a neonate. Mammary glands are part of the integrated mucosal immune system and produce antibodies against mucosal pathogens that the mother is exposed to and which the infant is most likely to encounter. Breast milk contains several factors that protect against infections in the breast-fed infant either through passive immunity or by activating the infant's immune system. These include secretory IgA and IgM antibodies specific to maternal pathogenic...

Physiological Role Tissue Concentrations

The average human body contains between 200 and 400 mmol of manganese, which is fairly uniform in distribution throughout the body. There is relatively little variation among species with regard to tissue manganese concentrations. Manganese tends to be highest in tissues rich in mitochondria its concentration in mitochondria is higher than in cytoplasm or other cell organelles. Hair can accumulate high concentrations of manganese, and it has been suggested that hair manganese concentrations may...

Glycogen Storage Disorders

Glycogen is a complex carbohydrate stored primarily in the liver and muscle. Liver glycogen provides glucose to maintain blood-sugar levels between normal feeding defects of the liver enzymes for glycogen Figure 6 Glycogen storage disease type I. degradation lead to hypoglycemia and or liver disease because of excessive accumulation of glycogen. Muscle glycogen is an important substrate for energy production for normal muscle function, so disorders are usually indicated by cramping with...

Effects of Dietary Fats and Cholesterol on Lipoprotein Metabolism

The cholesterolemic effects of dietary fatty acids have been extensively studied. The saturated fatty acids Ci2 o, C14 0, and C16 0 have a hypercholester-olemic effect, whereas Cig 0 has been shown to have a neutral effect. Monounsaturated and polyunsatu-rated fatty acids in their most common cis configuration are hypocholesterolemic in comparison with saturated fatty acids. The effects of trans fatty acids on lipid levels are under active investigation. Our current knowledge shows that their...

Effects of Diet on Chylomicron Metabolism

Diets very high in saturated fat have been associated with increased postprandial chylomicrons and chy-lomicron remnants compared with diets rich in n-6 polyunsaturated fats however, human experiments carried out using moderate to high fat intake have not shown significant effects of different types of dietary fat or dietary cholesterol on postprandial lipoproteins. The effects of dietary carbohydrates on postprandial lipoproteins have also been studied. Most protocols have used diets very high...

Effects of Diet on LDL Metabolism

The effects of dietary fat and cholesterol on LDL metabolism have been extensively studied. However, the effects of dietary cholesterol are still highly controversial. Whereas some studies have demonstrated increased LDL production and decreased catabolism associated with high cholesterol intakes, others have failed to find such associations. Replacement of saturated by polyunsaturated fats has been associated with decreased LDL apo B production in some studies, whereas in other studies,...

Familial Combined Hyperlipidemia

Familial combined hyperlipidemia (FCH) was initially described as the combination of hypercholester-olemia and hypertriglyceridemia within the same kindred, and with kindred members having one of these abnormalities or both. Moreover, most subjects with FCH have HDL cholesterol levels below the 10th percentile. Affected subjects have elevation in VLDL, LDL, or both. This disorder has a frequency of approximately 10 in survivors of premature myocardial infarction (less than 60 years of age) and...

Familial Hypoalphalipoproteinemia

Severe HDL deficiency, characterized by HDL cholesterol levels < 10mgdl-1 is rare and may be due to Tangier disease, apo A-I deficiencies, LCAT deficiency, or fish-eye disease. The apo A-1 deficiency states are due to rare deletions, rearrangements, or point mutations within the apo A-I C-III A-IV gene complex. Familial hypoalphalipoproteinemia is relatively common and is characterized by HDL cholesterol levels below the 10th percentile of normal. These subjects have been reported to have...

Familial Lipoprotein a Excess

Lipoprotein (a) (Lp(a)) is an LDL particle with one molecule of apolipoprotein (a) attached to it. Elevated levels of Lp(a) (> 35-40 mgdl-1 or 90th percentile) have been associated with premature CHD. This increased risk appears to result from two different mechanisms cholesterol deposition in the arterial wall and inhibition of fibrinolysis. Lp(a) concentrations are highly variable among individuals however, they tend to remain constant during a person's lifetime. Between 80 and 90 of the...

The Postprandial Syndrome

Typically, the patient is a normal-weight woman of 20-50 years whose main complaint is of vague feelings of distress occurring predominantly mid morning, about 11.00 a.m.-12.00 noon, but occasionally mid afternoon or evening and never before breakfast. In between attacks, characterized by feeling of faintness, anxiety, nervousness, irritability, inner trembling, rapid heart beat, headache, and sweatiness, either alone or in combination, they may be completely well. More often they describe...

Artificial Nutrition Support Home Parenteral Nutrition and Home Enteral Tube Feeding

Patients suffering from chronic conditions often prefer to be treated in the familiar surroundings of their home rather than in hospital. When the treatment involves sophisticated techniques, it is essential that either the patient or the caregiver is adequately trained to distinguish between problems that can be easily remedied at home and those that need expert advice and treatment in hospital. With the increasing pressure for hospital beds and the increasing cost of hospital care, many forms...

The Feeding Fasting Cycle Energy Requirements

Energy is essential for many important body functions, including the maintenance of cellular integrity and function, new tissue synthesis, thermoregulation, and Table 1 Metabolic features and laboratory parameters of starvation and fasting Uncomplicated protein energy malnutrition (Marasmus) Hypoalbuminemic malnutrition (Kwashiorkor) expenditure Nitrogen loss Water, sodium Hormonal Albumin Transferrin Total lymphocyte Early small increase in catecholamines, glucagon, cortisol, growth hormone...

Food Borne Infections during Pregnancy

For many years it has been recognized that food-borne antenatal infections may cause death or serious fetal damage. Women may be more susceptible to the effects of infection during pregnancy because of immunological changes leading to suppression of the immune system (most commonly cell-mediated immunity), probably as a result of increases in pregnancy-associated sex steroids, such as oestradiol or progesterone. Among the most common causes of diarrhea during pregnancy are several food- or...

Summary Episodic and Tonic Factors in the Regulation of Appetite

Endogenous 5-HT and leptin represent two aspects of negative feedback integral to the appetite control Figure 3 The integration of peripherally generated episodic and tonic signals critical to the expression of appetite. Signals generated by both meal consumption and fat deposition are integrated into a complex hypothalamic system of neuropeptides, which in turn either stimulate or inhibit subsequent food intake. Abbreviations 5-HT, serotonin aMSH, alpha melanocortin stimulating hormone AgRP,...

Meal Timing

Does the timing of a meal in the day make a difference to any effects on behavior In other words, do any behavioral effects differ between breakfast, midday, and evening meals or between mid-morning and afternoon snacks Breakfast The potential effects of breakfast on performance and well-being continue to attract much interest, not least from industry, especially concerning the performance of schoolchildren. Pollitt and colleagues have argued that children are likely to be more susceptible than...

Effects of Alcohol on the Central Nervous System

Ethanol generally decreases the activity of the central nervous system. In relation to alcohol, the most important neurotransmitters in the brain are glutamate, gamma-aminobutyric acid (GABA), dopa-mine, and serotonin. Glutamate is the major excitatory neurotransmitter in the brain. Ethanol inhibits the N-methyl-d-aspartate (NMDA) subset of glutamate receptors. Ethanol thereby reduces the excitatory effects of glutamate. GABA is the major inhibitory neuro-transmitter in the brain. Alcohol...

Components of Metabolic Rate

Traditionally, the metabolic rate is divided into three components BMR, postprandial thermogenesis, and physical activity. The BMR usually comprises 50-60 of an individual's total energy expenditure and postprandial thermogenesis comprises 10 , which is used for the metabolic cost of processing (i.e., eating, absorbing, transporting, and storing food). The remaining energy is used for physical activity. The surge in oxygen uptake after a meal, known as postprandial thermogenesis, has been...

Safety and Toxicology

The acute oral LD50 (dose sufficient to kill one-half of the population of tested subjects) of caffeine is more than 200 mg kg-1 in rats, 230 mg kg-1 in hamsters and guinea pigs, 246mgkg-1 in rabbits, and 127mgkg-1 in mice. The sensitivity of rats to the lethal effects of caffeine increases with age, and higher toxicity is observed in male than in female rats. Vomiting, abdominal pain, photophobia, palpitations, muscle twitching, convulsions, miosis, and unconsciousness were described in...

Fish Lipids

In fish, depot fat is liquid at room temperature (oil) and is seldom visible to the consumer an exception is the belly flaps of salmon steaks. Many species of finfish and almost all shellfish contain less than 2.5 total fat, and less than 20 of the total calories come from fat. Almost all fish has less than 10 total fat, and even the fattiest fish, such as herring, mackerel, and salmon, contains no more than 20 fat (Table 1). In order to obtain a good general idea of the fat contents of most...

Aluminum Excretion and Body Retention

26Al studies have shown that most aluminum entering blood is excreted in the urine, with only approximately 1 lost in feces. In these studies, intersubject variability was conspicuous, such that 1 and 5 days after intake the range of fractional aluminum excretions was 0.5-0.8 and 0.6-0.9, respectively. In another study employing a single volunteer, the long-term retention of aluminum was determined. At early times this volunteer showed a retention pattern consistent with the mean of that found...

Clinical Significance of Postprandial and Fasting Hyperglycemia in Diabetic and Nondiabetic Populations

As with fasting blood glucose levels, postprandial hyperglycemia in nondiabetic populations is a predictor of insulin resistance and cardiovascular disease (CVD). The combined 20-year mortality data on men from the Whitehall, Paris prospective, and Helsinki policemen studies showed that the highest quintile compared with the lowest for the 2-h postplasma glucose load was associated with a 2.7 increased risk of CVD mortality. The fasting glucose values were less predictive for CVD, with only the...

Pregnancy and Glycemic Index

Throughout pregnancy in well-nourished urbanized women consuming typical Western diets, glucose tolerance deteriorates. During pregnancy, African women living in traditional rural populations and consuming high-carbohydrate low glycemic index diets do not invariably experience deterioration in their glucose tolerance. Clinical studies in the West show that women consuming similar high-carbohydrate low gly-cemic index diets throughout pregnancy also have no deterioration of glucose tolerance...

Food Uses of Aluminum Compounds

Aluminum compounds that may be employed as food additives are listed in Table 1. Although most are present in foods as trace components, others may be present in significant quantities. For example, aluminum-based baking powders, employing sodium aluminum phosfate (SALP), may contain more than 10mgg_1 of aluminum, and bread or cake made with these may contain 5-15 mg of the element per slice. American processed cheese may contain as much as 50 mg of aluminum per slice due to the addition of...

Pathophysiology of Preeclampsia

Pre-eclampsia is a syndrome with both fetal and maternal manifestations. The maternal disease is characterized by vasospasm, activation of the coagulation system, and perturbations in many humoral and autacoid systems related to volume and blood pressure control. The pathologic changes in this disorder are primarily ischemic in nature and affect placenta, kidney, liver, and brain. Of importance, and distinguishing pre-eclampsia from chronic or gestational hypertension, is that pre-eclampsia is...

Inborn Errors of Fructose Metabolism

Several genetically based abnormalities in fructose metabolism have been described in humans. Fructo-kinase deficiency leads to high levels of fructose in the blood and urine. In the absence of fructokinase, fructose can be metabolized to fructose-6-phosphate by hexokinase (EC 2.7.1.1), although at a low rate. Consequently, no serious health problems are associated with this abnormality. The aldolase A, B, and C enzymes catalyze the reversible conversion of fructose-1-diphosphate into...

Treating Different Types of Dehydration

In the majority of simple, nonsevere dehydration cases, plain water is an adequate rehydration solution. However, there are instances (e.g., children younger than 5 years of age dehydrated by vomiting and diarrhea) when water containing sodium and potassium is the proper hydrating agent. The most effective way of preventing and treating mild to moderate dehydration in infants and children with acute diarrhea is the oral administration of oral rehydration solutions (ORSs). There are a number of...

Causes of Mg Deficit

Complex relations exist between Mg and carbohydrate metabolism. Diabetes is frequently associated with Mg deficit and insulin may play an important role in the regulation of intracellular Mg content by stimulating cellular Mg uptake. Hypomagnesemia is the most common ionic abnormality in alcoholism because of poor nutritional status and Mg malabsorption, alcoholic ketoacidosis, hypophosphatemia, and hyperaldosteronism secondary to liver disease. Stress can contribute to Mg deficit by...

Definition

It is now accepted that some people exhibit, in the course of their everyday life, symptoms similar to those caused by acute neuroglycopenia and may, if accompanied by a capillary or arterialized venous blood glucose concentration of 2.8-2.5 mmoll-1 or less, justify description as being of postprandial reactive hypoglycemic origin. Reactive hypoglyce-mia may itself be a consequence of any one of a large number of well-recognized but generally uncommon conditions that can also produce...

Iodine Deficiency

Iodine deficiency is the most common cause of preventable mental retardation in the world. This fact, along with the recognition that iodine deficiency is not limited to remote rural populations, has stimulated agencies and governments to mobilize resources to eliminate this problem. This global effort, focusing primarily on iodization of salt for human and animal consumption, is slowly succeeding in eliminating a hidden set of disorders that have plagued mankind for centuries. Unlike many...

Conclusion

The measurement of body composition allows for the estimation of body tissues, organs, and their distributions in living persons without inflicting harm. It is important to recognize that there is no single measurement method in existence that allows for the measurement of all tissues and organs and no method is error free. Furthermore, bias can be introduced if a measurement method makes assumptions related to body composition proportions and characteristics that are inaccurate across...

Inadequate Dietary Intake of Zinc

In general, the risk of inadequate intake of dietary zinc within a population may be associated with the nature of the food supply, and its content and relative bioavailability of zinc. Animal source foods, in particular shellfish, small whole fish, beef, and organ meats such as liver and kidney, are rich sources of zinc. Furthermore, the zinc contained in animal source foods is more highly bioavailable than from plant source foods the presence of certain amino acids (e.g., histidine,...

Anemia

It has many causes but nutritional deficiencies, i.e., inadequate nutrient intakes and anemia secondary to disease processes, explain much childhood anemia. Acceptable hemoglobin levels in children are lower on average than in adults. The World Health Organization (WHO) accepted lower limit of normal hemoglobin is 110gl-1 for children 1-6 years old and 120gl-1 for those over 6 years. Infants are born with relatively high hemoglobin levels which, whilst...

Nutritional Management of Disorders

D M Klurfeld, US Department of Agriculture, Beltville, MD, USA 2005 Elsevier Ltd. All rights reserved. The primary functions of the colon are to absorb water and to form and store feces for excretion. The length of the large intestine in an adult is approximately 1.5 m several divisions and landmarks of the colon are shown in Figure 1. Disturbances in colonic function are symptoms of diseases or disorders, including constipation, diarrhea, diverticular disease, irritable bowel syndrome, and...

Probiotics and Prebiotics

Probiotics are live microbes that exert health benefits when ingested in sufficient quantities. Species of lactobacilli and bifidobacteria, sometimes combined with Streptococcus thermophilus, are the main bacteria used as probiotics in fermented dairy products. Most probiotic research has been done with nutra-ceutical preparations, but yogurt has been shown to alleviate lactose intolerance, prevent vaginal can-didosis in women with recurrent vaginitis, and reduce the incidence or severity of...

Key Nutrients Involved in Host Resistance to Infection

Ascorbic acid (vitamin C) Ascorbic acid is rapidly mobilized and utilized in infection and high levels of ascorbic acid are found in leucocytes. Studies in humans and animals have found a reduced T-cell response, delayed cutaneous hypersensitivity, and reduced epithelial integrity in vitamin C deficiency. Vitamin C supplementation is associated with increased lymphocyte proliferation in response to mitogen, increased phagocytosis by neutrophils, and decreased serum lipid peroxides. A role for...

Emerging Issues in the Twenty First Century

Some of the main emerging and reemerging nutrition issues of the new millennium for developing countries are those that reflect changing economic, demographic, and disease patterns and include HIV AIDS, the nutrition transition, refugees, adolescents, and aging. In developed countries, aging is also one of the main emerging issues, along with the continued increase in obesity in both adults and children, with concomitant increases in related diseases such as diabetes. It has been recognised...

Zinc and Other Minerals

Zinc is a component of many metalloenzymes including those needed for growth, pancreatic enzymes, and intestinal secretions. Although it is unusual to find a documented case of clinical zinc deficiency apart from occasional cases of acroder-matitis enteropathica, there has been recent concern over the possibility of relative zinc deficiency, especially among chronically ill patients with excessive intestinal secretions. Zinc deficiency could lead to impaired taste (hypogeusia) and appetite and...

What Is a Dietary Supplement How Are They Regulated in Different Countries

Each country has developed regulatory definitions and systems that place dietary supplements, particularly botanicals, into categories of drugs, traditional medicines, or foods. However, in the late 1980s, many countries launched major changes in regulations that may or may not have been approved at the time of this writing. Many regulations are still in draft form. The US Congress defined the term 'dietary supplement' in the Dietary Supplement Health and Education Act (DSHEA) of 1994. A...

Dietary Data Collection Methods

Food supply data Food supply data provide information on the type and amount of food available for human consumption to the country as a whole. The most common method of measuring this available food is through the use of food balance sheets. It is a method of indirectly estimating the amounts of food consumed by a country's population at a certain time. It provides data on food disappearance rather than on actual food consumption. It is calculated by using beginning and ending inventories, and...

Urolithiasis Kidney Stones

Although modest overindulgence in purine-rich food by normal subjects does not precipitate gout, it can predispose to uric acid lithiasis. Uric acid stones are relatively common in countries where the consumption of nucleic acid-rich beverages and food is high and in hot climates if insufficient fluids are consumed. Health foods such as yeast tablets, Spirulina, or supplements containing nucleotides also contribute to uric acid lithiasis. A number of compounds, such as vitamin C, increase uric...

Liver in Specific Hepatobiliary Disorders Hepatocellular Diseases

Alcoholic liver disease The term 'alcoholic liver disease' refers to a spectrum of types of hepatic injury associated with continuous alcohol ingestion, ranging from alcoholic fatty liver to alcoholic stea-tohepatitis, fibrosis, and cirrhosis. Nutritional disturbances in alcoholics are an important cause of morbidity and mortality all classes of nutrients are affected. Anorexia leads to decreased food intake and subsequent protein-calorie malnutrition. Maldigestion and malabsorption can occur...