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Biology of Eating and Digestion
Methods to Assess Energy Balance
Assessing Caloric Intake
Assessing Caloric Content of Foods
Assessing Energy Expenditure
Assessing Body Composition
Assessing Physical Activity
Biology of Obesity
Toxicity Related to Excess Caloric Intake/Obesity
Adaptation of Liver and Adipose Tissue to Excess Calories
Ectopic Fat Deposition
Metabolic Syndrome
Therapeutic Options for Managing Metabolic Syndrome
Nonalcoholic Steatohepatitis (NASH)
Alteration in Drug Pharmacokinetics and Metabolism in Obesity and NAFLD
Endocrine Dysfunction in Obesity, Metabolic Syndrome, and NAFLD
Obesity and Cancer Risk
Health Benefits and Life Extension Associated with Caloric Restriction
Treatment of Obesity
Economic, Sociological, and Legal Aspects of the Obesity Epidemic
Health Insurance and Obesity
Changing the Environment: Family and Community Approaches to Healthy Eating and Physical Activity
Food Labels
Governmental and Corporate Issues
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Biology of Eating and Digestion
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All biotic organisms derive energy from food to sustain life and this energy “drives” various cellular functions, including digestion, metabolism, pumping blood, and muscle contractions. Nutrients can broadly be defined as chemical substances found in food that are necessary for proper growth and development, reproduction, and repair following injury. Based on their chemical nature, nutrients can be grouped into organic (carbon-containing) and inorganic classifications. Carbohydrates, proteins, fats, and vitamins comprise the former, while minerals and water are inorganic nutrients essential for life (Stipanuk, 2006). Inorganic nutrients such as minerals can be absorbed into the body through food and are generally incorporated into the food chain through environmental sources (soil, water). Minerals comprise ~4% of the body weight in humans and in combination with water furnish a major part of the obligatory milieu necessary for cellular functioning (pH, osmolarity). Macrominerals are those whose abundance is generally 0.01% of body weight or daily required amounts exceed 100 mg per day. Calcium, phosphorous, sodium, and magnesium fall in this group. Other minerals that are not as abundant can be equally important for an organism. Trace minerals are defined as minerals whose concentration is <0.01% of total body weight. Other alternative definitions include nutrients whose requirements are below 1 ppm. Iron, zinc, copper, iodine, selenium, and molybdenum are six essential trace elements with established recommended dietary allowances. Overall, trace nutrients perform a variety of important functions, including transport of oxygen (iron as a part of hemoglobin), catalysis of biological reactions as component of enzymes (iron, zinc), and as part of other organic molecules (selenocysteine). While inorganic compounds serve important roles in physiology, the energy in food is derived from metabolism of organic substances. Organic compounds are generally synthesized by living cells from simpler molecules. For example, green plants and marine phytoplankton utilize photosynthesis to convert the very simple ...