p.10
Fasting and Fuel Utilization
What determines how long a person can survive without food?
The amount of fat stored in adipose tissue.
p.9
Fasting and Fuel Utilization
What happens to adipose tissue as glucagon levels rise during fasting?
Adipose tissue breaks down triacylglycerol stores into fatty acids and glycerol, which are released into the blood.
p.2
Metabolic Fuels: Carbohydrates, Fats, and Proteins
What are the primary functions of the diet besides providing energy?
To produce precursors for structural components and supply essential compounds that the body cannot synthesize.
p.9
Fasting and Fuel Utilization
What happens to muscle protein during fasting?
Muscle protein is degraded, producing amino acids that are released into the blood, mainly as alanine and glutamine.
p.10
Nutritional Counseling and Clinical Applications
What are the two diseases associated with malnutrition and starvation?
Kwashiorkor and marasmus.
p.2
Fasting and Fuel Utilization
What is the function of liver glycogen during fasting?
To maintain blood glucose levels.
p.9
Fasting and Fuel Utilization
How does muscle utilize fatty acids and ketone bodies during fasting?
Muscle oxidizes fatty acids released from adipose tissue and ketone bodies produced by the liver.
p.7
Fuel Metabolism and Nutrition: Basic Principles
What is the primary energy source for the brain?
The brain depends on glucose, which it oxidizes to produce ATP.
p.10
Nutritional Counseling and Clinical Applications
What characterizes kwashiorkor?
Adequate calories but low protein in the diet.
p.10
Nutritional Counseling and Clinical Applications
What happens to protein synthesis in kwashiorkor?
It decreases due to dietary protein deficiency.
p.3
Dietary Recommendations for Macronutrients and Micronutrients
What dietary changes are recommended for obesity treatment?
Treatment involves decreasing food intake and increasing exercise.
p.2
Energy Expenditure and Basal Metabolic Rate (BMR)
What is Diet-induced thermogenesis (DIT)?
The elevation in metabolic rate during digestion and absorption of foods.
p.3
Dietary Recommendations for Macronutrients and Micronutrients
What is the recommended percentage of total calories from fat?
Fat should constitute between 20% and 35% of total calories.
p.6
Digestion and Absorption of Nutrients
How are triacylglycerols digested in the intestine?
They are emulsified by bile salts and digested by pancreatic lipase into 2-monoacylglycerols and fatty acids.
p.3
Body Mass Index (BMI) and Health Implications
What is the formula for calculating Body Mass Index (BMI)?
BMI is calculated by dividing weight in kilograms by height in meters squared (BMI = kg/m²).
p.10
Nutritional Counseling and Clinical Applications
What are common symptoms of kwashiorkor?
Hepatomegaly and a distended abdomen.
p.3
Body Mass Index (BMI) and Health Implications
What health issues are associated with obesity?
Obesity is linked to hypertension, cardiovascular disease, and type 2 diabetes mellitus.
p.5
Digestion and Absorption of Nutrients
What are the digestive products of dietary fats?
Fatty acids and 2-monoacylglycerols.
p.8
Nutritional Counseling and Clinical Applications
What is the significance of intravenous feeding solutions containing glucose?
They provide glucose but lack essential fatty and amino acids and are suitable only for brief periods.
p.6
Digestion and Absorption of Nutrients
How are proteins initially digested?
By pepsin in the stomach and then by pancreatic enzymes in the intestine.
p.10
Nutritional Counseling and Clinical Applications
What causes the bloating seen in kwashiorkor?
Lack of albumin leading to osmotic pressure differences.
p.9
Prolonged Fasting and Starvation Adaptations
What metabolic changes occur in the body after 3 to 5 days of starvation?
Muscle decreases its use of ketone bodies, blood ketone body levels rise, and the brain begins to oxidize ketone bodies for energy.
p.9
Prolonged Fasting and Starvation Adaptations
What happens to gluconeogenesis in the liver during prolonged fasting?
Liver gluconeogenesis decreases, sparing muscle protein.
p.3
Dietary Recommendations for Macronutrients and Micronutrients
What is the maximum recommended cholesterol intake for healthy individuals?
Cholesterol intake should be no more than 300 mg/day.
p.4
Nutritional Counseling and Clinical Applications
What is nitrogen balance?
The state where degradation of body protein equals synthesis of new protein.
p.3
Energy Expenditure and Basal Metabolic Rate (BMR)
What are common symptoms of hypothyroidism?
Symptoms include lethargy, dry skin, husky voice, decreased memory, and weight gain.
p.1
Overview of Fuel Metabolism
What are the major fuels of the body?
Carbohydrates, fats, and proteins.
p.2
Energy Expenditure and Basal Metabolic Rate (BMR)
What is the estimated Basal Metabolic Rate (BMR) calculation?
BMR = 24 kcal/kg body weight per day.
p.8
Metabolic Fuels: Carbohydrates, Fats, and Proteins
Which tissues particularly require glucose?
The brain and red blood cells.
p.1
Hormonal Regulation: Insulin and Glucagon
How does insulin affect fuel storage?
Insulin increases in the fed state and promotes the storage of fuel.
p.9
Prolonged Fasting and Starvation Adaptations
What is the effect of prolonged fasting on urea production?
Less urea is produced from amino acid nitrogen in starvation than after an overnight fast.
p.8
Fasting and Fuel Utilization
What happens to liver glycogen stores after 4 to 6 hours of fasting?
They are depleted, leading to gluconeogenesis as the major process for maintaining blood glucose levels.
p.1
Energy Expenditure and Basal Metabolic Rate (BMR)
What is the daily energy expenditure (DEE) composed of?
The energy required for the basal metabolic rate (BMR) and the energy required for physical activity.
p.6
Nutritional Counseling and Clinical Applications
What is the effect of untreated Type 1 Diabetes Mellitus on metabolism?
It leads to low insulin levels, causing muscle protein and adipose triacylglycerol degradation, resulting in severe weight loss and metabolic derangements.
p.9
Fasting and Fuel Utilization
How does the liver produce ketone bodies?
The liver converts fatty acids to acetyl CoA through β-oxidation, which is then used to synthesize ketone bodies like acetoacetate and α-hydroxybutyrate.
p.2
Energy Expenditure and Basal Metabolic Rate (BMR)
What is the role of ATP generated by fuel metabolism?
It is used for biochemical reactions, muscle contraction, and other energy-requiring processes.
p.7
Fuel Metabolism and Nutrition: Basic Principles
What are the two main fates of glucose in the liver during the fed state?
Glucose is either oxidized to CO2 and H2O for energy or converted to glycogen and triacylglycerols.
p.9
Prolonged Fasting and Starvation Adaptations
How does the brain's fuel utilization change during prolonged fasting?
The brain decreases its use of glucose and starts to oxidize ketone bodies for energy.
p.8
Metabolic Fuels: Carbohydrates, Fats, and Proteins
What are the carbon sources for gluconeogenesis?
Lactate, glycerol, amino acids (particularly alanine), and propionate.
p.7
Fuel Metabolism and Nutrition: Basic Principles
What is the role of amino acids in the fed state?
Amino acids are used for protein synthesis, nitrogenous compounds, and can be oxidized for ATP.
p.7
Fasting and Fuel Utilization
What hormonal changes occur during fasting?
Insulin levels decrease and glucagon levels increase, stimulating the release of stored fuels.
p.5
Fuel Metabolism and Nutrition: Basic Principles
What can amino acids be used for in the body?
To synthesize proteins, produce nitrogen-containing compounds, or oxidized for energy.
p.6
Hormonal Regulation: Insulin and Glucagon
How do hormone levels change after digestion?
Insulin levels rise due to increased blood glucose and amino acids, while glucagon levels fall in response to glucose.
p.5
Digestion and Absorption of Nutrients
What are the main products of dietary carbohydrate digestion?
Monosaccharides, mainly glucose.
p.5
Fuel Metabolism and Nutrition: Basic Principles
How is glucose utilized in the body after absorption?
It is oxidized for energy or stored as glycogen in the liver and muscle.
p.7
Fuel Metabolism and Nutrition: Basic Principles
How do muscle cells utilize glucose?
Muscle cells take up glucose stimulated by insulin, oxidizing it for ATP and storing it as glycogen.
p.1
Metabolic Fuels: Carbohydrates, Fats, and Proteins
What happens to excess fuel consumed?
It is stored mainly as fat and also as glycogen.
p.5
Metabolic Fuels: Carbohydrates, Fats, and Proteins
What is the major dietary carbohydrate?
Starch, the storage form of carbohydrate in plants.
p.2
Metabolic Fuels: Carbohydrates, Fats, and Proteins
What is the major fuel store of the body?
Adipose triacylglycerol (triglyceride).
p.9
Fasting and Fuel Utilization
What is the fate of glycerol released from adipose tissue during fasting?
Glycerol is converted to glucose by the liver.
p.3
Body Mass Index (BMI) and Health Implications
What characterizes anorexia nervosa?
Anorexia nervosa is characterized by self-induced weight loss and an obsession with being thin.
p.2
Energy Expenditure and Basal Metabolic Rate (BMR)
How does physical activity affect daily energy expenditure (DEE)?
It can add significantly to DEE, varying from about 30% to over 50% of BMR depending on activity level.
p.7
Fuel Metabolism and Nutrition: Basic Principles
How does the liver use excess glucose?
Excess glucose is stored as glycogen for fasting periods or converted to fatty acids and triacylglycerols.
p.6
Digestion and Absorption of Nutrients
What happens to triacylglycerols after digestion?
They are packaged into chylomicrons, which enter the lymph and then the blood.
p.4
Dietary Recommendations for Macronutrients and Micronutrients
What are the two essential fatty acids mentioned that can be found in high levels in fish oils?
Arachidonic acid and eicosapentaenoic acid (EPA).
p.6
Nutritional Counseling and Clinical Applications
What is cystic fibrosis and its impact on digestion?
A genetic disease affecting chloride ion channels, leading to partial digestion of fats and proteins and resulting in nutritional deficiencies.
p.7
Fasting and Fuel Utilization
What is hyperlipidemia?
Hyperlipidemia refers to elevated blood lipid levels, with normal triglycerides being less than 150 mg/dL.
p.4
Nutritional Counseling and Clinical Applications
What occurs during a negative nitrogen balance?
Degradation of body protein exceeds synthesis, leading to more nitrogen excreted than ingested.
p.10
Nutritional Counseling and Clinical Applications
What is marasmus?
A condition resulting from a diet deficient in both protein and calories.
p.1
Fasting and Fuel Utilization
What fuels are used during fasting?
Stored fuels are used to derive the energy needed to survive until the next meal.
p.1
Hormonal Regulation: Insulin and Glucagon
What role does glucagon play during fasting?
Glucagon increases in the fasting state and promotes the release of stored fuel.
p.1
Nutritional Counseling and Clinical Applications
What is the significance of understanding basic fuel metabolism?
It is critical for understanding normal human functioning and diagnosing various disorders.
p.4
Nutritional Counseling and Clinical Applications
What are essential amino acids?
Nine amino acids that cannot be synthesized in the body and must be obtained from the diet.
p.3
Body Mass Index (BMI) and Health Implications
What are the BMI classifications for underweight and normal range?
Underweight is defined as a BMI less than 18.50, and normal range is between 18.50 and 24.99.
p.1
Metabolic Fuels: Carbohydrates, Fats, and Proteins
What happens to ingested fuel in the fed state?
It is used to meet immediate energy needs and excess fuel is stored as glycogen or triacylglycerol.
p.8
Metabolic Fuels: Carbohydrates, Fats, and Proteins
What is the primary role of the liver in glucose production?
Maintaining blood glucose levels.
p.1
Prolonged Fasting and Starvation Adaptations
What changes occur in prolonged fasting?
Changes in the use of fuel stores permit survival for extended periods.
p.6
Digestion and Absorption of Nutrients
What are the two main disaccharides ingested and their enzymes?
Sucrose and lactose; sucrase converts sucrose to fructose and glucose, while lactase converts lactose to glucose and galactose.
p.8
Metabolic Fuels: Carbohydrates, Fats, and Proteins
What is the metabolic fate of glucose in the brain?
It is oxidized to CO2 and H2O.
p.7
Fasting and Fuel Utilization
What is hypoglycemia?
Hypoglycemia refers to low blood glucose levels, typically below 80 mg/dL.
p.6
Digestion and Absorption of Nutrients
Where do glucose and amino acids travel after leaving the intestinal epithelial cells?
Through the hepatic portal vein to the liver.
p.4
Dietary Recommendations for Macronutrients and Micronutrients
What role do vitamins and minerals play in the diet?
They serve as cofactors for enzymes.
p.3
Energy Expenditure and Basal Metabolic Rate (BMR)
What is Graves disease and how does it affect BMR?
Graves disease is a form of hyperthyroidism characterized by elevated BMR and excess thyroid hormone production.
p.5
Fuel Metabolism and Nutrition: Basic Principles
What happens to glucose in the liver besides being stored as glycogen?
It is converted to triacylglycerols and released into the blood as VLDL.
p.7
Fasting and Fuel Utilization
What does the liver do during fasting?
The liver produces glucose and ketone bodies, maintaining blood glucose levels through glycogenolysis and gluconeogenesis.
p.5
Digestion and Absorption of Nutrients
How are dietary fats transported in the body after digestion?
They are packaged in chylomicrons and secreted into the lymph and blood.
p.4
Nutritional Counseling and Clinical Applications
What can result from high-protein diets that are very low in calories and low in biologic value?
Negative nitrogen balance.
p.7
Fuel Metabolism and Nutrition: Basic Principles
What happens to triacylglycerols from chylomicrons and VLDL in the fed state?
They are digested by lipoprotein lipase into fatty acids and glycerol.
p.5
Digestion and Absorption of Nutrients
What is the fate of dietary cholesterol after absorption?
It follows the same fate as dietary triacylglycerols.
p.4
Dietary Recommendations for Macronutrients and Micronutrients
What distinguishes high-quality protein from low-quality protein?
High-quality protein contains many essential amino acids, while low-quality protein lacks some essential amino acids.
p.4
Dietary Recommendations for Macronutrients and Micronutrients
Which minerals are required in large amounts and what is their function?
Calcium and phosphate, which serve as structural components of bone.
p.6
Digestion and Absorption of Nutrients
What is the result of protein digestion?
Proteins are degraded to a mixture of amino acids, which enter intestinal epithelial cells and some are metabolized.
p.5
Digestion and Absorption of Nutrients
Which enzymes are involved in the digestion of starch?
Salivary α-amylase and pancreatic α-amylase.
p.5
Digestion and Absorption of Nutrients
What completes the conversion of starch to glucose?
Enzymes with maltase and isomaltase activity on the brush border of intestinal epithelial cells.
