Nutrition and Metabolism Quiz

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Questions and Answers

Which factor does NOT influence Basal Metabolic Rate (BMR)?

Dieting

Heart rate (correct)

Age

Height

What is a characteristic of a positive nitrogen balance?

It is irrelevant during pregnancy.

It indicates muscle breakdown.

It is necessary for growth. (correct)

It leads to energy depletion.

What distinguishes starvation from a hypermetabolic state?

In starvation, muscle protein is a secondary energy source.

Both utilize fat as the primary energy source.

Starvation primarily uses muscle protein for energy.

Only starvation leads to permanent organ damage. (correct)

Excessive nutrient intake leads to which of the following?

Stored fat accumulation (C) Signup and view all the answers

Which method uses oxygen consumption to assess metabolic rate?

Indirect calorimetry (B) Signup and view all the answers

What is the primary energy source used during starvation?

Stored fats and muscle proteins (D) Signup and view all the answers

Which condition likely does NOT lead to a hypermetabolic state?

Regular exercise (A) Signup and view all the answers

What typically happens during prolonged starvation?

Permanent organ damage (B) Signup and view all the answers

What is the primary purpose of urinary urea nitrogen (UUN) in assessing nutritional status?

To calculate total nitrogen output (A) Signup and view all the answers

Which statement accurately reflects the correction factor used for estimating total urinary nitrogen (TUN) from UUN?

UUN is multiplied by 1.25 for non-urea nitrogen components (A) Signup and view all the answers

Which of the following proteins is primarily used to monitor the immediate response to nutritional supplementation?

Retinol-binding protein (RBP) (A) Signup and view all the answers

Which of the following is NOT associated with a hypermetabolic state?

Decreased heart rate (B) Signup and view all the answers

What is the primary role of carbohydrates in the diet?

Serving as the principal source of energy (D) Signup and view all the answers

What factor must be considered when interpreting results of plasma proteins in nutritional assessments?

Fluid volume changes and acute-phase responses (B) Signup and view all the answers

Which group requires the highest percentage of essential amino acids in their diet?

Infants (A) Signup and view all the answers

In assessing the nutritional status of hospitalized patients, which two methods are essential?

Antropometric measurement and laboratory measurement (C) Signup and view all the answers

What does a negative nitrogen balance indicate?

More nitrogen is lost than consumed (B) Signup and view all the answers

Which method is primarily used to measure nitrogen excretion?

Urine urea nitrogen measurement (A) Signup and view all the answers

What is the caloric energy yield of one gram of carbohydrate?

4 kcal (B) Signup and view all the answers

In which situations is protein restriction particularly crucial?

Acute liver failure and end-stage renal disease (B) Signup and view all the answers

Which of the following factors is essential for accurate nitrogen balance study?

Calculation of protein intake and measurement of nitrogen output (B) Signup and view all the answers

Which nutrient category includes substances that must be obtained through diet because they cannot be synthesized by the body?

Essentials (A) Signup and view all the answers

What percentage of the calories used by the body is typically represented by the Basal Metabolic Rate (BMR)?

60-70% (A) Signup and view all the answers

In which group of vitamins is Vitamin D considered essential only for certain populations?

Fat-soluble vitamins (B) Signup and view all the answers

What factors can influence the variation in the requirement of nutrients for individuals?

Age, sex, reproductive status, and health conditions (C) Signup and view all the answers

What is the definition of energy balance as per the provided information?

A state where energy intake equals energy expenditure plus storage changes (B) Signup and view all the answers

What major component of nutrition includes substances such as carbohydrates, proteins, and lipids?

Macronutrients (B) Signup and view all the answers

Which of the following is not considered an essential nutrient according to the information provided?

Saturated fatty acids (A) Signup and view all the answers

According to the WHO, what factors are considered when determining the level of energy intake that balances health?

Energy expenditure, body size, and body composition (B) Signup and view all the answers

What percentage of child deaths in developing countries can be attributed to undernutrition?

Approximately 50% (B) Signup and view all the answers

Which of the following issues can arise from micronutrient deficiencies?

Impaired immune function (B) Signup and view all the answers

What condition is defined by a BMI greater than or equal to 30?

Obesity (D) Signup and view all the answers

What is the primary advantage of enteral feeding over total parenteral nutrition (TPN)?

It prevents gut functioning issues (C) Signup and view all the answers

Which of the following is NOT a consequence of micronutrient deficiency?

Increased athletic performance (D) Signup and view all the answers

What does parenteral nutrition primarily aim to do?

Improve nutritional status (C) Signup and view all the answers

For an adult who weighs 70 kg and is 1.75 m tall, what is their BMI?

22.9 (B) Signup and view all the answers

Enteral feeding typically involves providing nutrients through what method?

Tube insertion into the stomach (B) Signup and view all the answers

Which statement accurately describes the implications of a negative nitrogen balance (NB)?

It suggests the individual is in a state of starvation or hypermetabolic disease. (D) Signup and view all the answers

What is the energy provided by one gram of lipids compared to one gram of protein?

4 kcal for protein, 9 kcal for lipids. (C) Signup and view all the answers

During which condition is protein-energy malnutrition (PEM) most likely to occur?

Lack of sufficient protein and calories. (B) Signup and view all the answers

What dietary condition describes the symptoms of severe protein deficiency in children?

Kwashiorkor affects infants switched to carbohydrate diets. (C) Signup and view all the answers

How do high-fiber diets affect the bioavailability of certain minerals?

They lower the bioavailability of divalent metals. (A) Signup and view all the answers

What percentage of calories from fat does the American Heart Association recommend should be reduced to less than?

30% (C) Signup and view all the answers

Which of the following best describes marasmus?

It results from severe deficiency in protein and calories. (B) Signup and view all the answers

Which macronutrient is considered the most energy-dense?

Lipids (B) Signup and view all the answers

Study Notes

Human Nutrition & Biochemical Parameters of Nutrition

The science of nutrition focuses on the qualitative and quantitative aspects of diet and the utilization of dietary components for maintaining health.
Major components for human nutrition include carbohydrates, proteins, lipids, minerals, trace elements, vitamins, and fiber. These are biochemically well-defined components.
Essential nutrients are those that the body cannot synthesize and must be obtained through diet, including essential amino acids and fatty acids, and specific vitamins (A, E, K, water-soluble vitamins). Vitamin D is essential for children, but not adults.

Essential Amino Acids

A list of essential and conditionally essential amino acids is included.
The table differentiates between nonessential, conditionally essential, and essential amino acids.

Essential Fatty Acids

Alpha-linolenic acid (ALA) and linoleic acid (LA) are essential fatty acids.

Energy Requirements

Energy intake should balance energy expenditure based on age, sex, reproductive status, disease, injury and therapeutic interventions, body size and composition.
Energy requirements (ER) for children and pregnant/lactating women include energy for tissue development and milk production.
Energy balance is when energy intake equals energy expenditure and changes in stored energy.

Basal Metabolic Rate (BMR)

BMR is the resting energy expenditure, about 60-70% of total calories burned.
BMR encompasses the energy used for basic bodily functions, including heart beat, cell proliferation, respiration, maintaining body temperature, circulation and nutrient processing.
BMR is affected by factors like age, weight, height, gender, environmental temperature, dieting, and exercise habits.
BMR can be measured via direct or indirect calorimetry.

Nitrogen Balance

Nitrogen balance assesses expenditure of endogenous energy.
A positive nitrogen balance (protein intake > protein loss) is crucial for growth (children and fetus), pregnancy, lactation and physiologically stressful situations.
Accurate assessment of nitrogen output needs a detailed diet record and measurement of fecal and urinary nitrogen (with correction factors).
Urine urea nitrogen (UUN) is used to estimate total urinary nitrogen (TUN). UUN constitutes 80-90% of the total nitrogen output.

Excessive Nutrients

Excessive nutrients are stored as fat and can lead to obesity.
If insufficient nutrients are available, stored fats and muscle proteins are used for energy (i.e. glucose).

Starvation

Starvation is a severe deficiency in caloric energy intake.
Prolonged starvation can cause permanent organ damage and death.
Starvation results from imbalance between energy intake and energy expenditure.

Starvation vs. Hypermetabolic Status

Starvation is due to extreme lack of nutrients.
Hypermetabolic status is an extreme metabolic response to injury or infection initiated by hormones and cytokines.
During starvation, fat and muscle are used for energy, while in hypermetabolic states muscle protein is the primary source of amino acids for gluconeogenesis.

Observations of Hypermetabolic States

Characteristics like fever and increased basal metabolic rate, nutritional needs, heart rate and cardiac output, negative nitrogen balance, increased hepatic gluconeogenesis, and synthesis of acute-phase proteins are associated.

Carbohydrates

Carbohydrates are the primary energy source, contributing 50-60% of total calories.
Excessive carbohydrate intake leads to weight gain.
Insufficient intake leads to mobilization of body fat and associated ketosis, electrolyte loss, and dehydration.

Protein Requirements

Dietary proteins provide amino acids for tissue protein synthesis.
Essential amino acids are not synthesized by the body and must be obtained in the diet.
The quality of dietary protein is determined by its essential amino acid content. Different life stages (infants, children, and adults) have different recommended essential amino acid proportions.

Good-Quality Protein

Good-quality protein is essential to replace losses during hypermetabolic states associated with specific conditions like fever, burns, fractures, surgical trauma.

Nitrogen Balance Studies

Nitrogen balance studies assess utilization of dietary amino acids for protein synthesis, and determine balance between anabolic/catabolic processes.
For accurate assessment, detailed diet records and measurement of fecal and urinary nitrogen (with corrective factors) are needed.

Urinary Urea Nitrogen

Urinary urea nitrogen (UUN) estimates total urinary nitrogen content.
UUN is often used for estimating total nitrogen as it constitutes 80 to 90% of the total nitrogen output.

Positive vs. Negative Nitrogen Balance

Positive nitrogen balance (protein intake > protein loss) is associated with health and required during growth, development, and pregnancy.
Negative nitrogen balance (protein intake < protein loss) during starvation, and certain disease states requires corrective nutritional support.

Lipids

Lipids are the most energy-dense macronutrients, providing 9 kcal per gram.
A typical American diet contains 35-45% of calories from fat.
The American Heart Association recommends reducing fat consumption to less than 30% of total caloric intake to maintain good health.

Minerals

A list of electrolytes, minerals, and trace minerals is included here.

Fiber

Fiber is composed of plant cell components indigestible by gut enzymes, but they greatly contribute to colonic health.
Specific insoluble fibers like cellulose and lignin are good for colonic function.
High fiber diets and fiber components (phytates) can decrease the bioavailability/absorption of minerals (like calcium, iron, and zinc).

Malnutrition

Malnutrition refers to deficiencies or excesses in nutrient intake, nutritional imbalance or impaired nutrient utilization.
It includes undernutrition (wasting, stunting, underweight, micronutrient deficiencies), overweight, obesity and diet-related non-communicable diseases.
Wasting is defined as low weight-for-height, often associated with recent weight loss.

Types of Malnutrition

Protein-energy malnutrition (PEM): is due to lack of sufficient protein and energy (calories).
Micronutrient deficiency: Caused by lack of specific vitamins and minerals.
Obesity: results from excessively consuming foods exceeding body needs.

Protein Malnutrition (Kwashiorkor)

Kwashiorkor is a severe protein deficiency.
It's prevalent in underdeveloped regions where breastfeeding infants are abruptly switched to high-carbohydrate diets.
Predominantly affects children younger than 5 years old.

Protein-Energy Malnutrition (Marasmus)

Marasmus is a severe overall nutritional deficiency in both calories and protein.
Signs of starvation, such as loss of subcutaneous fat and muscle mass, are characteristic.

Degrees of Protein-Energy Malnutrition

Protein-energy malnutrition degrees are classified based on Body Mass Index (BMI).

Undernutrition

Undernutrition occurs when individuals receive insufficient nutrients to meet their needs.
In developing countries, undernutrition is a major contributor to child mortality.

Micronutrient Deficiency

Micronutrient deficiencies arise from lacking one or more vitamins and/or minerals.
This can cause various health problems, including blindness, impaired immune function, increased infection severity, and decreased physical growth, intellectual potential and adult productivity.

Obesity

Obesity is characterized by a Body Mass Index (BMI) of 30 or greater.
Despite undernutrition remaining a major concern in developing countries, obesity is a growing problem across affluent societies globally.

BMI

BMI is a measure of a person's nutritional status.
Weight in kilograms is divided by the square of the person's height in meters (kg/m²).

Therapeutic Nutrition Support

PEM and undernourishment, and specific nutrient deficiencies necessitate appropriate nutritional intervention for treatment.

Enteral Feeding

Enteral feeding delivers nutrients directly into the stomach or intestine.
Commercial formulas tailored to specific needs are used for maintaining proper nutrition.
This method is generally preferred over total parenteral nutrition (TPN) when the gut is functional.

Parenteral Nutrition

Parenteral nutrition (PN) provides nutrients intravenously.
This approach is for patients unable to obtain necessary nutrients through normal oral or enteral routes.
Isotopic lipid emulsions, glucose, amino acids, electrolytes, and micronutrients are included in these solutions, often offering up to 2500 kcal in 3 liters.

Biochemical Parameters for Monitoring Nutritional Status

Assessing nutritional status of hospitalized patients (e.g., in hospitals or nursing homes) involves anthropometric measurements, physical examinations, and laboratory measurements (like those listed below).

Laboratory Tests for Monitoring PEM Response

A table provides various laboratory parameters, explaining their associated rationals and comments, like urine urea nitrogen, Total urine nitrogen, Plasma albumin, Plasma transthyretin (prealbumin), Plasma transferrin, Plasma retinol-binding protein, Plasma zinc, and Plasma triglycerides.

Interpretation of Protein Synthesis Results

Factors such as alteration in fluid volume and fluid shifts, presence of acute-phase response (like due to trauma, infection, or malignancy), etc., which affect albumin/protein values should be considered.
Lower levels of certain proteins including transthyretin, transferrin, and retinol-binding proteins, despite being useful for following response to treatments, should not be exclusively attributed to malnutrition.
Biological half-lives of specific proteins play a key role when monitoring responses to supplementation/treatment.

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Description

Test your knowledge on key concepts related to nutrition and metabolism, including Basal Metabolic Rate, nitrogen balance, and energy sources during starvation. This quiz covers factors influencing metabolic states and the roles of various nutrients in the diet.