Biochem - Principles of Nutrition

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Questions and Answers

Which of the following factors is NOT included in the composition of a healthy diet?

High-fat dairy products (correct)

Whole grains

Fruits and vegetables

Lean meats and poultry

Which term best describes the total amount of calories burned in a day considering basal metabolic rate and physical activity?

Basal Caloric Needs

Caloric Deficit

Daily Energy Expenditure (correct)

Active Metabolic Rate

Which of the following statements about Basal Metabolic Rate (BMR) is correct?

BMR is constant regardless of age or sex.

BMR accounts for the energy expended while at rest. (correct)

BMR increases with weight loss.

BMR is higher in individuals with lower muscle mass.

What does Diet-Induced Thermogenesis (DIT) refer to?

Energy used in digestion and absorption of nutrients Signup and view all the answers

Which dietary guideline emphasizes the consumption of foods low in saturated fats and added sugars?

Eatwell Guide Signup and view all the answers

Which factor is most likely to contribute to nutritional deficiencies and malnutrition?

Lack of variety in food choices Signup and view all the answers

What is the primary purpose of Total Parenteral Nutrition (TPN)?

To supply nutrients intravenously to those unable to eat Signup and view all the answers

Which dietary assessment tool focuses on the recommended intake levels of key nutrients?

Dietary Reference Intakes Signup and view all the answers

What is the primary source of energy for the body?

Carbohydrates Signup and view all the answers

What is the Recommended Dietary Allowance (RDA) of potassium for a healthy adult?

4700 mg Signup and view all the answers

Which food group is emphasized in a healthy diet for nutrient density?

Fruits and vegetables Signup and view all the answers

Which macro-nutrient provides the highest energy yield per gram?

Fat Signup and view all the answers

Which of the following elements has an unknown approximate body content in a healthy adult?

Molybdenum Signup and view all the answers

What is the primary function of the Basal Metabolic Rate (BMR)?

Measures energy consumption while at rest Signup and view all the answers

What is the effect of cold exposure on metabolic thermogenesis?

Increases energy expenditure Signup and view all the answers

For which demographic would BMR generally be expected to be lower?

Individuals in starvation Signup and view all the answers

What is the total daily energy expenditure (TDEE) a function of?

BMR, physical activity, and DIT Signup and view all the answers

Which vitamin is directly associated with energy metabolism?

Vitamin B complex Signup and view all the answers

What is the caloric value of alcohol per gram?

7 kcal Signup and view all the answers

Which mineral has the same RDA for both males and females?

Selenium Signup and view all the answers

Which principle of nutrition emphasizes consuming food in appropriate amounts to avoid health issues?

Moderation Signup and view all the answers

What is the primary role of macronutrients in the diet?

Provide energy and essential nutrients Signup and view all the answers

What does the Basal Metabolic Rate (NEAT) primarily indicate?

Calories burned by the body performing basic functions Signup and view all the answers

Which of the following substances is not classified as a water-soluble vitamin?

Vitamin A Signup and view all the answers

Which dietary reference intake is sufficient for a very small percentage of the population with low needs?

Lower Reference Nutrient Intake (LRNI) Signup and view all the answers

What is the main component not included in Total Parenteral Nutrition (TPN)?

Fibers Signup and view all the answers

What is the main type of lipids that provide the highest energy yield when oxidized?

Triglycerides Signup and view all the answers

Which BMI range indicates a normal weight classification for adults?

18.5 - 24.9 kg/m2 Signup and view all the answers

Which nutrient classification is critical for optimal growth and development in children?

Lipids Signup and view all the answers

What would be the BMI for an individual weighing 80 kg and measuring 1.75 meters tall?

26.1 kg/m2 Signup and view all the answers

How do macrominerals differ from other minerals?

Required in quantities greater than 100mg/day Signup and view all the answers

Which macronutrient is considered a source of amino acids?

Protein Signup and view all the answers

Which of the following best describes the Recommended Dietary Allowance (RDA)?

It meets the nutrient needs of roughly 97% of a healthy population. Signup and view all the answers

What is the primary purpose of an Estimated Average Requirement (EAR)?

To estimate the average nutrient needs of a group. Signup and view all the answers

What characterizes micronutrients in a diet?

Required in small amounts Signup and view all the answers

What is a significant risk of exceeding the Upper Limit (UL) for nutrient intake?

Increased likelihood of adverse effects. Signup and view all the answers

Which of the following is a major energy-yielding nutrient?

Carbohydrates Signup and view all the answers

How is Body Mass Index (BMI) calculated?

Body weight in kilograms divided by height in meters squared. Signup and view all the answers

Which practice contributes significantly to maintaining a healthy weight?

Being physically active for 30-60 minutes a day Signup and view all the answers

Which component is crucial for assessing nutrient intake in dietary planning for populations?

Dietary Reference Intakes (DRI) Signup and view all the answers

Which principle of nutrition emphasizes not relying on one type of food for all nutrients?

Balance Signup and view all the answers

What is the Recommended Dietary Allowance (RDA) for iron in adult females?

18mg Signup and view all the answers

Which of the following micro-minerals has its RDA listed as 150mcg for adults?

Iodine Signup and view all the answers

For a male to maintain his basic metabolic rate (BMR), how many calories does he require per day?

1,800 kcal/day Signup and view all the answers

Which dietary principle involves including a variety of different foods in your diet?

Variety Signup and view all the answers

How many calories per day is the RDA for females when accounting for pregnancy?

2,800 kcal/day Signup and view all the answers

Which mineral's approximate body content in healthy adults is listed as unknown?

Molybdenum Signup and view all the answers

For energy control, what does moderation in dietary intake refer to?

Avoiding too much or too little of anything Signup and view all the answers

What does the Lower Reference Nutrient Intake (LRNI) represent?

Minimum intake for a small percentage of the population Signup and view all the answers

The Estimated Average Requirement (EAR) is defined as:

Average requirement for a group Signup and view all the answers

What does the Recommended Nutrient Intake (RNI) indicate?

Sufficient for 97% of the population Signup and view all the answers

What is the purpose of the Upper Limit (UL) in DRI?

To prevent adverse effects from excessive intake Signup and view all the answers

TDEE is calculated using which formula?

TDEE = BMR + Non-exercise activity + Exercise + DIT Signup and view all the answers

Which of the following components contributes to Total Daily Energy Expenditure (TDEE)?

Basal metabolic rate (BMR) and physical activity Signup and view all the answers

What is Diet-Induced Thermogenesis (DIT)?

Additional energy expenditure after meals Signup and view all the answers

Approximately what percentage of BMR does DIT account for?

10% Signup and view all the answers

What does Basal Metabolic Rate (BMR) measure?

Energy consumed at rest Signup and view all the answers

What is the average BMR per kilogram of body weight?

24 kcal/kg/day Signup and view all the answers

Study Notes

Learning Outcomes

Ability to describe healthy diet composition and caloric content.
Understanding of energy balance principles within the body.
Knowledge of Basal Metabolic Rate (BMR) and diet-induced thermogenesis (DIT).
Explanation of Daily Energy Expenditure (DEE).
Familiarity with Dietary Reference Intakes (DRI).
Overview of Total Parenteral Nutrition (TPN).
Recognition of essential dietary factors and nutritional deficiency consequences.

A Healthy Diet

Focus on fruits, vegetables, and whole grains.
Inclusion of fat-free or low-fat dairy products.
Incorporates lean meats, poultry, fish, beans, eggs, and nuts.
Emphasizes foods low in saturated fats, cholesterol, and added sugars.

Important Principles of Nutrition

Adequacy: Sufficient essential nutrients intake.
Balance: Avoid reliance on a single food type.
Energy Control: Prevent overeating and undereating.
Moderation: Maintain appropriate quantities of food.
Variety: Include a diversity of foods for nutrition.
Encourage healthy weight maintenance and physical activity for 30-60 minutes daily.

Nutrient Classification

Macronutrients: Required in large quantities (g).
- Includes carbohydrates, fats, and proteins.
Micronutrients: Needed in smaller amounts (mg).
- Includes vitamins and minerals.

Energy Yielding Nutrients

Carbohydrates: Organic compounds that provide energy; includes sugars (sucrose, lactose, glucose) and starches.
Lipids (Fats): Triglycerides yield more energy during oxidation; essential for growth and critical illness recovery.

Vitamins and Minerals

Vitamins: Organic, divided into water-soluble (B vitamins, Vitamin C) and fat-soluble (Vitamins A, D, E, K); deficiencies can cause diseases.
Macro-minerals: Required above 100 mg/day; examples include calcium, phosphorus, potassium, and magnesium.
Micro-minerals: Essential in small amounts; include iron, zinc, and iodine.

Energy Units

Caloric intake measured in kilocalories (kcal); SI unit is kilojoule (kJ).
Energy content per gram: Carbohydrates 4.0 kcal, Protein 4.0 kcal, Fat 9.0 kcal, Alcohol 7.0 kcal.

Basal Metabolic Rate (BMR)

Energy expended at rest, awake, in a neutral environment, 12 hours after eating.
Roughly 24 kcal/kg of body weight daily; varies with age, sex, and health status.

Daily Energy Expenditure (TDEE)

Total calories burned in a day, including BMR, physical activity, and thermic effect of food (about 10% of BMR).
Maintains weight balance: Energy intake equals energy expenditure.

Dietary Reference Intakes (DRI)

Reference values for nutrient intake used in assessing diets for populations.
Include Lower Reference Nutrient Intake (LRNI), Estimated Average Requirement (EAR), Recommended Dietary Allowance (RDA), and Upper Limit (UL).

Total Parenteral Nutrition (TPN)

Clinical practice of administering nutrition intravenously, bypassing the digestive system.
Nutritional components: water, glucose, salts, amino acids, and vitamins.

Body Mass Index (BMI)

Formula: BMI = body weight (kg) ÷ height (m²).
Identifies obesity risks and correlates with body fat percentage.
Example calculation for 72 kg weight and 1.83 m height yields a BMI of 21.5 kg/m².

Principles of Nutrition

Adequacy involves consuming sufficient amounts of all essential nutrients.
Balance emphasizes not depending solely on one food type for nutrition.
Energy control focuses on avoiding both overeating and under-eating.
Moderation suggests maintaining a healthy intake of all food groups, neither too much nor too little.
Variety encourages including a diverse range of foods for overall nutritional benefit.
Aiming for a healthy weight is vital for overall health.
Physical activity should be practiced for 30-60 minutes daily for optimal health.

Regulator Nutrients: Micro-Minerals

Iron (Fe): Critical for biological functions; body content is 2.4g; RDA is 8mg (male), 18mg (female).
Zinc (Zn): Essential for various bodily processes; body content is 1.5 - 2.5g; RDA is 11mg (male), 8mg (female).
Molybdenum (Mo): Unknown body content; RDA is 45mcg.
Selenium (Se): Important for antioxidant functions; body content is 15mg; RDA is 55mcg.
Iodine (I): Required for thyroid function; body content is 15 - 20mg; RDA is 150mcg.
Manganese (Mn): Necessary for bone formation and metabolism; body content is 10 - 20mg; RDA is 2.3mg (male), 1.8mg (female).

Energy Yielding Nutrients and Metabolism

Understanding energy yielding nutrients is essential for assessing metabolism and caloric needs.

Basal Caloric Requirements

Males require approximately 1800 kcal/day to maintain basic metabolic rate (BMR).
Females require approximately 1300 kcal/day for BMR.
Recommended Dietary Allowances (RDA) escalate to 2800 kcal/day (male) and 2100 kcal/day (female) to support daily functions.
Additional caloric intake: +300 during pregnancy and +500 during lactation.

BMI Ranges

Body Mass Index (BMI) is a measure used for assessing body weight relative to height, indirectly indicating healthy weight ranges.

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Description

This quiz focuses on the principles of nutrition as covered in the DEM Year 2 course at RCSI. Students will describe the composition and caloric content of a healthy diet, explain energy balance, and discuss BMR and thermogenesis. Prepare to test your understanding of these foundational concepts in gastrointestinal biology.