Nutrition Energy Quiz

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Questions and Answers

What percentage of carbohydrates, fats, and proteins are typically digested in the body?

97% for carbohydrates, 96% for fats, 89% for proteins

98% for carbohydrates, 95% for fats, 92% for proteins (correct)

98% for carbohydrates, 95% for fats, 90% for proteins

95% for carbohydrates, 92% for fats, 90% for proteins

What is energy primarily defined as in this context?

The amount of heat produced

The movement of particles

The capacity to burn fuel

The ability to do work (correct)

Which of the following components does not belong to the energy expenditure components?

Vigorous exercise (correct)

Basal metabolic rate

Thermic effect of food

Physical activity

What is required for measuring the basal metabolic rate properly?

Post absorptive stage and reclining position Signup and view all the answers

Which nutrient is NOT classified as an energy-yielding nutrient?

Vitamins Signup and view all the answers

How is one kilocalorie defined?

Amount of heat to raise the temperature of 1kg of water by 1°C Signup and view all the answers

Which factor does not significantly affect the basal metabolic rate?

Surrounding humidity Signup and view all the answers

What unit has recently been adapted by IUNS to replace kilocalories in nutrition?

Joule Signup and view all the answers

How much higher is the basal metabolic rate in an athletic male compared to a non-athletic male?

6% Signup and view all the answers

What method is primarily used to determine the energy value of food?

Direct calorimetry Signup and view all the answers

What is the primary function of the basal metabolic rate?

Energy required for involuntary body processes Signup and view all the answers

What is the primary purpose of a bomb calorimeter?

To measure heat produced by burning food Signup and view all the answers

In terms of energy expenditure, which component accounts for the energy used in digesting food?

Thermic effect of food Signup and view all the answers

Which gender generally has a higher percentage of adipose tissue compared to muscle tissue?

Young adult females Signup and view all the answers

What is the main limitation of using a bomb calorimeter?

It takes a long time to operate Signup and view all the answers

What is the primary measurement used in indirect calorimetry to determine energy needs?

Oxygen consumption Signup and view all the answers

Which of the following is true about the conversion factor between kilocalories and joules?

1 kcal = 4.184 kJ Signup and view all the answers

What does the term 'gross energy value' refer to?

The energy determined from complete oxidation of food Signup and view all the answers

What is the equation used to calculate metabolizable energy?

GE - losses = ME Signup and view all the answers

What is the coefficient of digestibility for protein?

0.92 Signup and view all the answers

Which of the following statements is true about the physiological fuel values of nutrients?

There is no loss of energy in the metabolism of carbohydrates and fats. Signup and view all the answers

What happens to the energy from fiber in vegetable foods when digested?

It contributes to the gross energy value but not the physiological fuel value. Signup and view all the answers

In indirect calorimetry, what is recirculated after carbon dioxide and water are removed?

Nitrogen and oxygen Signup and view all the answers

Which nutrient has a physiological fuel value of 9 kcal?

Fats Signup and view all the answers

What is the percentage increase in BMR during the last trimester of pregnancy?

12% Signup and view all the answers

How does prolonged calorie undernutrition affect BMR?

Decreases BMR by 20-30% Signup and view all the answers

What adaptive response occurs to increased environmental temperature?

Increased Sweating Signup and view all the answers

What effect does smoking have on BMR?

Increases BMR by 10% Signup and view all the answers

How does psychological state influence energy expenditure?

Increases energy expenditure during acute anxiety Signup and view all the answers

Which pharmacological agent is known to decrease energy expenditure?

Beta-blockers Signup and view all the answers

Which factors affect the variation of BMR among individuals?

Genetic factors Signup and view all the answers

What physiological condition can significantly increase metabolic rate?

Fever or burns Signup and view all the answers

What factor contributes to the lower BMR in women compared to men of the same age, height, and weight?

Muscle mass differences Signup and view all the answers

At what stage of life is the BMR highest?

Early childhood Signup and view all the answers

How does body temperature impact BMR?

It increases BMR by 13 percent for each degree Celsius above 37°C. Signup and view all the answers

What is the impact of sleep on basal metabolic rate?

BMR is about 10 percent lower during sleep. Signup and view all the answers

Which gland secretes the hormone that significantly stimulates metabolism?

Thyroid gland Signup and view all the answers

How does surface area relate to basal metabolism?

Larger surface area is associated with higher BMR. Signup and view all the answers

What happens to BMR during hypothyroidism?

It may be depressed by as much as 30 percent. Signup and view all the answers

What change occurs in BMR as a person ages past 21 years?

It decreases by about 2 percent per decade. Signup and view all the answers

Study Notes

Energy Fundamentals

Energy is defined as the capacity to perform work.
Food yields energy through combustion, producing CO2, H2O, and energy.
Carbohydrates and fats primarily release energy, while proteins produce energy and urea upon combustion.

Energy Yielding Nutrients

Energy yielding nutrients include carbohydrates, fats, and proteins.
These nutrients are essential for metabolic processes and physical activity.

Units of Energy

Energy content in food is expressed in kilocalories (kcal).
1 kilocalorie raises the temperature of 1 kg of water by 1°C.
Joules (J) is now favored as the energy unit in nutrition; 1 kcal is equivalent to 4.184 kJ.

Measuring Energy Value

Direct calorimetry uses a bomb calorimeter to measure heat from food combustion, providing an accurate energy estimate.
Indirect calorimetry estimates energy needs by monitoring oxygen consumption in a closed-circuit system.

Gross Energy Value and Metabolizable Energy

Heat of combustion (gross energy value) is the total energy from food oxidation.
Metabolizable energy (ME) accounts for energy losses through waste, calculated as: GE - losses = ME.

Physiological Fuel Value

Physiological fuel value is the actual energy available to the body from nutrients post-digestion.
Coefficient of digestibility indicates how much of a nutrient is absorbed: carbohydrates (0.98), fats (0.95), proteins (0.92).
Atwater Bryant factors quantify usable energy: carbohydrates (4 kcal), fats (9 kcal), proteins (4 kcal).

Components of Energy Expenditure

Energy expenditure consists of three components: basal metabolic rate (BMR), physical activity, and the thermic effect of food.

Basal Metabolic Rate (BMR)

BMR represents energy for involuntary body functions, including organ function and maintenance of body temperature.
Influenced by factors such as body composition, gender, age, body size, sleep, and temperature.

Factors Affecting BMR

Body Composition: More muscle increases BMR; fat is less metabolic.
Gender: Men generally have a higher BMR than women.
Age: BMR peaks in early childhood and declines by about 2% per decade after 21.
Body Size: Larger surface area correlates with higher metabolism.
Sleep: BMR decreases during sleep.
Body Temperature: Elevated temperatures can raise BMR.
Hormones: Thyroxine from the thyroid gland significantly influences metabolic rate.

Additional Influences on BMR

Pregnancy: Increased BMR (up to 12%) due to fetal demand.
Nutrition State: Prolonged calorie deficit reduces BMR by 20-30%.
Environmental Temperature: Extreme temperatures increase energy expenditure.
Smoking and Genetics: Smoking can boost BMR; genetic variability affects metabolic rates.
Psychological State: Anxiety can elevate energy expenditure.
Pharmacological Agents: Nicotine and caffeine can increase energy expenditure; beta-blockers may decrease it.
Disease Processes: Certain conditions, like fever or burns, may enhance metabolic rates.

Physical Activity

Following BMR, physical activity significantly contributes to total energy expenditure.
Energy expenditure varies based on work intensity, type of activity, and duration.

Conclusion

Understanding energy components and their influences is crucial for nutritional science and health management.

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Description

Test your knowledge on human nutrition with this quiz focusing on the digestion of carbohydrates, fats, and proteins, as well as energy expenditure components. You'll also explore concepts like basal metabolic rate and energy-yielding nutrients. Perfect for students studying nutrition or dietary sciences!