Nutrition Energy and Weight Management Practice Questions.

What is metabolism?

The sum of all chemical reactions in the body

Which of the following are energy sources?

Carbohydrates, fats, proteins, and alcohol

Which organ is the primary site of metabolism?

Liver

What do muscle cells primarily store and use for energy?

Glycogen

The brain and central nervous system primarily depend on which energy source?

Glucose

Where does glycolysis occur?

Cytoplasm

Where does fatty acid oxidation take place?

Mitochondria

What is the end product of glycolysis under aerobic conditions?

Acetyl CoA

What happens to excess Acetyl CoA when energy demand is low?

Converted into fatty acids and stored as fat

What happens to proteins during metabolism?

They are broken down into amino acids, which enter different metabolic pathways

What does ATP stand for?

Adenosine Triphosphate

How is ATP formed from ADP?

By adding a phosphate group

Which process generates the most ATP?

Electron Transport Chain

What is the primary function of ATP?

Store and transfer energy

ATP provides energy for which of the following?

All of the above

Which process builds complex molecules using energy?

Anabolism

Which of the following is a catabolic reaction?

Glycolysis

What happens in a catabolic state?

The body breaks down molecules to produce energy

Which condition is associated with increased catabolism?

Degenerative diseases like cancer and HIV

Which of the following is an anabolic process?

Glycogen synthesis

What is the first step of carbohydrate metabolism?

Glycolysis

Mitochondria

Fatty acids are broken down into Acetyl CoA in mitochondria.

Low oxygen availability

Lactic acid is formed. Without oxygen, pyruvate is converted into lactic acid.

Deamination

Remove nitrogen from amino acids. Deamination removes nitrogen so that amino acids can enter metabolism.

TCA Cycle

The TCA cycle produces energy through oxidation of Acetyl CoA.

Acetyl CoA

Enter the TCA cycle to produce ATP. Acetyl CoA is a key intermediate in energy production.

Excess Acetyl CoA

Converted into fat. When energy needs are met, Acetyl CoA is stored as fat.

NADH

NADH carries electrons to the Electron Transport Chain.

Electron Transport Chain

The primary site of ATP production.

Energy surplus

Excess energy is stored as fat. The body stores excess energy for future use.

Carbohydrates during feasting

Stored as glycogen, then converted to fat if excess. The body first stores carbohydrates as glycogen, but excess is turned into fat.

Excess dietary fat storage

Directly as fat. Unlike carbohydrates, fats do not need conversion and are stored directly.

Protein in excess

Used for body needs first, then stored as fat. Protein is used for repair and maintenance before being converted to fat.

Primary fuel source in fasting

Glycogen stores. Glycogen is the first energy reserve used when food is unavailable.

Metabolic change after 24 hours of fasting

Fat breakdown increases, and ketones are produced. The body begins breaking down fat for energy, producing ketones.

Purpose of ketosis

Provide an alternative energy source to glucose. Ketones serve as a backup fuel for the brain when glucose is low.

Muscle tissue during prolonged fasting

Protein is broken down for glucose. When glycogen is depleted, the body starts breaking down muscle for energy.

Risk of prolonged fasting

Slow metabolism and muscle loss. Long-term fasting reduces muscle mass and lowers metabolic rate.

Fasting and the immune system

Weakens it due to lack of nutrients. Without essential nutrients, immune function declines.

Ketosis as a long-term energy source

Can lead to nutrient deficiencies and cognitive issues. Ketosis is a survival mechanism, not a sustainable energy system.

Alcohol metabolism

Liver. The liver processes alcohol and converts it into Acetyl CoA.

Alcohol intake exceeds liver capacity

Alcohol remains in the bloodstream, causing intoxication. The liver can only process a certain amount at a time.

Alcohol

Remains in the bloodstream, causing intoxication.

Acetaldehyde

A harmful byproduct of alcohol metabolism that is toxic and contributes to hangover symptoms.

NADH levels

Increases NADH, preventing Acetyl CoA from entering the TCA cycle, disrupting normal metabolism and leading to fat accumulation.

Fatty liver disease

A long-term effect of excessive alcohol consumption, where chronic alcohol use leads to fat buildup in the liver.

Abdominal fat storage

Increases due to excess alcohol, which is linked to increased fat deposits in the abdomen.

Dehydration caused by alcohol

Alcohol inhibits the release of antidiuretic hormone (ADH), leading to excessive urination and dehydration.

Calories in alcohol

Alcohol provides 7 kcal per gram, but it is not a nutrient.

Empty calories

Alcohol is considered 'empty calories' because it provides energy but lacks essential nutrients.

Fat metabolism

Slows down due to the body's prioritization of alcohol metabolism, delaying fat breakdown.

ATP

The body's main energy currency used for energy transfer.

Excess energy intake

Stored as fat, regardless of source.

Basal Metabolic Rate (BMR)

The energy used at rest for basic functions, accounting for most of the body's energy use.

Lean muscle mass

The factor that most influences BMR, as more muscle increases energy expenditure at rest.

Thermic Effect of Food (TEF)

Energy used for digestion and absorption, accounting for 5-15% of daily energy use.

Macronutrient with highest TEF

Protein, which requires more energy to digest than fats or carbohydrates.

Calories in 1 pound of fat

3,500 kcal; a daily 500 kcal deficit leads to 1 pound of fat loss per week.

Weight maintenance

Mainly influenced by caloric balance (intake vs. expenditure); to maintain weight, calories in must equal calories out.

Non-Exercise Activity Thermogenesis (NEAT)

Increased by activities such as walking and fidgeting, including all non-exercise physical activity.

Sleep and metabolism

BMR is lowest during sleep; metabolism slows down at rest, but sleep is essential for regulation.

Body fat percentage

A more accurate measure of health than BMI, as BMI does not distinguish between fat and muscle.

Body fat distribution

Apple shape (central obesity) is most associated with health risks, increasing risks of diabetes and heart disease.

Waist circumference

A larger waist indicates higher risk of metabolic diseases, helping predict health risks beyond BMI.

Gender and body fat percentage

Women naturally have a higher body fat percentage, requiring more fat for reproductive functions.

Health risk of too little body fat

Hormonal imbalances and infertility can occur due to low fat levels disrupting hormone production.

Which measurement technique is most accurate for body fat percentage?

c) DEXA scan

Why can BMI misclassify individuals?

a) It does not account for muscle mass

What body fat percentage is considered obese for men?

c) 25% or higher

How can body composition be improved?

b) Increase muscle while decreasing fat

What is a consequence of visceral fat accumulation?

c) Increased risk of cardiovascular disease

Convert 150 pounds to kilograms. (1 lb = 0.4536 kg)

a) 60.8 kg

If a person weighs 62.7 kg, what is their BMR (for a woman)?

a) 1,354 kcal/day

Calculate the daily calorie deficit needed to lose 1 lb per week.

a) 500 kcal

How many grams of protein would you consume if you eat 6 oz of chicken (1 oz = 28.35 g, 1 oz of chicken = 7 g protein)?

a) 42 g

Convert 200 kcal to joules. (1 kcal = 4.184 kJ)

a) 836.8 kJ

Sarah's maintenance calorie requirement is 2,400 calories per day. She wants to lose 1 pound per week. What should her new daily calorie intake be?

a. 1,900

John currently consumes 3,200 calories per day to maintain his weight. He aims to lose 2 pounds per week. What is his target daily calorie intake?

b. 2,200

Tom needs 2,600 calories to maintain his weight. If he wants to lose 1 pound per week, what should his daily calorie intake be?

c. 2,100

Emily wants to lose 2 pounds per week. Her daily maintenance intake is 2,000 calories. What should her new daily intake be?

a. 1,000

Chris is eating 2,500 calories daily to maintain his current weight. He wants to lose 1 pound per week. How many calories should he consume per day?

b. 2,000