Macro Coach Certification Macronutrient Science Fundamentals 2 — Questions and Answers

Question 1: Which of the following best describes the role of insulin in carbohydrate metabolism?

Insulin breaks down glycogen in the liver to release glucose
Insulin facilitates glucose uptake into cells and promotes glycogen synthesis, reducing blood glucose levels (Correct answer)
Insulin stimulates fat breakdown (lipolysis) during high carbohydrate intake
Insulin converts amino acids into glucose during a caloric surplus

Correct answer: Insulin facilitates glucose uptake into cells and promotes glycogen synthesis, reducing blood glucose levels

Insulin is secreted by the pancreas in response to elevated blood glucose. It facilitates glucose uptake into muscle and fat cells, promotes glycogen synthesis, and signals energy storage.

After carbohydrate consumption, blood glucose rises. The pancreas releases insulin, which binds to cell receptors and enables GLUT4 transporter activation, allowing glucose to enter muscle cells (for glycogen synthesis) and adipose cells (for fat synthesis). Insulin also inhibits lipolysis (fat breakdown), gluconeogenesis (liver glucose production), and glycogenolysis. During a caloric surplus with adequate carbohydrates, insulin promotes energy storage. Insulin sensitivity — how effectively cells respond to insulin — is a critical factor in body composition and metabolic health, improved by resistance training and adequate sleep.

Question 2: Complete proteins differ from incomplete proteins in that they:

Contain more calories per gram
Provide all nine essential amino acids in adequate quantities (Correct answer)
Are only found in animal sources
Are absorbed faster than incomplete proteins

Correct answer: Provide all nine essential amino acids in adequate quantities

Complete proteins contain all nine essential amino acids (EAAs) — those the body cannot synthesize and must obtain from food — in sufficient quantities to support protein synthesis.

Essential amino acids (EAAs) are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine. The body cannot synthesize these, so they must come from food. Complete proteins (animal sources: meat, eggs, dairy; also quinoa, soy, hemp) provide all nine EAAs. Incomplete proteins (most plant sources: beans, rice, nuts) are low in one or more EAAs (e.g., legumes lack methionine; grains lack lysine). Vegans can combine complementary proteins (rice + beans) throughout the day to achieve complete EAA coverage — they don't need to be combined in the same meal.

Question 3: The Thermic Effect of Food (TEF) refers to:

The temperature at which food must be cooked to prevent bacterial growth
The increase in metabolic rate following food consumption to digest, absorb, and metabolize nutrients (Correct answer)
The calories added to food during cooking
The rate at which food spoils at room temperature

Correct answer: The increase in metabolic rate following food consumption to digest, absorb, and metabolize nutrients

TEF is the energy expenditure required to digest, absorb, and process food. Protein has the highest TEF (20–30%), followed by carbohydrates (5–10%), then fat (0–3%).

TEF (also called dietary-induced thermogenesis) accounts for approximately 10% of total daily energy expenditure. Protein has the highest TEF (20–30% of protein calories are used in digestion and metabolism), which is one reason high-protein diets are effective for fat loss — eating 100 kcal of protein costs 20–30 kcal to process. Carbohydrates: 5–10% TEF. Fat: 0–3% TEF. This means a high-protein diet creates a slight thermogenic advantage over a high-fat or high-carb diet at the same caloric intake. TEF is also why very low protein diets can lead to more fat gain calorie-for-calorie.

Question 4: Which type of dietary fat is associated with increased LDL cholesterol and cardiovascular risk when consumed in excess?

Monounsaturated fats (MUFAs)
Saturated fats (Correct answer)
Polyunsaturated omega-3 fatty acids
Medium-chain triglycerides (MCTs)

Correct answer: Saturated fats

Saturated fats (found in fatty meats, butter, full-fat dairy, coconut oil) are associated with elevated LDL cholesterol, which increases cardiovascular disease risk when consumed in excess.

Saturated fatty acids (palmitic, stearic, lauric acid) are found in animal fats (lard, butter, fatty meat) and tropical oils (palm, coconut). Multiple meta-analyses confirm that replacing saturated fat with polyunsaturated fat reduces LDL cholesterol and cardiovascular events. Monounsaturated fats (olive oil, avocado) are neutral to beneficial. Omega-3 polyunsaturated fats (EPA/DHA from fatty fish) are anti-inflammatory and cardioprotective. For macro coaches, fat quality matters: directing clients to prioritize unsaturated fats while moderating saturated fat intake (ideally <10% of total calories) supports overall health.

Question 5: Glycogen is primarily stored in which two locations in the human body?

Kidneys and pancreas
Liver and skeletal muscle (Correct answer)
Brain and spinal cord
Adipose tissue and bones

Correct answer: Liver and skeletal muscle

Glycogen is stored in the liver (regulates blood glucose, ~100 g capacity) and skeletal muscle (fuels muscle contraction, ~300–500 g capacity in trained individuals).

The body stores approximately 400–500 g of glycogen total. Liver glycogen (~100 g) is released into the bloodstream to maintain blood glucose homeostasis between meals and during fasting. Muscle glycogen (~300–400 g in average adults, up to 600+ g in trained athletes) is used exclusively as fuel for the muscle that stored it — it cannot be released into the blood. Carbohydrate availability significantly affects high-intensity exercise performance. When muscle glycogen depletes (endurance events, prolonged high-intensity training), performance drops dramatically — this is known as 'hitting the wall' or 'bonking.'

Question 6: Branched-chain amino acids (BCAAs) include leucine, isoleucine, and valine. Which BCAA plays the most critical role in stimulating muscle protein synthesis (MPS)?

Valine
Isoleucine
Leucine (Correct answer)
All three equally

Correct answer: Leucine

Leucine is the primary activator of mTORC1 signaling, the key pathway for initiating muscle protein synthesis. It acts as a 'trigger' for MPS, making it the most critical amino acid for muscle building.

Of the three BCAAs, leucine uniquely activates the mTORC1 (mechanistic target of rapamycin complex 1) signaling pathway, which is the primary regulator of muscle protein synthesis. Research by Norton, Layman, and others demonstrates that leucine content of a meal (typically 2–3 g leucine threshold) determines whether MPS is maximally stimulated, regardless of total protein content. Foods highest in leucine: whey protein, animal meats, eggs, dairy. This is why whey protein is highly effective for post-workout MPS. Plant proteins often have lower leucine content, requiring higher total protein intake to achieve the same MPS response.

Macro Coach Certification Macronutrient Science Fundamentals 2

Which of the following best describes the role of insulin in carbohydrate metabolism?