Food Science and Nutrition

1. What is the "glycemic index" (GI) of food?

• A. A measure of food calories
• B. A ranking of foods based on how quickly they raise blood glucose levels — high GI foods cause rapid spikes, low GI foods provide steadier energy ✓
• C. A measure of food's protein content
• D. A food additive classification

💡 The glycemic index (1-100) measures how quickly a food raises blood glucose — white bread scores 75 (high GI), while lentils score 32 (low GI). Important for diabetes management and sustained energy.

2. What are "antioxidants" in food and why are they important?

• A. Chemicals that prevent food from burning
• B. Molecules that neutralize free radicals (unstable atoms that damage cells) — found in colorful fruits, vegetables, and polyphenol-rich foods like berries, dark chocolate, and green tea ✓
• C. Preservatives added to food
• D. Enzymes that digest food

💡 Antioxidants (vitamins C, E, selenium, polyphenols) neutralize free radicals — reactive molecules created by metabolism and environmental stressors that contribute to cell damage, aging, and chronic disease.

3. What is "complete protein" vs "incomplete protein" in nutrition?

• A. Animal protein vs plant protein only
• B. A complete protein contains all nine essential amino acids (meat, eggs, dairy) while incomplete proteins lack one or more (most plants) — combining incomplete proteins achieves completeness ✓
• C. Complete proteins are always healthier
• D. Plant proteins are always incomplete

💡 Essential amino acids (9) cannot be made by the body — complete proteins (meat, eggs, dairy, quinoa, soy) provide all nine. Incomplete proteins (beans, grains) can be combined (rice + beans) to form complete amino acid profiles.

4. What is "intermittent fasting" in nutritional science?

• A. Skipping breakfast only
• B. An eating pattern cycling between periods of fasting and eating — 16:8, 5:2 are common methods, studied for weight management and metabolic health ✓
• C. A starvation diet
• D. Eating only one meal per day

💡 Intermittent fasting (IF) cycles eating and fasting periods — 16:8 (16h fast, 8h eating window) or 5:2 (normal eating 5 days, restricted 2 days). Studies show benefits for weight loss and metabolic health.

5. What causes food to spoil and how does refrigeration prevent it?

• A. Light exposure
• B. Microbial growth (bacteria, mold, yeast) and enzymatic reactions — refrigeration (4°C) slows but does not stop microbial reproduction and enzyme activity ✓
• C. Air exposure only
• D. Water content only

💡 Food spoilage results from bacterial growth (exponential above 4°C), enzymatic breakdown (oxidation, browning), and fungal growth. Refrigeration slows all these processes dramatically without stopping them entirely.

6. What is "food intolerance" vs "food allergy"?

• A. They are the same condition
• B. Food intolerance involves digestive difficulty (like lactose intolerance) without immune response; food allergy involves an immune system reaction that can be life-threatening (like peanut allergy) ✓
• C. Food allergy is less serious
• D. Food intolerance always requires epinephrine

💡 Food allergies trigger IgE-mediated immune responses that can cause anaphylaxis — potentially fatal. Food intolerances (lactose, gluten sensitivity) cause digestive discomfort without immune involvement and are rarely life-threatening.

7. What is the difference between "saturated" and "unsaturated" fats?

• A. One is liquid, one is solid
• B. Saturated fats (solid at room temperature, from animals) have no double bonds; unsaturated fats (liquid, from plants) have one or more double bonds — linked to different health outcomes ✓
• C. Saturated fats are always unhealthy
• D. Unsaturated fats are always healthy

💡 Saturated fats (butter, lard) have all single bonds — solid at room temperature. Unsaturated fats (olive oil, avocado) have double bonds — liquid at room temperature. Saturated fats raise LDL cholesterol more than unsaturated.

8. What is "phytochemical" and why is eating colorful vegetables important?

• A. An artificial food coloring
• B. Natural chemical compounds in plants that provide health benefits — different colors indicate different phytochemicals (red lycopene, orange beta-carotene, purple anthocyanins) ✓
• C. A type of protein in plants
• D. A natural preservative in vegetables

💡 Phytochemicals are plant compounds with biological activity — eating diverse colored vegetables provides different beneficial compounds. "Eat the rainbow" maximizes phytochemical diversity for optimal health.

9. What is "food fortification" and why is it practiced?

• A. Adding extra fat to food
• B. Deliberately adding micronutrients to food that may be deficient in the population — iodine in salt, vitamin D in milk, iron in flour — a public health intervention ✓
• C. Making food taste better
• D. Increasing protein content of food

💡 Food fortification adds nutrients to prevent deficiency diseases — iodized salt prevents goiter, vitamin D fortified milk prevents rickets, folic acid in flour reduces neural tube defects. A major public health success.

10. What is the role of "dietary fiber" in human health?

• A. It provides energy like carbohydrates
• B. Fiber is indigestible plant material that feeds gut bacteria, promotes regularity, lowers cholesterol, and stabilizes blood sugar — soluble fiber dissolves in water, insoluble does not ✓
• C. It is essential for muscle building
• D. It replaces protein in a vegetarian diet

💡 Dietary fiber (soluble and insoluble) supports gut health, feeds beneficial bacteria, slows glucose absorption, lowers LDL cholesterol, promotes satiety, and reduces risk of colorectal cancer.

11. What is "MSG" (monosodium glutamate) and what is the science behind the "MSG myth"?

• A. An artificial chemical unrelated to natural food
• B. A sodium salt of glutamic acid that enhances umami flavor — extensive scientific research has not confirmed "Chinese Restaurant Syndrome," and glutamate is naturally present in tomatoes, Parmesan, and soy sauce ✓
• C. A dangerous food additive banned in most countries
• D. A sugar substitute

💡 MSG (monosodium glutamate) provides umami taste — the "Chinese Restaurant Syndrome" fear was based on anecdotal reports. Controlled scientific studies have found no evidence of adverse effects at normal dietary levels.

12. What is "food irradiation" and is it safe?

• A. Cooking food using radiation
• B. Treating food with ionizing radiation to kill bacteria, insects, and parasites — proven safe by WHO, FDA, and other bodies, used for spices, meats, and some fruits ✓
• C. A form of nuclear contamination
• D. A preservation technique using heat only

💡 Food irradiation uses gamma rays, X-rays, or electron beams to kill pathogens — it does not make food radioactive or significantly alter nutritional value. The WHO, FDA, and EU all consider it safe.

13. What are "probiotics" in food and health?

• A. Vitamins added to food
• B. Live beneficial bacteria and yeasts that support gut health — found in fermented foods like yogurt, kefir, sauerkraut, and kimchi ✓
• C. Artificial preservatives
• D. Fiber supplements

💡 Probiotics are live microorganisms that benefit the host when consumed in adequate amounts — supporting gut microbiome health, immunity, and potentially mental health. Found naturally in fermented foods.

14. What are the three macronutrients essential for human nutrition?

• A. Vitamins, minerals, and water
• B. Fiber, antioxidants, and phytonutrients
• C. Iron, calcium, and potassium
• D. Carbohydrates, proteins, and fats ✓

💡 The three macronutrients are carbohydrates (energy), proteins (building and repair), and fats (energy, hormones, and fat-soluble vitamins) — required in large amounts for bodily functions.