Question

Molecules of Life
Are You What You Eat?
Review the meal options below and pick which option you believe is best for a marathon runner to eat
the night before the big race. Then, justify your answer below with a scientific concept.
Meal A: Baked potato with butter, sour cream, cheese, chives, and bacon
Meal B: Steak and broccoli
Meal C: Meatball spaghetti
Explain your choice in a 9th biology grade mid-term way

Answer 1

Best choice: Meal C — Meatball spaghetti.

Why (9th-grade biology explanation):
- Carbohydrates are the body’s main quick source of energy. Spaghetti is mostly starch (a complex carbohydrate). When you eat it, digestive enzymes break the starch into glucose, which enters the blood.
- Extra glucose is stored as glycogen in your liver and muscles. During a marathon your muscles use that stored glycogen to make ATP by cellular respiration (in the mitochondria). Having full glycogen stores before the race delays fatigue and helps you run longer.
- Meatballs add a moderate amount of protein (good for muscle repair) without making the meal too fatty. A moderate amount of protein is fine the night before; too much fat or very heavy foods slow digestion and can cause stomach problems during the race.
- Compare the other meals: Meal A (baked potato with lots of butter, cheese, sour cream, bacon) has carbs but also a lot of fat, which slows stomach emptying and can lead to discomfort. Meal B (steak and broccoli) is high in protein and fiber but low in carbohydrates, so it won’t refill glycogen stores well.
- In short: spaghetti gives plenty of usable carbohydrates to refill glycogen, is easy to digest compared with a very fatty meal, and helps provide steady energy for the marathon.