Chapter 15 Nutrition And Hydration Workbook Answers: Exact Answer & Steps

Chapter 15: Nutrition and Hydration Workbook Answers
Your go‑to guide for mastering the exercise and understanding the concepts behind every question

Opening hook

You’re knee‑deep in the final stretch of your nutrition course, the calculator in your hand ticking down, and the sheet in front of you is a mess of numbers and jargon. You’re staring at a question about protein requirements and a graph on hydration status, and you’re thinking, “I can’t possibly get this right.”
What if the answers were a little more than a cheat sheet? What if they were a roadmap that shows you why the numbers are what they are?
That’s what this post is about—answers that teach Surprisingly effective..

What Is Chapter 15 Nutrition and Hydration Workbook?

The workbook is the practical companion to the lecture material on how the body uses food and water. It’s a collection of problems that stretch your knowledge from macronutrient partitioning to the subtle signals of dehydration. Think of it as a set of drills that sharpen your ability to calculate daily energy needs, interpret lab values, and design meal plans that respect both science and taste.

The Core Themes

• Energy Balance – Calories in versus calories out, thermogenesis, basal metabolic rate.
• Macronutrient Distribution – Protein, carbs, fats: how much, when, and why.
• Micronutrient Focus – Vitamins, minerals, and their role in hydration.
• Fluid Regulation – Body water compartments, electrolytes, and the signs of over‑ or under‑hydration.
• Practical Application – Crafting menus, reading labels, and adjusting for activity levels.

Why It Matters / Why People Care

You might wonder, “Why should I care about the workbook answers?Plus, ” Because the questions are the bridge between theory and practice. When you get the answer, you also get the reasoning that lets you solve new problems on the fly.

• Real‑world relevance: Nutritionists, athletes, and health coaches need to make quick, evidence‑based decisions.
• Academic success: The workbook is often a weighted part of the final grade. A solid grasp means a higher score.
• Long‑term health: Understanding hydration and macronutrient needs helps you maintain a balanced lifestyle beyond the classroom.

How It Works (or How to Do It)

Below is a breakdown of the typical workbook problems, the logic you should apply, and the exact answers for Chapter 15. I’ve kept the math visible so you can see the steps, not just the end result.

1. Calculating Basal Metabolic Rate (BMR)

Question Example:
A 28‑year‑old female weighs 65 kg and is 165 cm tall. What is her BMR using the Mifflin–St Jeor equation?

Answer:
BMR = 10 × weight (kg) + 6.25 × height (cm) – 5 × age (y) – 161
= 10 × 65 + 6.25 × 165 – 5 × 28 – 161
= 650 + 1,031.25 – 140 – 161
≈ 1,380 kcal/day

2. Determining Total Daily Energy Expenditure (TDEE)

Question Example:
Using the BMR above and a sedentary activity factor of 1.2, what’s the TDEE?

Answer:
TDEE = BMR × activity factor
= 1,380 × 1.2
≈ 1,656 kcal/day

3. Macronutrient Distribution

Question Example:
For a 1,800‑kcal diet, what grams of protein, carbs, and fats are recommended if protein should be 15 %, carbs 55 %, and fats 30 % of total calories?

Answer:

• Protein: 0.15 × 1,800 = 270 kcal → 270 ÷ 4 = 67.5 g
• Carbs: 0.55 × 1,800 = 990 kcal → 990 ÷ 4 = 247.5 g
• Fats: 0.30 × 1,800 = 540 kcal → 540 ÷ 9 = 60 g

4. Interpreting Hydration Status

Question Example:
A lab report shows serum osmolality of 310 mOsm/kg and urine specific gravity of 1.020. What does this indicate?

Answer:
Serum osmolality is slightly high (normal 275–295 mOsm/kg), and urine specific gravity is above 1.015, suggesting the body is conserving water. The individual is mildly dehydrated Practical, not theoretical..

5. Fluid Loss During Exercise

Question Example:
A runner loses 0.5 kg of body weight during a marathon. If 90 % of the loss is water, how many milliliters of fluid were lost?

Answer:
0.5 kg × 0.90 = 0.45 kg water = 450 mL (since 1 kg ≈ 1,000 mL) Not complicated — just consistent. That's the whole idea..

Common Mistakes / What Most People Get Wrong

1. Mixing up kcal and kJ – Always double‑check the units.
2. Using outdated activity multipliers – The ACSM tables have been updated; stick to the latest.
3. Assuming 1 g of protein = 4 kcal – That’s true, but remember that not all protein is equally bioavailable.
4. Ignoring electrolytes in hydration – Sodium and potassium are crucial for maintaining plasma osmolality.
5. Over‑relying on weight loss as a hydration marker – Small weight changes can be due to glycogen storage, not just water.

Practical Tips / What Actually Works

• Check the label first – For macronutrient calculations, start with the serving size and multiply.
• Use a simple spreadsheet – Create columns for calories, protein, carbs, fats, and water. It turns abstract numbers into a visual plan.
• Hydrate before you feel thirsty – Thirst is a late signal. Aim for 2–3 L/day, adjusting for sweat loss.
• Track electrolytes – If you’re training hard, add a pinch of sea salt to your water or opt for drinks with 20–30 mEq Na⁺ and 5–10 mEq K⁺.
• Practice with real scenarios – Replace textbook numbers with your own data (e.g., your weight, activity level) to internalize the process.

FAQ

Q1. Can I use the Harris‑Benedict formula instead of Mifflin–St Jeor?
A1. It’s still acceptable, but Mifflin–St Jeor is more accurate for most adults. If you must use Harris‑Benedict, just remember it tends to overestimate BMR by ~10 kcal/day.

Q2. What’s the difference between specific gravity and osmolality?
A2. Specific gravity measures how concentrated urine is compared to water; osmolality measures the total solute concentration in a solution. Both inform hydration status but from different angles.

Q3. How often should I reassess my fluid needs?
A3. At least every time you change training volume or intensity. A 5 % change in sweat rate can shift your fluid requirement by 250 mL/day Easy to understand, harder to ignore. Surprisingly effective..

Q4. Is it okay to drink only water during long runs?
A4. For runs under 90 minutes, plain water is fine. Beyond that, consider an electrolyte solution to prevent hyponatremia.

Q5. Can I cut carbs if I’m on a low‑carb diet?
A5. Yes, but adjust protein and fat to maintain energy balance. Keep in mind carbohydrate is the primary fuel for high‑intensity work Easy to understand, harder to ignore..

Closing paragraph

You’ve got the numbers, the logic, and the tools to turn those workbook questions into real‑world skills. In practice, remember, the goal isn’t just to hit the right answer; it’s to understand the why behind each calculation. Keep practicing, keep questioning, and soon those workbook drills will feel like second nature. Happy solving!