Practice Calculations:
Alicia ate a meal that contained 42 grams of carbs, 35 grams of protein and 10 grams of fat. What
percentage of her meal was carbohydrate, protein and fat.
Step 1: Multiple each macronutrient by the number of calories per gram
- 42 grams of carbs x 4 calories/gram = 168 calories
- 35 grams of protein x 4 calories/gram = 140 calories
- 10 grams of fat x 9 calories/gram = 90 calories
Step 2: Add the calories from all three macronutrients
-
168 + 140 + 90 = 398 calories
Step 3: Divide the calories from each nutrient by the total number of calories in the meal
-
168 calories from carbs / 398 total calories = 0.42 or 42%
140 calories from protein / 398 total calories = .035 or 35%
90 calories from fat / 398 total calories = 0.22 or 22%
Step 4: Double check your work
-
Add the percentages together to get 100% = 42% +35% +22%
Kristy (155 lbs) is trying a new diet that provides 1200 calories. She is eating 20% carbs, 50% protein and
30% fat. Is Kristy getting the minimum of 130 grams of carbs/day? Is she consuming more than the
recommended 0.8 grams protein/kg? Is she getting more than the recommended maximum of 2 g
protein/kg per day?
Step 1: Determine how many calories each macronutrient percentage is providing
-
1200 calories x 20% (0.20) carbohydrates = 240 calories from carbs
1200 calories x 50% (0protein = 600 calories from protein
1200 calories x 30% fat = 360 calories from fat
Step 2: Divide the calories from each nutrient by the calories/gram each macronutrient provides
-
240 calories from carbs / 4 calories/gram = 60 grams of carbs (she is not getting the minimum
130 grams/day)
600 calories from protein / 4 calories/gram = 150 grams of protein
360 calories from fat / 9 calories/gram = 40 grams of fat
Step 3: Find Kristy’s weight in kilograms
-
Weight in lbs / 2.2 kg = wt in kg
-
155 lbs / 2.2 kg = 70.5 kg
Step 4: Determine how many grams /kg body weight Kristy is consuming
-
Total grams of protein / weight in kg
150 grams of protein / 70.5 kg = 2.12 grams/kg
Kristy is eating too much protein. She meets the minimum but has exceeded the maximum
Mike is trying to increase his calcium. He drank 2 cups of milk (each providing 300 mg calcium), had one
cup of yogurt (250 mg calcium), and 1 cup broccoli (60 mg calcium) today. He needs 1300 mg/day. What
percentage of his daily recommend calcium did he consume?
Step 1: Calculate how much calcium he ate total
-
2 cups of milk with each 300 mg = 600 mg calcium
1 cup yogurt = 250 mg calcium
1 cup broccoli = 60 mg calcium
600 + 250 + 60 = 910 mg calcium
Step 2: Determine his daily % value
-
910 mg calcium intake / 1300 mg calcium recommended = 0.7 or 70% (Mike needs to consume
more calcium)
Dwight is a strength athlete and is consuming 150 grams of protein /day. What is his weight in lbs if he is
consuming 1.6 grams of protein/kg? How much weight will he need to gain/lose to meet his goal of 215
lbs?
Step 1: Determine his weight in kilograms
-
150 grams of protein/day divided by 1.6 grams of protein/kg = 93.75 kg
Step 2: Determine his weight in pounds
-
93.75 kg x 2.2 kg/lb = 206 lbs
Step 3: Determine the difference between current weight and goal
-
215 lb goal – 206 lb currently = 9 lbs to gain
Super tough!! If you get this, you’ll get any math question on the test (however I will not make them this
tough)
Drew is 160 lbs and eating 1800 calories. He is eating 900 calories from carbohydrates, 25% fat and 1.54
grams protein/kg body weight. Provide the total calories and %of calories for each macronutrient.
Step 1: Determine how many calories/grams from 25% fat
-
1800 total calories x 25% fat = 450 calories from fat
450 fat calories/ 9 cal/gram = 50 grams of fat
Step 2: Determine grams of carbohydrates and % of calories
-
900 calories from carbs / 4 cal/gram = 225 grams from carbs
900 calories from carbs / 1800 total calories =50% carbs
Step 3: Determine how much protein is being eaten in grams, calories and percent
-
Find weight in kilograms = 160 lbs/2.2 kg per lb = 72.7 kg
72.7 kg x 1.54 grams protein/kg = 112 grams of protein
112 grams of protein x 4 cal/gram = 448 calories (we can round to 450 calories)
450 calories from protein / 1800 calories = 25% protein
Step 4: Add all the calories, grams and percents together.
-
900 calories from carbs + 450 calories from fat + 450 calories from protein = 1800 calories
50 grams of fat, 225 grams of carbs, 112 of grams of protein
25% fat, 50% carbs, 25% protein