Basic Calculations



Problem #1

Calculate number of kcal  from Protein , CHO and fat in diet that contains:
150 gm CHO
45 gm Fat
60 gm Protein
100 gm Alcohol 
30 gm Cholesterol

Solution:
A) Determine # of Kcal provided by each nutrient

1) CHO provides            4 kcal/gm
2) Fat   provides          9 Kcal/gm
3) Protein provides        4 kcal/gm
4) Alcohol provides        7 kcal/gm
5) Cholesterol provides    0 kcal/gm  

B) Multiply # of grams of each nutrient by corresponding # of kcal provided by it  
   150 gm CHO          x 4 = 600 kcal
   45 gm Fat           x 9 = 405 kcal
   60 gm Protein       x 4 = 240 kcal
   100 gm Alcohol      x 7 = 700 kcal
   30 gm Cholesterol   x 0 = 0 kcal

C) To get total # of kcal provided by this meal add all kcal together 
      600 + 405 + 240 + 700 + 0  = 1945 Kcal

Now try it your own:

1)Example Calculate number of kcal  from Protein , CHO and fat in diet that contains:

180 gm CHO
60 gm Fat
50 gm Protein
70 gm Cholesterol

2)Example Calculate number of kcal  from Protein , CHO and fat in diet that contains:

165 gm CHO
35 gm Fat
90 gm Protein
200 gm Alcohol      
70 gm Cholesterol



Solution :
Ex 1) = 1950 Kcal
Ex 2) = 2735 Kcal

Problem #2

Calculate the percent contribution of Kcal from Protein , CHO and fat in diet that contains

150 gm CHO
45 gm Fat
60 gm Protein
100 gm Alcohol 
30 gm Cholesterol

Solution:
1)Find out total # of Kcal provided by this diet.
  This is what we have practiced so far in previous examples:  

A) Determine # of Kcal provided by each nutrient
6) CHO provides 4 kcal/gm
7) Fat   provides 9 Kcal/gm
8) Protein provides 4 kcal/gm
9) Alcohol provides 7 kcal/gm
10)Cholesterol provides 0 kcal/gm  

B) Multiply # of grams of each nutrient by corresponding # of kcal provided by it  
   150 gm CHO          x 4 = 600 kcal
   45 gm Fat           x 9 = 405 kcal
   60 gm Protein       x 4 = 240 kcal
   100 gm Alcohol      x 7 = 700 kcal
   30 gm Cholesterol   x 0 = 0 kcal

C) To get total # of kcal provided by this meal add all kcal together 
      600 + 405 + 240 + 700 + 0  = 1945 Kcal

2)Take the # of Kcal provided by the nutrient which % in diet you want to determine
  and divide it by total # of kcal provided by this diet. To get the answer in % just   
  multiply the result by 100. 

600 kcal / 1945 Kcal  = 0.308 x 100 = 30.84% = 31%
400 Kcal / 1945 Kcal  = 0.205 x 100 = 20.5%  = 21%
240 Kcal / 1945 Kcal  = 0.123 x 100 = 12.3%  = 12%
700 Kcal / 1945 Kcal  = 0.35  x 100 = 35%

  To check your answer just add all the % together. Te resulting # should be 100%. 
It will not be exactly 100% if you were rounding off.

Now try it on your own.
For the following examples we will use our examples 1 and 2 

Example 3)
Calculate the percent contribution of Kcal from Protein , CHO and fat in diet that contains

180 gm CHO
60 gm Fat
50 gm Protein
70 gm Cholesterol


Example 4)

165 gm CHO                  
35 gm Fat
90 gm Protein
200 gm Alcohol      
70 gm Cholesterol



Solution:

Example 3)
 CHO        = 37%
 Fat        = 28%
 Protein    = 10%
 Alcohol    = 25%


Example 4)

 CHO            = 24% 
 Fat            = 12%
 Protein        =13%
 Alcohol        = 51%      

Are these diets healthy diets? Explain why yes or why not? Give specific recommendations
For individual nutrients.


 Additional calculation problems: 

1) If a food contains 380 Kcal and 15 g fat, what % of the Kcal are from fat?
2) If a food contains 150 Kcal and 15 g CHO, what % of the Kcal are from fat?
3) If a food contains 200 Kcal and 18 g prot, what % of the Kcal are from fat?

Solution:
1) 15 g    x  9Kcal      = 135 Kcal
   135Kcal / 380 Kcal = 0.355 x 100 = 35.5% = 36%

2) 40%

3) 36%



Problem #3


Calculation of protein need

Calculate the protein need in  grams for 220lb male:

Solution
1)Convert pounds into Kg  1Lb = 2.2 kg
  220 / 2.2 = 100 kg 
2)Multiply weight in Kg by protein recommendation which 0.8 g/kg
  100 x 0.8 = 80g

This man’s protein need is 80 grams 

Now try it on your own:

Example 5)Calculate protein need in grams for 180lb female:

Solution:
        This woman’s protein need is 65 grams