A slice of pumpkin bread contains 5 grams of fat 40 grams of

A slice of pumpkin bread contains 5 grams of fat, 40 grams of carbohydrate, and 5 grams of protein. What percent of the bread\'s Calories are from fat Show your work.

Solution

Ans.

#1. Calorific value of fat = 9.0 cal/ gram

            Amount of energy derived from fat = mass of fat x calorific value of fat

                                                            = 5.0 g x (9.0 cal/ gram)

                                                            = 45.0 g

#2. Calorific value of carbohydrate = 4.0 cal/ gram

            Amount of energy derived from carbohydrate =

(mass of carbohydrate x calorific value of carbohydrate)

                                                            = 40.0 g x (4.0 cal/ gram)

                                                            = 160.0 g

#3. Calorific value of protein = 4.0 cal/ gram

            Amount of energy derived from protein =

(mass of protein x calorific value of protein)

                                                            = 5.0 g x (4.0 cal/ gram)

                                                            = 20.0 g

Now,

            Total energy derived from all sources = 45.0 cal + 160.0 cal + 20.0 cal

                                                                        = 225.0 cal

% calorie constitution of fat = (calorie from fat / total calorie in bread) x 100

                                                = (45.0 cal / 225.0 cal) x 100

                                                = 20.0 %