Energy of Food: Nutrition

Ms. HanlinPrairie School

Carbohydrate YES Protein YES Fat YES

Vitamins NO Minerals NO Water NO

Which of the following provide energy?

Energy: The capacity to do work. Is not created or destroyed, only transformed.

Food Energy: Amount of energy in food that is available through digestion.

Calorie: The unit used to measure energy

◦ A kilocalorie is a unit of energy ◦ 1,000 heat calories in 1 food Calorie

Energy Review

Caloric ValuesFood joules/grams calories/gram Calories/gram

Protein 17 000 4000 4

Fat 38 000 9000 9

Carbohydrates 17 000 4000 4

Smoot, Smith, Price, Chemistry A Modern Course, 1990, page 51

1000 calories = 1 Calorie"science" "food"

1calories = 4.184 joules

Calories per gram, found from bomb calorimeter experiments.

Fat is the most energy dense food.

Energy from types of foods

Only carbohydrates (including fiber), fats, proteins, organic acids, and ethanol contain food energy.

• Everything else in food is non-caloric, including water, vitamins, minerals, antioxidants, caffeine, and natural flavors. Tea and coffee also have no calories without sugar or milk added

Food Energy

By using 'Atwater factors‘ it is easy to calculate the energy in any food,

• If you know the number of grams of carbohydrate, fat, and protein in a food, you can calculate the number of calories in it.

For example, a deluxe fast-food burger contains about 45 grams of carbohydrate, 27 grams of protein, and 39 grams of fat.

45 X 4=18039 X 9 = 35127 X 4 = 108 TOTAL = 639 Calories or 639,000

calDivide each number by total to get percent of each

nutrient in your diet. Ex. 180/639= 28 % Carbohydrate

1. Basal metabolic rate: When a subject at at rest and only energy requirements to sustain life are performed. ◦ 60-70% of food energy goes to this◦ An additional 5-10% for metabolizing nutrients◦ An additional 7% to maintain body temperature in

cold condition

We need energy for…

Keeping BMR high is important for weight loss and maintaining healthy fat levels. ◦ EXERCISEINCREASES BMR◦ SOME HORMONESINCREASE BMR◦ AGEBMR DECRESES WITH AGE◦ PROTEIN RICH FOODSINCREASE BMR◦ MALES HAVE HIGHER BMR THAN FEMALES◦ PREGNANCYINCREASES BMR◦ COLD WEATHER INCREASES BMR◦ STARVATIONGREATLY DECREASES BMR (UP TO

50%)

Basal Metabolic Rate

Next class we will find the calories in a marshmallow and cheeto by burning each and calculating the heat produced.

Remember, heat is just a transfer of energy ENERGY is what your calories come from.

How to determine calories in foods

Find the total Calories, the Calories of fat, carbohydrates and protein of each of the substances we will test (cheeto and marshmallow) ◦ Due tomorrow before lab◦ Can work in pairs to solve

Tomorrow: Food Calorimetric Lab!!!

Homework: Pre Lab Questions