Ms. Hanlin Prairie School

 Carbohydrate YES  ProteinYES  FatYES  VitaminsNO  MineralsNO  WaterNO

 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

Caloric Values Food joules/grams calories/gram Calories/gram Protein Fat Carbohydrates Smoot, Smith, Price, Chemistry A Modern Course, 1990, page calories = 1 Calorie "science" "food" 1calories = joules

 Calories per gram, found from bomb calorimeter experiments.  Fat is the most energy dense food.

 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

 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=180  39 X 9 = 351  27 X 4 = 108 TOTAL = 639 Calories or 639,000 cal  Divide 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

 Keeping BMR high is important for weight loss and maintaining healthy fat levels. ◦ EXERCISE  INCREASES BMR ◦ SOME HORMONES  INCREASE BMR ◦ AGE  BMR DECRESES WITH AGE ◦ PROTEIN RICH FOODS  INCREASE BMR ◦ MALES HAVE HIGHER BMR THAN FEMALES ◦ PREGNANCY  INCREASES BMR ◦ COLD WEATHER  INCREASES BMR ◦ STARVATION  GREATLY DECREASES BMR (UP TO 50%)

 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.

 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!!!