Understanding Calories and Food Energy | December 2009 Epics Food Study

1. Epics food:Calories Week of December 7, 2009

2. EPICS Food: Monday, 12.7.09Calories • Do Now:In your notebooks – • What did you notice when you were doing the grocery store scavenger hunt on Friday? Observations? Questions that came up? • Set up a chart in your notebooks to record everything you eat this week. Include a column for calories, and set up the columns but not the rows yet. • Homework:Set up an account at http://dailyburn.com or go to www.calorieking.com • Record your food for today and the calories. • Today’s Objective:Explain what a calorie is and how it relates to food, energy, and weight gain/loss.

3. Why Do We Eat? • Energy to survive • Vitamins & nutrients to stay healthy (strong bones, healthy immune systems, etc.) • Tastes good • Improves mood/attitude • Pleasure/fun • Social/cultural value

4. What is a CALORIE? • Write down what you think a calorie is. Calorie – a unit for measuring the amount of energy stored in chemical compounds • Measures energy stored in food • Measures energy stored in the molecules in your body (stored carbs, fats, etc.) Technical Definition: Kilogram calorie (aka kcal or Calorie) – the amount of energy needed to raise the temperature of 1 kilogram of water by 1oC.

5. Calories in Common Nutrients MACRONUTRIENTS contain Calories Vitamins, Minerals, and other Micronutrients have few/no calories • Carbohydrates(~4 kcal/gram) • Simple sugars • Starch • Fiber (fewer b/c can’t we can’t fully digest it) • Proteins(~4 kcal/gram) • Fats(~9 kcal/gram) Alcohol (not a macronutrient) contains ~7 kcal/gram) • Salt • Spices • Coffee • Tea • Caffeine • Vitamins/minerals (calcium, phosphorus, iron, vitamin A, vitamin C, B vitamins…) • Water

6. Calories in Common Foods • www.calorieking.com • http://dailyburn.com

7. EPICS Food: Tuesday, 12.7.09Calories, continued • Do Now:In your notebooks – • Based on the notes/discussion from yesterday, how would you define a Calorie in a way that other high school students could understand it? • What do you think happens to the energy in the food calories that we eat? • Homework:Continue recording food & Calorie intake online and in your notebook. (http://dailyburn.com or www.calorieking.com) • Today’s Objective:Explain what a calorie is and how it relates to food, energy, and weight gain/loss.

8. What happens to the calories(the energy) in the food we eat? Several possibilities: [This is a preview of the slides to come, so you don’t necessarily need to write this down] • Burn ‘em • Store ‘em • Poop ‘em out

9. What happens to the calories(the energy) in the food we eat? Several possibilities: • Food calories are “burned” to release energy as ATP and heat (through cell respiration) food + oxygen  CO2 + H2O + ATP energy + heat • This happens in all cells at low levels all the time b/c all cells need ATP to stay alive • Therefore, a certain number of calories are being burned all the time • Happens more in active cells, especially active muscle cells (need lots of ATP for movement) • Therefore, more physical activity = more calories burned

10. What happens to the calories(the energy) in the food we eat? Several possibilities: • Food calories are stored in the body (for later energy use). Two storage forms: • Glycogen – an energy-storing carbohydrate • Stored in liver and in muscle cells • Similar to starch • Easy to break down and use for quick energy release • Triglycerides - fats • Stored in fat cells (lipocytes/ adipocytes) under skin and around organs • Most stored energy is stored in this form

11. Calorie Storage in the Human Body: Glycogen (complex carb) Triglycerides (fat) [everywhere under skin and around organs]

12. What happens to the calories(the energy) in the food we eat? Several possibilities: • Some calories are un-digestible and therefore pass through w/o giving us energy • Some of the energy stored in fiber (cellulose) • The populations of bacteria in your intestines influence how many calories a person can extract from some foods • Different people = different bacteria = different #s of calories from the same food!

13. Health Effects Related to Calorie Intake • Too few Calories – Malnutrition/Starvation • Too many calories - Obesity

14. Malnutrition/Starvation(A brief overview) • Caused by lack of adequate calories consumed • The process: • Burn stored glycogen and stored fats for energy • When glycogen is used up, mostly burn fats for energy • When most fats are used up, burn proteins for energy • This is not ideal, because protein used to maintain skin, hair, muscle, immune system, etc. is broken down to provide energy

15. A Vietnamese man suffering from starvation during the Vietnam war. A Nigerian girl exhibiting the effects of severe hunger and malnutrition Pictures taken from Wikimedia Commons

16. Obesity(A brief overview) • Caused by an excess of Calories consumed (and/or not enough Calories burned) • Influenced by activity levels, genetics, diet, sleep… • Defined by an excessive amount of stored body fat • Also defined as having a BMI above 30 (above 40 = morbidly obese) • The process: Fat cells multiply, and each fat cell gets bigger

17. Obesity(A brief overview) • The results: • Mild symptoms: • Difficulty sleeping • Joint/back pain • Excessive sweating/feeling hot • Rashes/infections in skin folds • Daytime sleepiness • Feeling out of breath with minor exertions • Severe complications include: • Heart disease • High blood pressure • Osteoarthritis • Increased risk of cancer • Increased risk of type 2 diabetes • Stroke