I am What I Eat “I Am What I Eat”
Why do we need Food? Energy Muscle movement Body temp Measured in kJ (kilojoules) Eg an apple has 224 kJ of energy (224,000 Joules) Growth Material for cell growth Replacing old cells Keeping healthy To keep cells & organs functioning properly
Food Groups All food contains water –lettuce 93%, peanuts 5% Protein –Can’t be stored, eat regularly –Material for cell growth / repair –Used in muscle tissue Fats / Oils (Lipids) –2.5 times energy of carbs. –Eg marg, butter, fried food Vitamins & Minerals –Important in cell reactions –In: fruit, beans, nuts, meats Carbohydrates –Sugars: Provide fast energy Eg fruit, honey, lollies –Starch: provide Provide slow release energy Eg rice, potatoes –Cellulose Aka “fibre” Eg fruit, veges, cereals Note: Excess energy is stored as fat on the body.
Vitamin C (what’s the big deal?) An antioxidant Important in collagen synthesis –Scurvy...onset 1-6months after switching to Vit C free diet Important in numerous other processes Generally: enough vits and minerals in most western diets (excess excreted – berocca!, excess toxic?)
Nutritional Panels
List ingredients (largest to smallest) List allergens (food that cause allergic reactions, eg nuts) List food additives (chemicals/substances added to food to enhance flavour, taste appearance) Give serving size so: –You can compare to other foods –You know how big a reasonable portion is –You know how much nutrients a portion gives Show %RDI or how much of each food type the food contributes to your recommended daily intake Food additive list:
Double Down Nutritional Panel Questions 1.How big is one serve / portion? 2.How much energy from one serve? 3.How many double downs could you eat before you reach your daily energy of 9000kJ? 4. What percentage of fat? (look at total fat per 100g) 5. How many grams of sodium (salt)? 6. Which food types (fat, carbohydrates, proteins) are high? 7. Are double downs healthy to eat? Why, why not?
Fast Food Diet Task: Build up a poster of a one day diet of fast food that is “healthy” or “balanced” Challenges: Total energy MUST NOT EXCEED 9270kJ (average daily energy need for a 14 year old male) MUST contain lipids (fats or oils), vitamins and minerals, protein, carbohydrates (sugar, starch, fibre). Include a source of CALCIUM & IRON * less than 70g of fat ** les than 6g of salt
Food tests ol/controls.html es.html
Benedict’s Test Simple Sugars Add a few drops of Benedict’s solution (blue) to solution to be tested (5mL) Heat carefully Yellow / green / brick red colour change indicates simple sugars CLEAN UP!
Iodine Test Starch Add a few drops of iodine (yellow) to solution to be tested (5mL) Blue-black colour change indicates starch CLEAN UP!
Biuret Test Protein Put solution to be tested in a test tube (5mL) Add an equal volume of sodium hydroxide (NaOH) Add 1-2 drops of copper sulfate solution (CuSO 4 ) Purple colour indicates protein
Filter Paper Test Fat Rub sample onto filter paper. Label, do the same with water. Allow to dry Translucent (semi- see through) marks indicate fat
Ethanol Test Lipids Put 1mL of ethanol into a test tube. Add a few drops of oil or small piece of crushed up food. Shake, add 1mL of water. Cloudy colour indicates fat or oil Emulsion = Suspension of two liquid ingredients that do not dissolve into each other (eg oil & water)
What does Bile do? Do This: Mix a little oil + vinegar in a test tube. Observe. Add a small pinch of mustard, mix. Observe. Results Copy title then copy & complete below: 1.Oil and vinegar d_______ mix 2. The mustard emulsified the oil (this means it spread the o____ through the v_____) 3. Bile e_____ oil and fat in the s____ i_________. This helps d_________ by breaking lipids like f__ and o____ into smaller pieces.
What is a Balanced Diet? Contains all the food groups: –carbohydrates, lipids (fats & oils), protein, vitamins & minerals –in the right amounts Has the right amount of energy: –9,270 kJ or 9.3 MJ (for 14yr old male)
Consequences of an Unbalanced Diet FoodLowHigh Carbs Lipids Protein Vitamins & Minerals