Nutrition and Food Labels We often monitor our diets by scanning the information on the labels of the prepared foods we eat. We will examine our preconceived notions about food and diet.

Our food is primarily: Carbohydrates Fats Proteins Macronutrients – need large amounts (scale of grams, not milli or micrograms), provide calories (energy) and physical pieces within the body 45-65% of calories from carbs – essential for CNS, enables fat metabolism and prevents proteins from being used 15-35% from fats 10-35% from proteins

main source of “energy” Monomers, dimers and polymers Carbohydrates are: main source of “energy” Monomers, dimers and polymers -saccharides broken up into simple sugars (monomers) during digestion Begins in mouth, mainly in small intestine Takes longer to digest “complex” carbohydrates Polysaccharides 45-65% of calories are expected to come from carbs. Monosaccharides – glucose, fructose, galactose and ribose Disaccharides – lactose, sucrose, maltose Polysaccharides – starch (insoluble in water, main plant energy storage), glycogen (how we/animals store sugar for energy). Different because of branching and linkages. Alpha linkages in starch, alpha(1-4) in glycogen with (1-6) branches; Non-digestible versions, like cellulose are beta(1-4)  the importance of enzymes! **No essential carbohydrates, but essential fatty acids and proteins! So important we couldn’t evolve without that machinary!.

have the highest energy/unit mass saturated or unsaturated Fats: have the highest energy/unit mass saturated or unsaturated broken up into glycerol and fatty acids in the stomach and small intestines once broken up, can participate in cellular respiration also used for cell membranes, padding and insulation Energy dense (don’t need as much) – mostly used for energy, but we do have essential FAs 10-35% of calories from fats Digested mostly in small intestine – need bile because they are not soluble in water (generally) Saturated or unsaturated depends on double bonds (thus shape) Omega 6 FAs are converted to prostaglandins (inflammation and swelling)  good or bad? Is there a reason for pain? Omega 3 FAs, so famous, LESS inflammatory than Omega-6s (therefore considered anti-flammatory). Starting point for hormones that regulate inflammation, blood clotting and arterial wall contraction. Omega 3s found in fish, also vegetable oil, nuts (walnuts!), flax seeds, and leafy vegetables Trans fat are the same shape as saturated fats, but missing hydrogens and have double bonds. Bad because they increase plaque build up in arteries 00> heart disease. So. Are fats bad?

amino acids are then used to Proteins are: amino acid polymers broken up in stomach amino acids are then used to make new proteins build muscle and other connective tissue immune function machinery for all body functions contribute energy via glycolysis or the Krebs cycle Long chains of amino acids that fold up around themselves Unlike carbs, digested in stomach due to acid (pH 1.5-3) Any amino acids not used to make new proteins are stored as fat (only 4 calories per gram). Essential part of central dogma  all functions in the body are performed by proteins!

“Food Calories” calorie = the amount of energy needed to raise 1 gram of water by 1 oC a food Calorie = 1000 calories

Biomolecule Calories Carbohydrate 4.4 calories/gm Fat 9.0 calories/gm Protein Rounded to 4 for carbs and protein.

Daily Requirements 1,600 Calories a day for children, inactive women, and older adults. 2,200 Calories a day for moderately active women, inactive men, and teenage girls. 2,800 Calories a day for teenage boys, active women, and active men. 2,200 to 2,800 Calories a day for pregnant and breastfeeding women. This is all a ranging scale. The only true way to tell the correct number of calories someone needs is to consume the same amount every day and watch to see if their weight changes. From a nutrition standpoint, consuming more or less in a given day isn’t important. Generally weekly consumption amounts are important when considering whether someone is deficient.

ENERGY (Kcal per ½ hour) ACTIVITY ENERGY (Kcal per ½ hour) Basketball Cleaning Cooking, active Cycling, moderate Gardening Jogging Marathon running Sitting Sleeping Studying Walking Watching Television 400 95 110 150 150 300 495 45 30 50 160 45 Generally about 1 mile of running/walking translates to 100 calories burned. In regards to sittings vs watching tv… studies have been done that show essentially no brain activity while people are watching tv. Some more stats: Weight lifting: ~220 Football: ~270 Ultimate: ~240 Field Hockey: ~240 Rock Climbing: ~340 Soccer: Between 200-300 (casual to competitive) Table Tennis: ~100 Squash: ~370

A Typical Food Label Required to include all of these aspects: Serving size, servings per container Amount per serving of: calories, calories from fat, fat (saturate, trans), cholesterol, sodium, potassium, carbs (fiber and sugars), protein. Often includes mono and poly unsaturated fats and total in package (like a bag of chips or bottle of soda that has 2.5 servings).