NTR 301 1st Edition Lecture 9 Outline of Last Lecture I Pyramid vs MyPlate II Specifics of some food groups III Fresh Fruits and vegetables Are they better than canned or frozen Outline of Current Lecture I Agents that can lower the nutrient amount in food A Fresh vs canned and frozen foods II Problems with Assessing Dietary Intake III Assessing Nutritional Status Current Lecture Nutrients can be Destroyed The chemical attributes of the food is altered so they are no longer functioning Lost Not changed chemically but taken out of the food example Peeling washing Factors that can destroy food Oxygen heat natural and artificial lighting What determines how much nutrients are lost The longer a food is exposed to the above factors the greater the damage The higher the temperature the greater the damage The more water the greater depletion of nutrients More surface area exposed more destruction and loss Fresh fruits and veggies versus canned and frozen These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute Fresh Transported in refrigerated trucks to preserve nutrients Could be exposed to 24 hour light for more several days before purchase Kept at home for several days in light etc Pre cut increases surface area for exposure Factors that could lower nutrient amounts Oxygen light heat Frozen Picked at maximum maturity nutrients are also at maximum amounts Vegetables typically blanched to deactivate spoiling enzymes Can usually be stored for a year Doesn t kill microorganisms but keeps them from multiplying Factors that could lower nutrient amounts Smaller amounts of water and heat mainly veggies Canned Heated in high temperature for a short amount of time to kill microorganisms Kept in airtight container Factors that could lower nutrient amounts Short duration of high heat and some water some nutrients end up in the water Fresh is not ALWAYS best and nutrients are not all affected the same way or lost Cooking at home in order of best methods to preserve nutrients Microwaving Steaming Boiling Problems with Assessing Dietary Intake Self reporting what food is being consumed can be inaccurate because People tend to change the way they eat because they are more aware Embarrassment can cause people to lie about what they ve eaten This creates a faulty picture of typical intake which causes bias This is why dietary intake isn t always a good indicator of nutrient intake also nutrient intake should be measured over time and day to day changes are insignificant Bias Systematic distortion of a result that happens the same way every time Assessing Nutritional Status Biochemical Tests Assesses individual micronutrient levels in the body examples Blood testing for iron Urine Anthropometric Tests Macronutrient intake is measured in relation to the whole body and body composition Examples Weight and height for age growth charts for children Weight for height adults Body Composition Measured in fat versus lean tissue Examples Underwater weighing Fat is less dense than water Advantage Most accurate Disadvantage Must be weighed underwater not many people will go out of their way to get it done Skinfold Thickness Calipers measure fat around the body Advantage Easier to do than underwater weighing and easier to measure change over time Disadvantage Must have a well trained evaluator Also this only measures subcutaneous fat and not disease related fat Bioelectrical Impedance Electrical current is passed through the body to calculate water content based on resistance that is converted to lean tissue and fat by difference Advantage Can be done at home with no training Disadvantage Not accurate if an individual is under or over hydrated