Nutrition Guidelines: Applying the Science of Nutrition PDF

Nutrition Guidelines: Applying the Science of Nutrition 1 Learning Objectives 1. Differentiate between the food-based approach and nutrient-based approach used in nutrition recommendations 2. Compare and contrast food guide...

Nutrition Guidelines: Applying the Science of Nutrition 1 Learning Objectives 1. Differentiate between the food-based approach and nutrient-based approach used in nutrition recommendations 2. Compare and contrast food guides from Canada and other countries 3. Discuss the Dietary Reference Intakes (DRI): EAR & RDA, AI, UL, AMDR 4. Define estimated energy requirement (EER) and describe EER it is related to energy balance 2 Dietary reference intakes: EAR & RDA, EAR cutpoint, AI, UL https://www.canada.ca/en/health- canada/services/food-nutrition/healthy- eating/dietary-reference- intakes/tables.html#abb 3 2.1 Nutrition Recommendations for the Canadian Diet Nutrient-based approach Food-based approach How much of a nutrient is Dietary pattern required to maintain health? Types and amounts of foods to maintain health Recommendations are regularly updated. 4 https://www.canada.ca/en/health-canada/services/food-nutrition/healthy-eating/dietary-reference- intakes/development-dietary-reference-intakes.html 5  2.1Nutrition Recommendations for the Canadian Diet History Today First recommendations in Canada Dietary Reference Intake (DRIs) 1939, 1943 Recommended Nutrient Intakes Determined by the Institute of (RNI) Medicine (IOM) by Canadian and American scientists beginning in the 1990’s and continuing today Nutrient-based approach 6 Canada’s Official Food Rules 1942: Fig 2.2 Food-based approach 7 https://www.canada.ca/en/health-canada/services/food-nutrition/healthy-eating/dietary-reference- intakes/development-dietary-reference-intakes.html 8 Nutrition recommendations from all around the world Food-based approach  South Africa Ghana India Food-based approach  Mexico Saudi Arabia United Kingdom Food-based approach Food-based approach 13 https://www.fao.org/nutrition/education/food-dietary-guidelines/regions/asia-pacific/en/ 14 2.2 Dietary Reference Intakes (DRIs) For planning and assessing diets of healthy individuals Values for different life stages/ males or females Infants Children Listed in DRI tables Teens You will use the DRI tables for part of the Nutrition Numbers Quiz Young, middle, older adults Pregnancy/lactation 15  2.2 DIETARY REFERENCE INTAKES (DRI) ENERGY MACRONUTRIENTS OTHER NUTRIENTS Estimated Acceptable Energy Macronutrient Chronic Disease Risk requirement Distribution Reduction Intake (EER) Range (CDRR) (AMDR) Adequate intake (AI) Tolerable Upper Intake Level (UL) Estimated Average requirement (EAR) Recommended Dietary Allowance (RDA) Know what abbreviations stand for 16 Statistics 2 Median intake 1 Normal distribution Frequency: 3 Standard Number of deviation individuals Variance Nutrient intake (mg) 17 Statistics 1 What is the same ? 2 What is different? 18 Statistics Shaded area under the curve →probabilityor proportion of adequate or inadequate nutrient intake 50% of the curve is shaded → 50% probability or proportion of adequate or inadequate nutrient intake 19 2.2 Dietary Reference Intakes Estimated Average Requirement (EAR) Definition Nutrient intake that meets the requirement of 50% of individuals in a group (i.e. sex; age) How is it used To estimate the probability that an individual’s usual intake is meeting his/her requirement To estimate what proportion of a group is meeting their requirements 20 2.2 Dietary Reference Intakes: Estimated average requirement (EAR) How is it determined? Determine a biochemical criterion that allows you to determine the intake at which an individual’s requirement is being met Determine the requirement distribution from a sample of the population 21 2.2 Dietary Reference Intakes: Establishing EARs CONSIDER: Hypothetical Vitamin X Physiological criterion: Vitamin X requirement is met when the level of Vitamin X in serum reaches saturation IMPORTANT: not universal criterion for all nutrients Conduct a depletion-repletion experiment on a population of healthy adults 22 2.2 Dietary Reference Intakes: Establishing EARs: Hypothetical vitamin X Depletion Depletion Next step? Fed a vitamin X-free diet Levels of vitamin X in blood are tracked Eventually levels decline until no vitamin X is detected (i.e. the individual is deficient) Fig 2.3 23  2.2 Dietary Reference Intakes: Hypothetical vitamin X: Next step? Repletion Repletion Begin refeeding vitamin X What happens? Blood levels of vitamin X begin to rise Eventually each individual reaches an intake at which there is no corresponding rise in blood levels i.e. blood is saturated with vitamin X Fig 2.3 That Vitamin X intake is the individual’s vitamin X requirement Will the requirement be the same for each individual? 24 2.2 Dietary Reference Intakes: Requirement Distribution for Vitamin X (39 subjects) Normal distribution Number of EAR = 100 mg individuals 50% of subjects meet their requirements 60 70 80 90 100 110 120 130 140 See Fig 2.4 Vitamin X Intake (mg) 25 2.2 Dietary Reference Intakes: To understand how requirement distributions are used, it is important to distinguish between REQUIREMENT and INTAKE Nutrient Requirement Nutrient Intake Experimentally- determined Amount of nutrient consumed requirement for a nutrient Determined by the composition Amount required to maintain of the diet health 26  2.2 Dietary Reference Intakes EAR (Estimated average requirement) EAR represents the average daily From the Vitamin X nutrient intake that requirement meets the distribution the requirements of EAR can be half the healthy determined individuals in a given group. If an individual’s nutrient intake is equal to the EAR then there is a 50:50 Fig 2.4 chance the individual is meeting his/her requirement *that meets the requirements of Nutrient Intake* (mg) individuals in the experimental group 27  2.2 Dietary Reference Intakes: Determining the probability of meeting requirements from the requirement distribution of a nutrient Usual intake of nutrient What is the probability that A is meeting their requirement? Fig 2.5 Assuming the grey area represents about 12% of the total area under the curve, than the probability that A is meeting their requirement is 12%.. Nutrient Intake (mg) 28 Determining the probability of meeting requirements from the requirement distribution of a nutrient What is the probability that 80% B is meeting their requirement? Gray area represents 80% of the total area under the curve. Fig 2.5 Nutrient Intake (mg) 29 2.2 Dietary Reference Intakes: RDA = Recommended Dietary Allowance: intake that ensures a 98% probability of meeting your requirement RDA = EAR + 2 How is the RDA used? Standard Deviations As a goal for an individual’s usual intake, because it is almost certainly RDA adequate Fig 2.4 30 2.2 Dietary Reference Intakes Recommended Dietary Allowance EAR RDA: meets the requirements of 98% of individuals : 140 mg Fig 2.4 31  EAR cutpoint methods Up to this point, we have looked at individuals and the probability that they are meeting their requirements based on the position intake on the requirement distribution Now we are going to look at populations and the proportion of a population meeting its requirements based on an intake distribution. This requires a new methodology → 32  2.2 Dietary Reference Intakes: Using the EAR cut point method to Determine the Prevalence of Adequate Intake within a Group To estimate what proportion of a group is meeting their requirements EAR cut point method Intake distribution Results of a survey of nutrient intakes 33 2.2 Dietary Reference Intakes: EAR cutpoint method Intake distribution EAR cutpoint method Median Intake Proportion of the population whose intake is less than the EAR Proportion of the = population that is NOT meeting its requirement Fig 2.6 & 2.7 34 2.2 Dietary Reference Intakes: EAR cut point method Fig 2.8 35 QUESTION: If two populations have the same the median intake does that mean that the proportion of the population is meeting its requirement is the same? ANSWER: Not necessarily… Consider these two intake distributions. How well a population is doing with respect to nutrient intake depends on both the median intake and the standard deviation of the intake distribution 36  2.2 Dietary Reference Intakes: How is the EAR cut point method used: Health Canada: Considers a population to have an adequate intake if the proportion of the population whose intake is below the EAR is 10% or less Remember this range Canadian Community Health Survey-Nutrition: Measured nutrient intake and used the EAR cut point method to determine the adequacy of nutrient intake 37  2.2 Dietary Reference Intakes: Adequate Intake Insufficient data to calculate an EAR More research is needed Usually based on an estimate of average nutrient intake by a healthy population Example: Recommendations for calcium intake for young infants 0-6 months of age = 200mg Adequate intake of 200 mg the average calcium intakes of exclusively breast-fed infants 38 2.2 Dietary Reference Intakes Adequate Intake If your intake > AI, then intake OK AI is good personal target If intake expended for metabolism & physical activity Positive energy balance Energy content Energy content Weight loss i.e. (kcal) of food consumed < expended for metabolism & physical activity Negative energy balance 45  2.2 Dietary Reference Intakes: Estimated energy requirements (EER) Equations (determined by experiment) are used to estimate the average energy needs of adults Men: EER = 662 – (9.53 x age [y]) + PA x See also (15.91 x weight [kg] + 539 x height [m]) section 7.3: Estimating Energy Needs Women: EER = 354 – (6.91 x age [y]) + PA x pg 274 (9.36 x weight [kg] + 726 x height [m]) PA (physical activity term) = 1.00 (sedentary) → 1.48 (very active) Don’t memorize equations, but know the variables involved 46 2.2 Dietary Reference Intakes: Definitions of activity levels SEDENTARY: LOW ACTIVE: Activities of daily Walking 30 minutes living; less than 30 at 6.5 km per hour min of intentional every day exercise/day + 135 to165 kcal ACTIVE: VERY ACTIVE: Walking 1 hour 45 Walking 4 hours 15 minutes at 6.5 km per minutes at 6.5 km per hour every day hour every day + 470 to 580 kcal + 1145 to 1405 kcal 47 2.2 Dietary Reference Intakes: EER (estimated energy requirement) and age Female: Female: Female: 5’5” 5’5” 5’5” 125 lb 125 lb 125 lb 20yrs 50yrs 80yrs Sedentary Sedentary Sedentary BMI 21 BMI 21 BMI 21 1950 kcal ? kcal ? kcal 1750 kcal 1550 kcal 48 2.2 Dietary Reference Intakes EER (estimated energy requirement) and sex Female: Male: Male: 5’5” 5’5” 5’10” 125 lb 125 lb 150 lb 20yrs 20yrs 20yrs Sedentary Sedentary Sedentary BMI 21 BMI 21 BMI 21 1950 kcal ????kcal ???? kcal 2250 kcal 2500 kcal 49 2.2 Dietary Reference Intakes: EER (estimated energy requirement) and body size Female: Female: 5’5” 5’5” 125 lb 150 lb 20yrs 20yrs Sedentary Sedentary BMI 21 BMI 25 1950 kcal ???? kcal 2250 kcal 50 Energy balance Consider what happens in positive energy balance. 51  2.2 DIETARY REFERENCE INTAKES (DRI) ENERGY MACRONUTRIENTS OTHER NUTRIENTS Estimated Acceptable Energy Macronutrient Chronic Disease Risk requirement Distribution Reduction Intake (EER) Range Adequate intake (CDRR) (AMDR) (AI) Tolerable Upper Intake Level Estimated Average requirement (EAR) (UL) Recommended Dietary Allowance (RDA) Know what abbreviations stand for 52 2.2 Dietary Reference Intakes DRIs for macronutrients = AMDR Acceptable Macronutrient Distribution Ranges UNDESIRABLE FATS: Expressed as % of total kcalories consumed SATURATED FAT: Carbohydrates: 45-65% As low as possible: Fat: 20-35%