10/1/2021 WHAT IS NUTRITION? The study of - Food choices - Use of food-derived molecules in the body - How food influences our health What are nutrients? - Chemicals in foods - Used for energy, growth, maintenance, and repair of our tissues Essential nutrients: - scientific biological functions have been identified - Our bodies cannot make enough of to meet our biological needs Non-essential nutrients: - Body can produce sufficient amounts Classes of nutrients: - Carbohydrates - Proteins - Fats (lipids) - Vitamins - Minerals - Water Two categories of nutrients: 1. Macronutrients - Carbohydrates - Proteins - Lipids - Water ● Nutrients required in relatively large amounts ● Carbohydrates, proteins, and lipids supply energy ● Water doesn’t provide energy 2. Micronutrients - Vitamins - Minerals ● Nutrients required in smaller amounts ● Do not supply energy, but needed to process macronutrient fuels Energy from nutrients: - Measured in kilocalories (kcal) ● Amount of energy required to raise the temperature of 1kg of water by 1℃ On food labels, “calorie” actually refers to kilocalories Carbohydrates, proteins, fats, and alcohol provide energy MACRONUTRIENTS Carbohydrates - Energy content: 4 kcal/g - Structural function: abundant in skin, cartilage, ligaments, and other joint tissue, sugars are a component of DNA and RNA - Regulatory function: critical source of energy for brain and red blood cells, helps regulate bowel function Lipids: - Energy content: 9 kcal/g - Structural function: components of the cell membrane, fat deposits shape our body and provide insulation and protection - Regulatory function: required for synthesis of hormones and other compounds that regulate many body processes Proteins: - Energy content: 4 kcal/g - Structural function: Major structural component of every cell and tissue in our body - Regulatory function: Regulates fluid balance and facilitates chemical reactions Water: - Energy content: 0 - Structural function: Fills and surrounds every cell - Regulatory function: Controls body temperature and is involved in many chemical reactions *Alcohol is not a nutrient (it is a toxin) but it supplies energy 7 kcal/g Dietary patterns: - Represent the totality of what individuals habitually eat and drink, and the parts of the pattern act synergistically to affect health ● The dietary pattern may better predict overall health status and disease risk than individual foods or nutrients WHY IS NUTRITION IMPORTANT?: - To reduce the incidence of nutrition-related diseases ● Highly processed foods associated with dietary patterns that increase risk of chronic diseases ● Diets high in fruits and vegetables and overall less processed foods are associated w/ reduced risks - To promote optimal health and wellness WHY IS ADEQUATE NUTRITION INTAKE IMPORTANT? - To reduce the incidence of nutrition-related diseases 10/4/2021 Dietary Guidelines for Americans (DGA): - Provide science-based advice on what to eat and drink to promote health, reduce risk of chronic disease, and meet nutrient needs - Designed to help all individuals consume a healthy, nutritionally adequate diet - Rewritten every 5 years Dietary patterns: the totality of what individuals habitually eat and drink Results of nutritional deficiencies: - Beri Beri (Jakarta, Indonesia) ● Christiaan Eijkman, 1895 went to study Beri Beri, convinced it was an infectious disease. Used sick chickens and initially set up his study next to a hospital. In the - - - process of moving his study, chickens ' health got better. Occurred because the chickens were fed brown unpolished rice. - Thiamin’s Discovery (Eijkman 1895) ● Elkjman kept 11 chickens on a diet for 5 weeks ● After five weeks, sick chickens who were fed unpolished rice recovered. Healthy chickens who were fed polished rice became sick. Injected chickens fed unpolished rice remained healthy. Control chickens fed unpolished rice remained healthy. Pellagra (Goldberger, 1915) *Major problem in Southeast U.S. ● Characterized by lesions on skin, dermatitis, diarrhea, dementia (neurocognitive changes) which can lead to depression, hallucinations, etc, death ● Mainly affected workforce ● U.S. sent Joseph Goldberger (researcher of infectious diseases), observed kids in orphanages and prisons. Found that little kids and prisoners got sick but not the caregivers/guards. Observed diets. Fed them balanced diets, which cured them; this discovery was dismissed by those who were convinced this was an infectious disease. - Held filth parties, where they purposely injected themselves with pellagra. But none of them caught pellagra, due to their healthy diets. - Conclusion: lack of niacin was the issue Vitamin discoveries led to dietary recommendations: ● 1941: U.S. Food and Nutrition Board established - 1st Recommended Dietary Allowances (RDAs) published 1943 - Purpose: to prevent nutrient deficiency ● RDAs revised 9 times, last in 1989 1994: Dietary Reference Intake Recommendations (DRIs): ● Joint effort by the FNB and Health Canada initiated to establish Dietary Reference Intake between 1997-2011 - New areas: ● Expand on the traditional RDA values ● Set standards for nutrients that don’t have RDA values ● Dietary standards for healthy people only ● For preventing deficiency diseases and reducing chronic diseases - EAR: Average daily intake level of a nutrient that will meet the needs of half of the healthy person in a particular category RDA: Average daily intake level required to meet the needs of 97-98% of healthy people in a particular category AI: Recommended average daily intake level for a nutrient; used when RDA isn’t yet established (such as in infants); biotin UL: Highest average daily intake level likely to pose no risk of adverse health effects to most people - - EER: Average dietary energy intake (kcal) to maintain energy balance in a healthy adult Using DRI Values to Assess Nutritional Status: - - AMDR: portion of energy intake that should come from each macronutrient ● Distribution of energy among macronutrients ● Malnutrition: too much or too little of a particular nutrient or energy Undernutrition: too little energy or too few nutrients Overnutrition: too much energy or too much of a given nutrient 10/6/2021: Choosing Foods Wisely A healthful diet provides the proper combination of energy and nutrients. A healthful diet is - Adequate ● Enough energy ● Enough nutrients ● Enough fiber and fluids ● To support health and wellness - Moderate ● Pay attention to what you’re eating ● Be aware of portion sizes - Balanced ● Not overconsuming any one food ● Eat foods from major food groups - Varied ● Not eating the “same old thing” ● Choose a number of different foods within any given food group ● Ensures the diet contains sufficient nutrients - Nutrient dense - Nutrient density: the ratio of nutrients to energy - ● Weight of nutrients/calories ● Usually want it to be high Energy density: the ratio of energy to weight or volume ● Calories/weight or volume of food ● Sometimes want it to be low, sometimes high ● kcals/weight of volume of food ● Directly associated with fat content ● Inversely associated with water and fiber content - Processing tends to reduce nutrient density - MyPlate can be used to plan a healthful diet ● Based on the Dietary Guidelines for americans and the Dietary Reference Intakes ● ● 2020 Dietary Guidelines for Americans 1. Follow a healthy dietary pattern at every life stage ● Established Healthy Eating Index Scores, 100 = healthiest 2. Customize and enjoy nutrient-dense food 3. ? 4. Limit food and beverages higher in added sugars, saturated fat, sodium, and limit alcoholic beverages Mandatory on a food label: - Product name - Manufacturer’s name and address - Uniform serving size - Amount in package - Ingredients in descending order by weight - Potential allergens - Nutrient components - Percent daily value
