Chapter 1 The Science and Scope of Nutrition

“You are what you eat.” Dutch children born during WWII ◦ If mother starved during beginning of pregnancy, children were more likely to be obese ◦ If mother starved during end of pregnancy, children were less likely to be obese “You are what your mother eats.”

Nutrition is… Why we eat What we eat How the foods we eat are used in our bodies How the foods we eat effect health and disease risk

What is a nutrient? A chemical substance that is essential for body functions ◦ Some nutrients are produced by the body, but essential nutrients must be obtained from the diet The amount and variety of nutrients in foods can either ◦ Promote health ◦ Increase risk of disease

Introducing…The six classes of nutrients! Carbohydrates Proteins Fats Vitamins Minerals Water Macronutrients Micronutrients

Another important part of the diet… Phytochemicals (also called phytonutrients) ◦ Chemicals found in plants that are beneficial for human health ◦ Give plants key properties such as color, aroma, flavor ◦ Thousands of different phytochemicals have been identified in foods

What is a calorie? A calorie is a measurement of energy Energy is the capacity to do work Carbohydrates, proteins and fats in food and beverages are broken down and used to create energy in the body….so carbs, proteins and fats contain calories

How many calories do nutrients contain? Carbohydrates: 4 calories per gram of food (4 kcal/g) Protein: 4 calories per gram of food (4 kcal/g) Fats: 9 calories per gram of food (9 kcal/g) Water, vitamins & minerals: 0 calories

Is alcohol a nutrient? No! It is a toxin Contains 7 calories per gram (7 kcal/g)

How do I know if I am getting enough of the nutrients? duo duo Dietary Reference Intake : Set of nutrition guidelines from the Institute of Medicine Amount of nutrients to intake to optimize health ◦ Prevent deficiency diseases ◦ Prevent toxicity diseases ◦ Prevent chronic diseases

The DRIs, continued RDA: Recommended Dietary Allowance AI: Adequate IntakeUL: Tolerable Upper Intake Level Nutrient intake goals for vitamins and minerals Highest amount of a vitamin or mineral that can be consumed safely (without toxicity symptoms) Nutrient recommendations vary by age and gender Nutrient limits vary by age and gender The numeric value for this recommendation is well- researched The numeric value for this recommendation is not well- researched The numeric value for this recommendation is well- researched Dietary Goal: Achieve 100% RDADietary Goal: Achieve 100% AIDietary Goal: DO NOT EXCEED the UL Exceeding 100% of the RDA does not make you healthier and may make you less healthy Exceeding 100% of the AI does not make you healthier Exceeding the UL could cause toxicity symptoms and, if untreated, may lead to death Tips to remember RDA: research is “Rock Solid” Tips to remember AI: research is evolving and could change Indiana JonesPool failUpper Limits!

Dietary Reference Intakes, continued… Acceptable Macronutrient Distribution Range (AMDR) Healthy range of intakes for carbohydrates, protein and fat ◦ Carbohydrates – 45-65% of total calories ◦ Protein – 10-35% of total calories ◦ Fat – 20-35% of total calories

Malnutrition A state of inadequate or unbalanced nutrition ◦ Undernutrition ◦ Overnutrition Both undernutrition and overnutrition may lead to chronic disease

The Scientific Method YAY!!!

Research Terminology Scientific Method Observation Hypothesis Experiment Research results or outcomes Peer-Reviewed Publication Scientific Theory Randomized Controlled Trial Experimental / treatment group Control group Placebo Placebo effect Epidemiologic Study Cause-and-effect relationship Correlational evidence Experimental model system