Chapter 1 What Is Nutrition?

Objectives for Chapter 1 Discuss the factors that influence food choice. Define the term nutrition. Describe how nutrition affects your health. Name and explain the six categories of nutrients found in food and in the body. Differentiate between the three energy nutrients: carbohydrate, protein, and fat. Calculate the calorie content of a food based on the grams of carbohydrate, protein, and fat. Understand the important roles that vitamins, minerals, and water play in your diet. Understand the scientific method that is involved in nutrition research. Discuss the current nutritional state of the American diet.

What Drives Our Food Choices? We need to eat and drink to obtain: Nutrients: chemical compounds in foods to provide: fuel for energy (measured in kilocalories) growth maintenance Regulate body processes

Copyright © Cengage Learning. All rights reserved Energy Capacity to do work or to produce heat. The total energy content of the universe is constant. PHET:Energy forms and changes PHET:Energy Skate Park(adv) Different types of energy: https://www.youtube.com/watch?v=k4b3oxO0WqE Charging up vs eating up: https://www.youtube.com/watch?v=TnNixMosUIo Copyright © Cengage Learning. All rights reserved

Grouping our food. http://www.phytochemicals.info/phytochemicals.php There are Six classes: Carbohydrates Fats Protein Vitamins Minerals Water Phytochemicals: non-nutrient compounds that contribute to health and may play a role in fighting chronic diseases. They are found in fruits, vegetables, grains, beans, and other plants. http://www.phytochemicals.info/phytochemicals.php

What Are the Essential Nutrients and Why Do You Need Them? The six classes of nutrients are all essential in the diet Macronutrients: energy-yielding nutrients needed in higher amounts Carbohydrates (when broken down provide glucose) lipids (fats) proteins Micronutrients: needed in smaller amounts Vitamins and minerals Copious amounts of water needed daily Alcohol provides calories but is not an essential nutrient Taste Buds: https://www.youtube.com/watch?v=j7GibFhuBmE

What Drives Our Food Choices? We choose foods for many other reasons beyond the basic need to obtain nutrients: Taste and culture Social reasons and trends Cost, time, and convenience Habits and emotions See Do Outside Factors Influence Your food choices? P. 6

What Is Nutrition and Why Is Good Nutrition So Important? Nutrition: a science that studies how nutrients and compounds in foods nourish and affect body functions and health Chronic deficiencies, excesses, and imbalances of nutrients can affect health, both short-term and long-term Good nutrition plays a role in reducing the risk of many chronic diseases and conditions, including heart disease, cancer, stroke, diabetes, osteoporosis, high blood pressure, and obesity

Table 1.1

Earth’s Chemical Composition

Nutrients in Foods and in the Body Figure 1.2

Nutrients and Their Functions Figure 1.3

What Are the Essential Nutrients and Why Do You Need Them? Carbohydrates, fats, and proteins Provide energy Carbohydrates and protein provide 4 kcal/gram Fats provide 9 kcal/gram = 9 Cal/g Are organic compounds (contain carbon atoms) Also contain hydrogen and oxygen atoms Proteins also contain nitrogen atoms (unlike carbohydrates and fats)

What Are the Essential Nutrients and Why Do You Need Them? Carbohydrates supply glucose, the major energy source. Should be the majority of your diet Fats (lipids) are another major fuel source and also: Cushion organs Insulate body to maintain body temperature Proteins provide energy but are better suited for: Growth and maintenance of muscle, tissues, organs Making hormones, enzymes, healthy immune system Transporting other nutrients

What Are the Essential Nutrients and Why Do You Need Them? Vitamins and minerals are essential for metabolism but are calorie free! Many assist enzymes (enzymes speed up reactions but are not part of the reaction) Example: B vitamins are coenzymes in carbohydrate and fat metabolism Vitamins are organic compounds Minerals are inorganic substances

Vitamins vs Minerals Vitamins ("vita" = life and "amine" = containing nitrogen) are organic (containing carbon, which is an element found in all living things) Each of these vitamins have unique roles and functions in our bodies. Example, vitamin A promotes eyesight and vitamin K helps blood to clot. Fat Soluble: Vitamins A, D, E, K Water Soluble: Folate, Niacin, B6(Pyridoxine), B12, B2(Riboflavin), C, B1(Thiamin), Folic Acid, Pantothenic Acid

Vitamins vs Minerals Minerals are pure inorganic elements like calcium, potassium, iron etc. Play vital roles in the body, such as calcium in osteoporosis prevention and iron in (iron-deficiency) anemia prevention. Other minerals, such as lead, are harmful.

What Are the Essential Nutrients and Why Do You Need Them? Water is vital for many processes in your body Part of fluid medium inside and outside of cells Helps chemical reactions, such as those involved in energy production Key role in transporting nutrients and oxygen to cells and removing waste products Lubricant for joints, eyes, mouth, intestinal tract Protective cushion for organs Temperature control

How Should You Get These Important Nutrients? The best way to meet your nutrient needs is with a well-balanced diet Composed of a variety of foods, providing: Essential nutrients from all six classes Fiber and phytochemicals Whole grains, fruits, and vegetables are rich sources

How Should You Get These Important Nutrients? You can meet some nutrient needs with a supplement When nutrient needs are higher Example: Pregnant women need an iron supplement to meet increased needs When diet restrictions exist Example: Lactose-intolerant individuals (difficulty digesting milk products) may choose a calcium supplement to help meet needs Well-balanced diet and supplements are not mutually exclusive; they can be partnered for good health

Calorie Count: Eat by the Numbers Discussion: Can people’s diet change with information? http://abcnews.go.com/WNT/video/counting-calories-diet-american-eat-food-13283562

Calorie Count: Eat by the Numbers Discussion Questions Would knowing the amount of calories effect your food choices? How far should government go in helping you make healthy choices? What if addiction to foods is as addictive as drugs?

How Does the Average American Diet Stack Up? Average American diet is high in: Sodium Saturated fat Calories Average American diet is low in: Vitamin E Calcium Fiber

How Does the Average American Diet Stack Up? Incidence of overweight and obesity is on the rise 65 percent of American adults and 15 percent of children (ages 6 to 19) are overweight Take in more calories than needed Burn fewer calories due to sedentary lifestyles Resulting in increased rate of type 2 diabetes (especially children), heart disease, cancer, and stroke

How Does the Average American Diet Stack Up? Figure 1.4

What’s the Real Deal When It Comes to Nutrition Research and Advice? Newspaper headlines and television news items report results of a single, recent research study Advice from authoritative health and nutrition organizations is based on: Consensus: the opinion of group of experts based on collection of information

Evaluating Media Headlines with a Critical Eye Before making dietary and lifestyle changes based on media reports, read with a critical eye and ask: Was the research finding published in a peer-reviewed journal? Was the study done using animals or humans? Do the study participants resemble me? Is this the first time I’ve heard about this? Wait until research findings are confirmed and consensus reached by reputable health organizations before making changes

The scientific Method https://www.ted.com/talks/ben_goldacre_battling_bad_science#t-698018

Steps of the Scientific Method Figure 1.5

A Hypothesis Can Lead to a Scientific Consensus Figure 1.6

Research Studies and Experiments Confirm Hypotheses Observational Research: involves looking at factors in two or more groups of subjects to see if there is a relationship to certain health outcomes Epidemiological research: study of populations of people Example: Relationship of sun exposure and incidence of rickets in Norway compared with Australia May be due to other unidentified diet or lifestyle factors

Research Studies and Experiments Confirm Hypotheses Experimental Research: involves at least two groups of subjects Experimental group: given a specific treatment Control group: given a placebo (“sugar pill”) Double-blind placebo-controlled experiment is “gold standard” Neither scientists nor subjects know which group is receiving which treatment All variables held the same and controlled for both groups

Controlled Experiments Figure 1.7

Describe an experiment you would design to test the following hypothesis: Vitamin C supplements cure colds . Find a large sample size with colds Divide them randomly into 2 groups One gets vitamin C, the other gets a placebo Double Blind! Experiment is observed Compare groups

What Is Nutritional Genomics? Genes determine your inherited, specific traits Made of DNA, which contains the genetic instructions for making proteins that direct activities in the body Nutritional Genomics: study of how specific food components affect gene expression in your cells and thereby your health Example: may help determine the specific dietary combination of fats needed to lower your risk of heart disease based on your unique genetic make-up