Nutrition

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Nutrition

• Chapter 15a

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All the chemical reactions in a persons body
constitute that persons metabolism

• Anabolic processes use energy to assemble cells
  tissues

• Catabolic processes break down nutrients to
  obtain energy raw materials

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The calorie is a measure of the amount of energy
in food

• How calories can be measured

• The calorie is the metric unit of energy, the
  amount of energy necessary to raise the
  temperature of 1 mL of water by 1oC
• Though they are still called calories, food
  calories, or Calories, are actually kilocalories,
  equal to 1000 regular calories

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1. All living things are composed of 4 common
macromolecules

• Nucleic Acids
• Proteins
• Carbohydrates
• Lipids
• DNA is a nucleic acid

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Nucleic acids and Proteins

• Proteins, made of amino acids

• Nucleic acids- DNA

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Carbohydrates and Lipids

• Carbohydrates- glucose fructose sucrose

• Lipids- a fat molecule made of glycerol and 3
  fatty acids

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Vitamins and Minerals

• There are 13 vitamins, and various minerals which
  the body must obtain through diet
• Vitamins and minerals often function as cofactors
  in enzymes
• Because cofactors are recycled, vitamins are
  required in minute quantities

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Human metabolism is diverse but limited

• Though the body can manufacture many of its own
  necessary parts, essential nutrients cannot be
  manufactured and must be obtained through diet
• Essential amino acids are required to make all
  proteins
• Essential fatty acids are required for cell
  signaling

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Nutrients

• Food provides
• Fuel for cellular activities
• Metabolic regulators
• Building blocks for
• Cell division
• Maintenance
• Repair

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We also need water

• Water is necessary for
• Proper cellular environments
• Certain cellular reactions

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Nutrients

• A nutrient is a substance in food that
• Provides energy
• Plays a structural or functional role to promote
  normal growth, maintenance, or repair

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Lipids
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Lipids

• Lipids
• Fats
• Oils
• Cholesterol
• 95 of the lipids found in food are triglycerides
  
• Consist of a molecules made from three fatty
  acids attached to a molecule of glycerol

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Lipids

• Fat
• A ready source of energy
• Insulation and a cushion for vital organs
• Components of the cell membrane
• Construction of myelin sheaths
• Absorption of fat-soluble vitamins

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Lipids

• Fatty acids differ in their degree of saturation
• Saturated fats
• Solid at room temperature
• Most come from animal sources
• Unsaturated fats
• Liquid at room temperature
• Come from plant sources

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Lipids

• A high-fat diet is associated with
• Obesity
• High blood pressure
• Atherosclerosis
• Increased risk of diabetes
• Certain cancers
• E.g., colon, prostate, lung

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Cholesterol

• Cholesterol
• The structural basis for the steroid hormones
• Low-density lipoproteins (LDLs)
• Bad
• They deposit cholesterol in the artery walls
• High-density lipoproteins (HDLs)
• Good
• They help the body to eliminate cholesterol

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Fats in the diet

• Only 20 to 30 of the calories in the diet should
  come from fats
• Most of those should be monounsaturated and
  polyunsaturated fats

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Carbohydrates
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Carbohydrates

• Carbohydrates
• Provide fuel for our bodies
• Found in our diet as sugars, starches, and fiber

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Carbohydrates

• Dietary fiber
• A carbohydrate in plant foods that humans cannot
  digest
• Good for the heart and blood vessels
• It lowers LDLs but does not lower the beneficial
  HDLs

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Carbohydrates

• 45 to 65 of the calories in our diet should come
  from carbohydrates, including both
• Simple carbohydrates
• Sugars
• Complex carbohydrates
• Starches and fiber

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Figure 15a.3
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Carbohydrates

• The glycemic response
• A measure of how quickly a serving of food is
  converted to blood sugar
• The glycemic index
• A numerical ranking of carbohydrates based on
  their glycemic response
• Foods with a low glycemic index help to reduce
  the risk of heart disease and diabetes

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Proteins
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Proteins

• Proteins
• The structural components of every cell
• Regulate body processes
• Are antibodies
• Can be used for energy

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Proteins

• Proteins
• Chains of amino acids that are digested and
  delivered to the cells
• Human proteins contain 20 different kinds of
  amino acids
• The human body can synthesize 11 of the amino
  acids
• The remaining 9 must be supplied by the diet
• Essential amino acids

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Proteins

• Complete dietary proteins
• Contain all 9 of the essential amino acids that
  your body cannot synthesize
• Incomplete proteins
• Lack one or more of the essential amino acids

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Proteins

• Complementary proteins
• Combinations of proteins that together supply
  enough of all the essential amino acids

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Proteins

• 10 to 35 of the calories in our diet should come
  from a combination of plant and animal proteins

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Vitamins and Minerals
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Vitamins Minerals

• Vitamins
• Organic compounds that are needed in minute
  quantities
• Usually function as coenzymes

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Vitamins
Table 15a.2 (1 of 2)
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Table 15a.2 (2 of 2)
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Nutrients

• Vitamins
• Water-soluble
• Fat-soluble
• Except for vitamin D, our cells cannot make
  vitamins and must obtain them from food

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Nutrients

• Minerals are inorganic substances that are
  essential to a healthy diet

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Minerals
Table 15a.3 (1 of 2)
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Minerals
Table 15a.3 (2 of 2)
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Water

• Water
• Transports materials through our blood and lymph
• Provides a medium for chemical reactions
• Is a lubricant
• Can serve as a protective cushion
• Plays an important role in the regulation of body
  temperature

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Nutrition and Weight Control

• MyPyramid is a food guide for planning a healthy
  diet
• Nutrients provide energy or have a structural or
  functional role in the body
• Food labels help us make wise food choices
• For body energy balance, calories gained in food
  must equal calories used

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MyPyramid Is a Food Guide for Planning a Healthy
Diet

• MyPyramid
• A food guide released by the U.S. Department of
  Agriculture (USDA) in 2005 for planning a healthy
  diet

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MyPyramid Is a Food Guide for Planning a Healthy
Diet
Figure 15a.1
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MyPyramid Is a Food Guide for Planning a Healthy
Diet
Figure 15a.1 (1 of 2)
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MyPyramid Is a Food Guide for Planning a Healthy
Diet
Figure 15a.1 (2 of 2)
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MyPyramid Is a Food Guide

• A healthy lifestyle includes
• Choosing food wisely
• Staying within your calorie needs
• Engaging in physical activity

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Food Labels Help Us Make Wise Choices

• Using the information on food labels can help you
  make healthy choices and compare different brands
  and ingredients

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Food Labels Help Us Make Wise Choices
Figure 15a.6 (1 of 2)
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Food labels can be misleading
Figure 15a.6 (2 of 2)
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Body Energy Balancing

• Bodys energy balance depends on
• The calories gained in food
• The calories used
• Unused food energy is stored
• Fat
• Glycogen

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Body Energy Balancing

• The body requires energy for maintenance of
• Basic body functions
• Basal metabolic rate (BMR)
• Physical activity
• Processing of the food that is eaten

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Body Energy Balancing

• Dietary guidelines for Americans include
• Fitness
• Making healthy food choices
• Avoiding foods that lead to disease

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Nutrition and Weight Control

• Obesity is body weight 20 or more above the body
  weight standard
• Successful weight loss programs usually involve
  reducing calorie intake, increasing calorie use,
  and changing behavior
• Anorexia nervosa and bulimia are eating disorders
  that create caloric deficits

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Obesity

• Obesity
• Body weight 20 or more above the body weight
  standard

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Obesity

• The Body Mass Index (BMI)
• Evaluates your weight in relation to your height
• Does not actually measure body fat
• Statistically correlates pretty well, but there
  are exceptions

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Obesity

• BMI does not correlate perfectly to percent body
  fat

• Maintaining a healthy weight is important to
  avoid cardiovascular disease, diabetes, and
  degenerative joint disease

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Weight Loss Programs
Figure 15a.8
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Anorexia Nervosa and Bulimia

• Weight loss can be dangerous
• Anorexia nervosa
• highest mortality rate of any psychiatric
  disorder
• Bulimia
• Intentional vomiting after eating
• Both can be fatal
• Eating habits associated with these disorders is
  thought to be the result of physiological,
  social, and psychological factors