Nutrition Terms Nutrition is a science that studies the

interactions between living organisms and food.

Nutrients and energy are provided by food. Energy is measured in calories. Essential nutrients must be provided by diet Nutrients are substances in foods required

by the body for energy, growth, maintenance, and repair.

Nutrient Density

Nutrient Density

MyPyramid does not clearly define low-fat and low-calorie food choices.

When making choices in each food group, nutrient dense foods are the best choice.

Nutrient density: the relative amount of nutrients per calorie of food.

Phytochemicals Phytochemicals: substances found in plant

foods that are not essential nutrients but may have health-promoting properties

Functional Foods Functional foods: foods that have health-

promoting and/or disease-preventing properties beyond basic nutritional functions

Food or Dietary Supplement?

What influences food choices?

•Traditional and ethnic foods

•Convenience

•Physical factors

•Psychological factors

•Social factors

•Philosophical factors

What influences food choices?

Classes of Nutrients: Macronutrients: Carbohydrates, Lipids and Protein

Classes of Nutrients: Macronutrients: Carbohydrates Primary source of fuel for the body,

especially for the brain Provide 4 kcal per gram Carbohydrates are found in grains

(wheat, rice), vegetables, fruits, and legumes, and milk

Classes of Nutrients: Macronutrients: Carbohydrates, Lipids and Protein

Classes of Nutrients: Macronutrients: Lipids

Are composed of lipids, molecules that are insoluble in water

Provide 9 kcal per gram Are an important energy source during

rest or low intensity exercise Are found in butter, margarine, vegetable

oils Are source of fat-soluble vitamins and

essential fatty acids

Classes of Nutrients: Macronutrients: Carbohydrates, Lipids and Protein

Classes of Nutrients: Macronutrients: Protein

Proteins are chains of amino acids Can supply 4 kcal of energy per gram,

but are not a primary energy source Are an important source of nitrogen

Classes of Nutrients: Micronutrients: Vitamins, Minerals and Water Micronutrients provide no energy but are

necessary for proper functioning of the body. Micronutrients include vitamins and

minerals. Micronutrients are very important for good

health, but are required in small amounts. Micronutrients can be found in most fresh

foods.

What Nutrients Do

What Nutrients Do

What Nutrients Do: Provide Energy Working together, macronutrients and

micronutrients help the body stay healthy. Biochemical reactions in the body help to

release the energy contained in carbohydrates, fats and proteins.

Energy is used to maintain body functions, fuel physical work and to repair the body.

If more energy is consumed than is needed, over time, body weight will increase.

What Nutrients Do: Form Structures Most of the weight of the body is due to

water, fat and protein. Nutrients help to form and maintain the

shape and structure of the body. Proteins form ligaments and tendons that

hold bones together and attach muscles to bones.

At the cellular level, lipids and proteins make up the membranes that surround cells.

What Nutrients Do: Regulate Body Processes All the reactions that occur in the body are

called metabolism. The proper regulation of metabolism is

called homeostasis. Each nutrient plays a role in helping to

maintain homeostasis. Water helps to regulate temperature. Protein, vitamins and minerals help to speed

up or slow down metabolic reactions.

Diet and Health: Undernutrition

Diet and Health: Overnutrition

Health: Genetics and Lifestyle

Choosing a Healthy Diet: Calories In = Calories Out

What Should I Eat?Eat a variety of foods Snack on something other than chips. Try trail mix that contains fruit and nuts. Add almonds and dried cranberries to your salad. Try a new vegetable or fruit each week. Tired of carrots? Try jicama. Vary your protein sources. Have fish one day and beef the next, or skip the meat and

have beans.

Balance your choices Going out to dinner? Have a salad for lunch. Add a vegetable instead of pepperoni to your pizza. When you have cookies for a snack, have fruit for dessert. Had soda with lunch? Have milk with dinner.

Practice moderation Push back from the table before you are stuffed and go for a walk. Reduce your portions by using a smaller bowl. Skip the seconds or split your restaurant meal with a friend. If you eat some extra fries, take some extra steps.

Nutrition is a Science Nutrition is a science. Developing an understanding of the

processes in nutritional science will help us to understand the relationship between nutrition and health.

Understanding nutritional processes will help us to make wise nutrition decisions.

The Scientific Method Advances in nutrition are made using the

scientific method. The scientific method uses an unbiased

approach to examine the interaction of food, nutrients and health.

The steps in the scientific method are: Observation Hypothesis Theory

The Scientific Method

What makes a valid experiment? A well-conducted experiment requires:

Quantifiable Data- Can we measure the information in a scientific

manner?

Appropriate Experimental Population- Is the population large enough and pertinent to

the study?

Proper Controls- Can we ensure that the population ate or drank

what we said they did?

Types of Nutrition Studies

Types of Nutrition Studies

Identifying Reliable Nutrition Information

For example, can you really lose forty pounds in one week

Does the information make sense? Where did the information come from?

Information from personal testimony or from one health care professional is probably not reliable.

Identifying Reliable Nutrition Information

How does this meal fit into a healthy diet?