Nutrition Study

What are two advantages of using animals instead of humans in nutrition experiments? What are two disadvantages?

Advantages: may be less costly, easy to control food intake and measure excretions, changes appear quickly Disadvantages: the best models are expensive and have long life span, most readily accessible animal models have short life spans so observed changes may not be identical to humans in how they develop

Which of the following yields energy but is not considered a nutrient?

Alcohol

What is the difference between a depletion-repletion study and a balance study? How is each used in the field of nutrition?

Depletion-repletion: used to study the function and/or requirements of a nutrient. Subjects are fed a diet without the nutrient until symptoms appear, then the nutrient is added back until symptoms disappear. A balance study also looks at functions and requirements but compares the amount of a nutrient that enters the body with what is excreted. When the amount consumed equals the amount excreted, the body is in balance. This technique measures the minimum amount of nutrient needed to replace losses.

Name some reliable sources of nutrition information.

Dietitians, Physicians, government recommendations, non-profit educational organizations, and universities.

In a controlled study, if neither the subjects nor the investigators know which subjects are receiving treatment, the study is called a(n)

Double Blind Study

When evaluating a nutritional study, which is the least important factor?

How many researchers were involved in the study

_____________________ protects human subjects in a study and limits the types of procedures that can be performed on them.

Informed consent

Which of the following statements about the typical American diet is true?

Intake of whole grains is low and more energy is consumed than expended.

Which of the following is the BEST reason to include a placebo in the experimental design of a human intervention trial?

It helps prevent the expectations of the subjects from biasing the research.

The energy provided by foods is measured in:

Kilocalories

Nutrients are classified according to their chemical properties. What are the six classes of nutrients? Which are macronutrients? Which are micronutrients?

Macronutrients: Water, Carbs, Proteins, Fats Micronutrients: Vitamins, Minerals

Where do most people in the U.S. get their nutrition information?

Mass media, i.e., television, magazines and newspapers

Which of the following nutrients are NOT organic molecules?

Minerals

Describe the three general functions of nutrients.

Provide energy: Carbohydrate, protein and lipids undergo biochemical reactions that provide energy for synthesis, basic body functions and physical activity Forming structures: bones, muscles, cells are formed from protein, fats, minerals Regulating Body Processes: all 6 classes of nutrients regulate various body processes and function to maintain homeostasis

Which of the following functions is performed by members of all six classes of nutrients?

Regulate body processes

Which is NOT a true statement about nutritional studies using animals?

Results from animal studies can always be readily extrapolated to humans

Which of the following is NOT considered a macronutrient?

Vitamins

Which of the following is LEAST likely to affect food choices?

Weather

Which of the following conditions does NOT represent a state of malnutrition?

Weight loss as a result of increasing physical activity.

One important principle of a healthy diet is to eat a variety of foods. In this context, "variety" refers to:

choosing a variety of foods from within food groups as well as among food groups.

Eating turkey on Thanksgiving is an example of making a food choice based on:

cultural and family background.

Consuming nutrient-dense foods helps to ensure a proper diet. One effective strategy is:

eating foods that have been minimally processed. consuming foods with a high nutrient content compared to the kcalories provided. limiting added fats and sugars.

Under-nutrition does not include

eating too much saturated fat.

A substance found in plants which cannot be made by the body and is not necessary to sustain life, but has healthful benefits, is:

phytochemical.

Describe the steps involved in conducting a valid experiment using the scientific method.

1. Make an observation and ask questions. 2. Propose a hypothesis-a possible explanation of the observations. 3. Design an experiment to test the hypothesis that provides objective data. 4. Establish a theory based on experimental data from multiple studies.

A serving of hot chocolate provides 5 grams of fat, 2 grams of protein and 28 grams of carbohydrate. How many kcalories are in the serving of hot chocolate?

5 X 9= 45 2 X 4= 8 28 X 4=112 165 kCalories

Which is an example of anecdotal information?

A famous runner reports having more energy after eating a certain type of power bar.

Describe what is meant by the term control group and explain why a well designed experiment includes a control group.

A group of participants in a study who are treated the same as subjects in an experimental group, except that no experimental treatment is implemented. They would receive a placebo to control bias. A control group is used as a basis of comparison.

What is true regarding the differences between a hypothesis and a theory?

A hypothesis is an educated guess and a theory is based on scientific study and reasoning.

Which of the following would be the LEAST reliable source of information about herbal supplements?

A pamphlet published by the health food store

Describe the typical American diet and explain how it could be improved. Is there anything you would like to change about the way you eat? Why or why not?

Americans are consuming more food and calories than 30 years ago because portion sizes have increased and 32% of calories are from meals away from home. These meals tend to be higher in energy, fat, sugar and salt. Americans do not eat enough whole grains, legumes, fruits, dairy foods, and dark green or yellow vegetables. Salt and sugar intake are higher than recommended.

Which of the following describes a hypothesis?

An educated guess made to explain an observation.

What is the difference between a single-blind and a double-blind study? Why are double-blind techniques used?

Single - the subject or researcher does not know who is receiving the intervention. Double - neither the participants nor the researcher know who is in experimental group and who is in the control group. The double-blind technique is used so that neither the subjects' nor the researchers' expectations bias the results of the experiment.

Which of the following is likely to limit the availability of food?

Socioeconomic status Health status Where a person lives

Which of the following is a common source of anecdotal evidence?

Testimony of individuals

Continued acceptance of a scientific theory depends on

The ability of other scientists to duplicate the original research and results.

People's food choices are affected by many factors other than the nutritional value of the food. Select two of the factors that affect food choices and explain how you would use this factor to help reinforce a dietary change an individual is trying to make for nutritional reasons.

The factors to choose from are: (actual answer will vary) Availability Cultural and Family Background Personal Preference Psychological and Emotional Factors Health Concerns

Americans are replacing more and more home cooked meals with meals from fast food restaurants. a) What are the nutritional impacts of this trend? b) How does this trend influence disease risk?

a) Larger portions increase energy intake beyond needs; tend to be higher in fat, sodium, and sugar. b) Along with lack of physical activity, increases risk of chronic diseases such as diabetes, obesity, heart disease, and cancer.

An adverse or toxic reaction is most likely to occur if

an individual overuses vitamin and/or mineral supplements

A processed food is defined as

any food that has been changed from its natural state.

Comparison of the amount of a particular nutrient consumed with the amount of the nutrient excreted is characteristic of a(an)

balance study

Approximately 1000 college students were asked to keep a record of what supplemental vitamins they took and how many colds they had over the course of a year. The amount of vitamin C consumed was compared with the students' incidences of colds. This is an example of a(an)

epidemiological study

Physiologic processes take place in the body to keep body temperature, heart rate, and blood sugar relatively constant. This stable state is called:

homeostasis.

One group of individuals is asked to eat a diet high in fruits, vegetables and dairy foods while a second group of individuals is asked to eat a diet with lower amounts of fruits, vegetables and dairy foods. The two groups' blood pressure readings are monitored and compared. This is an example of a(an):

intervention study

The correct sequence of events in the scientific method is:

make an observation, develop a hypothesis, conduct the experiment, and form a theory.

A measure of the nutrient content of a food compared to its energy content is referred to as

nutrient density.

The discipline which explores the relationship between genetic variation and nutrition is called:

nutrigenomics

Researchers are interested in whether caffeine has any effect on short-term memory. A study is designed in which two groups of subjects are given capsules that look identical. Group A receives capsules containing caffeine and Group B receives capsules containing powdered sugar. Group B is being given a:

placebo.

Processed foods and convenience foods tend to ______ compared to freshly prepared foods.

provide more kcalories contain fewer nutrients be higher in fat, sugar, or salt

The recommendation to eat everything in "moderation" refers to

selecting appropriate portion sizes.

When subjects do not know which treatment they are receiving in a clinical trial, but the researchers do, the study is called

single blind