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5. The science of proteomics has allowed us to progress significantly in terms of understanding how proteins are
sequenced and how errors in sequencing can impact an individual’s health. The Human Genome Project has
also projected the biological sciences significantly further in understanding the human body and genetic
conditions. Briefly, discuss how proteins might undergo a sequencing error and how that might impact one of
the protein functions.
Answer: Proteins are sequenced through a process that is quite complex, but is described in this chapter as a
two-step process: transcription and translation.
6. The Human Genome Project is forging the way for many scientists, including the nutrition science field.
Discuss some of the pros and cons of this project for clients and professionals in the nutrition field.
Answer: Students are being asked to use not only the information in the text to answer this question but also to
develop a heightened understanding for how clients as well as professionals might react to the changing
paradigms that form nutrition education programs with the Human Genome Project. As science advances, some
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understand what types of genetic risks the fetus may have and make their family planning decisions based on
such information. Again, in some cases, nutrition and nutrition education could be a vital part of improving the
outcome or enhancing the outcome for these clients.
Food Production: While there are already many examples of genetic engineering in the area of agriculture, the
Human Genome Project does open the possibility for many new areas. Given that we are already capable of
producing babies and animals in test tubes, clearly the possibilities to develop, grow, and invent many types of
food products are endless.
The goal in genetic engineering of fruits and vegetables and/or food products is to be able to develop and
produce a “better” product by manipulating the genetic profile with the best profile possible and then producing
the items in the best environment possible.
Genetic testing is an expensive undertaking. Who pays for this testing? Is it required or optional? If the
individuals find out that they have a genetic profile for a particular illness, how can a system be developed to
optimize the chances that that particular client will follow the medical, nutritional, and lifestyle regime that is
required to minimize the health care costs? Who would be responsible for oversight of that system? Should
clients be required to follow any particular regime if they are genetically profiled for a particular disease?
Should they be denied medical care if they do not follow their prescribed program?
While the information from a genetic profile could be quite helpful to an individual, some individuals may not
want to be informed in advance of such information. Some individuals would “rather take their chances” and
live life as it is played out. Critics of genetic counseling believe that it takes the spontaneity out of living and in
some cases places the individual in a mode of “waiting for the other shoe to drop.” These individuals see having
such information as a burden rather than a window of opportunity. Others believe that information from the
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Therefore, there are a few more years to wait before the final verdict is in on genetic engineering of products,
etc.
Given the advance knowledge of a potential illness, the RD can work with clients to fully realize better health
and better eating habits. Many individuals retain poor eating habits as a result of “denial” that they will be
confronted with any adverse health event. However, if the client is assured that they are genetically coded for
any particular disease, this knowledge can heighten their willingness to faithfully follow better nutritional
habits. Given that nutritional habits are often similar among family members, if one family member retains
positive dietary habits, the changes are very good that the remaining family members will also follow similar
positive dietary habits. The potential for this type of trend throughout the United States could potentially reduce
obesity, cardiovascular disease, and many chronic diseases that are a result of poor nutritional/dietary habits.
Genetic engineering also has the potential to provide consumers with new, flavorful, and healthful food
products not formerly available through their innovation and creation. Consumers look for new food products
that “break neither the bank nor the waistline” and science may provide some of those answers. Food
manufacturers work hard to provide consumers with options. Though they are not genetically engineered,
products such as the fat replacers and alternative sweeteners are examples of recently developed diet
alternatives. It is important for the RD to stay current with all new products as consumers will challenge the RD
about them.
Cons for Nutritional Professional: Innovation is a wonderful thing but what happened to “leaving well enough
alone and living for today”? As noted with the consumer or client, even if genetic information is available to
them to assist them in making the most informed medical decision, the client may well want to be uninformed.
And, as with the client, who then becomes responsible for the number of issues that surround such decisions?
While some clients may be more motivated to follow strict dietary plans if they know that they are genetically
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prone to a heart attack, others may believe that there is nothing that is going to stop it so why not “live for
today”?
Nutrition education/counseling for a population that has available to them a massive amount of genetic
information can be complex without some standard guidelines. It will be important for the American Dietetic
IM Worksheet Answer Key
Worksheet 6-1: Nitrogen Balance Calculations
1a. 135/2.2 = 61 kg; 61 x 0.8 g/kg = 49 g
1b. NI = 38/6.25 = 6.08; NL = 8 + 4 = 12; NB = 6.08 – 12 = -5.92
Worksheet 6-2: Significance of Amino Acids
Client
Essential
Non-essential
Conditionally
Acquired
Sequencing Error
Newborn baby
diagnosed with PKU
X
↑ Phenylalanine
X
↓ Tyrosine
X
Autosomal recessive
disorder
Elderly female
diagnosed with PEM
20% BSA
(leucine, valine &
X*
Variable amino
acids levels seen →
X*
Variable amino
acids levels seen →
X*
Variable amino
acids levels seen →
Worksheet 6-3: Quick Protein Intake Assessment – Answers will vary.
Worksheet 6-4: Chapter 6 Crossword Puzzle
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Worksheet 6-5: Proteins from Foods (Internet Exercise)
Canadian Information9
6.1 Canadian Recommendations for Intake of Protein for Healthy People
The Canadian recommendations concerning intake of proteins are the same as those summarized in the margin on
page 192 of the textbook.
Eating Well with Canada’s Food Guide
• Drink skim, 1%, or 2% milk each day.
• Have meat alternatives such as beans, lentils and tofu often.
• Eat at least two Food Guide Servings of fish each week.
• Select lean meat and alternatives prepared with little or no added fat or salt.
Dietary Reference Intakes
6.2 Protein Intake of Canadians
The Canadian Community Health Survey (CCHS), Cycle 2.2 on Nutrition, conducted in 2004, collected 24-hour
dietary recall and related data including physical activity, chronic health conditions, lifestyle choices, food security,
6.3 Protein Regulations for Canadian Food Labels
The amount of protein in grams per serving of stated size is a core requirement in the Nutrition Facts table on food
labels11; however, a %DV for protein is not required, as Health Canada recognizes that protein intakes are generally
adequate, and not a public health concern for Canadians who consume a mixed diet.12 This protocol is similar to that
used for the U.S. food labels, but differs in that %DV is required to be listed if a claim is made for protein, such as
“high in protein.” Otherwise, unless the food is meant for use by infants and children under 4 years old, %DV for
protein is not required in the Nutrition Facts table on food labels in the United States.
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6.4 Amino Acid Supplements
Amino acid supplements are regulated under the Natural Health Products (NHP) Directorate of Health Canada.13
The Natural Health Products Regulations for labelling and packaging new natural health products have been in
force since January 2004; however, dates for obtaining required identification numbers and labelling on existing
products were extended to the end of 2009. All NHP must display an eight-digit natural product number (NPN) or
Highlight 6: Nutritional Genomics
A Canada Research Chair in Nutrigenomics, held by Ahmed El-Sohemy at the University of Toronto, investigates
identification of molecular targets of nutrients and of the genetic basis for individual responses to diet. The
relevance of this young field of research is to provide a scientific basis for making dietary recommendations to
prevent chronic diseases and advance the development of foods to improve health of Canadians. How genetic factors
affect our response to diet and how dietary factors can alter the expression of genes—particularly those related to
health and disease—is a new and rapidly growing field of research in Canada.
Canadian Web-Based Resource
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Worksheet 6-1: Nitrogen Balance Calculations
Nitrogen Balance Studies
Nitrogen Balance (NB) = Nitrogen Intake (NI) – Nitrogen Loss (NL)
NB > -5g/day = severe stress
NB = 0 to –5g/day = moderate stress
For each of the following examples:
a. Calculate the client’s recommended protein intake.
b. Calculate the client’s NB.
c. Indicate whether the client is in + or – nitrogen balance.
d. Discuss the implications of the findings.
1. 45-year-old female, weight 135 lbs., protein intake of 38 grams and UUN = 8 grams
a.
b.
c.
d.
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Worksheet 6-2: Significance of Amino Acids
Amino Acid Concept
Application
Essential
Must be provided to the body in that form; absence is incompatible with life
Non-essential
Can be made by the body using other sources
For each of the following clinical examples, indicate whether the client is at risk to develop a problem related to
amino acids.
Client
Essential
Non-Essential
Conditionally
Acquired
Sequencing Error
Newborn baby
diagnosed with PKU
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Worksheet 6-3: Quick Protein Intake Assessment
Most people in the United States and Canada receive more protein than they need. This is not
surprising considering the abundance of food eaten and the central role meats hold in the North
American diet. Using your food diary from the Self-Study in Chapter 1, estimate your protein
intake for the day. Multiply the number of servings you consumed by the estimated protein per
serving to guesstimate your total protein intake.
Food groups
Servings consumed
Estimated protein
Totals
Grains
3 grams/serving
Vegetables
2 grams/serving
Total estimated protein intake:
The protein RDA for young adults (19 to 24 years old) is 46 grams for women and 58 grams for
men. Health experts advise people to maintain moderate protein intakes—between the RDA and
twice the RDA.
1. Do you receive enough, but not too much, protein daily?
Fruit
0 grams/serving
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Worksheet 6-4: Chapter 6 Crossword Puzzle
Across:
Down:
4. many (10 or more) amino acids bonded together
6. above-normal alkalinity (base) in the blood and
body fluids
7. three amino acids bonded together
1. two amino acids bonded together
2. compounds that help keep a solution’s acidity or
alkalinity constant
3. above-normal acidity in the blood and body fluids
1 2
3
4 5
6
7
8
9
10
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Worksheet 6-5: Proteins from Foods (Internet Exercise)
not close the window until you have answered all of the questions.
On the website, click on Protein to answer questions 1 through 3.
1. Complementary proteins do not include all of the essential amino acids.
a. True
b. False
2. Research studies have changed the idea that foods must be eaten at the same meal to achieve the concept of
3. Match the amount of protein with the food selection.
a. ½ cup of milk
b. 3 ounces of meat
c. 1 cup of dry beans
quiz, and use the information/answers obtained to answer the following questions. Do not close the window until
you are done answering the questions.
4. The daily RDA requirement for protein is 0.8 g/kg.
5. Proteins can be used interchangeably in the body because they have similar structures.
a. True
b. False
6. Yogurt is an example of an incomplete protein.
7. The Daily Value for protein is 50 grams.