chapter 1 nutrition

Question 1

what is nutrition

Answer 1

Nutrition on is the scientific study of food and nutrients and their-effects on body structure

Question 2

what are essential nutirtients

Answer 2

essential, meaning
that the body cannot make them itself and that they must be obtained from the diet. For example, essential amino acids,
essential fatty acids, vitamins, minerals and water are all essential nutrients. Other nutrients have important roles in the
body and can help us thrive, but they are not absolutely required from the diet for growth and survival

Question 3

how many categories nutrients are name them

Answer 3

Recall that there are six categories of nutrients: water, carbohydrates, lipids, proteins, vitamins and minerals.

Question 4

carbs

Answer 4

sugar, startch , fiber , organic , carbon chain , macronutirnets

Question 5

what are organic nutrients

Answer 5

Carbohydrates, lipids, protein and vitamins are organic nutrients, meaning that they are made of carbon chains.
Conversely, water and minerals are inorganic because they do not contain carbon.

Question 6

what are two groups of nutrients

Answer 6

Nutrients can further be divided into macronutrients and micronutrients. Macronutrients are found in higher
proportions in the body and are required in larger quantities es from the diet. Micronutrients are found in much smaller
quantities in the body and are required in smaller amounts from the diet.
The amount of a nutrient required does not
necessarily dictate how important it is. deficiency of both macronutrients and micronutrients can have negative effects
on health

Question 7

what is nutrinism

Answer 7

nutritionism a term that describes why reducing the effects of foods to the sum of their parts can be problematic. For
example, whether a food has carbohydrates in it alone does not tell us whether it is healthy or not. Understanding nutrition also requires an understanding of how nutrients and other substances in food interact with each other, as well as
how the effects of nutrients diff er between people

Question 8

name some non nutrients

Answer 8

Food and drink can also provide us with substances that are not classifi ed as nutrients. Phytochemicals, alcohol,
caff eine and toxins are naturally found in some of the foods and beverages we consume. They are sometimes referred to
as non-nutrients because they are not required for the growth and survival of the organism but are nonetheless found in
food. With respect to our health, these non-nutrients may have positive
effects (phytochemical),
negative effects (alcohol, toxins), or both (caffeine).
Phytochemical and toxins are explored below, while the psychoactive drugs caffeine and

Question 9

phytochemicals

Answer 9

Phytochemicals, or plant chemicals, are non-nutrients found in plants that may have positive health effects.
For
instance, they are believed to be partly responsible for the reduced risk of cardiovascular disease and cancer in those
who consume higher amounts of fruits and vegetables on to fruits
and vegetables, phytochemical are found in whole grains, beans, legumes, nuts and spices. Plants make phytochemical
to promote their growth and reproduce on .The more environmental stressors that a plant has,
the more phytochemical it tends to produce. The main categories of phytochemical are flavonoids
and carotenoids. They are responsible for the bright colours found in fruits and vegetables

Question 10

flavnoids

Answer 10

Flavonoids tend to promote a bright blue, red or dark colour pigmentation in plants. They are abundant in
parsley, blueberries, black tea, citrus fruits, wine and cocoa. They have anƟ -inflammatory, anti -tumour and anƟ oxidant effects

Question 11

caretenoids

Answer 11

Carotenoids contribute to the yellow, orange and red colours
found in plants such as pumpkins, sweet potatoes, carrots and squash.
Like flavonoids,
they have antioxidant effects. They can also be used to
synthesize vitamin A in the body and are accordingly associated with eye
health. They have further been shown to have positive effects on the
cardiovascular system as well as on cognitive function
To date, tens of thousands of known phytochemical have been
identical Since research is still ongoing and the effects of phytochemical
supplementation on remain unclear, there are no health claims that have
been approved by Health Canada for individual flavonoids.
However, a
diet that favours a wide range of plants of varying colours can provide a
variety of phytochemical

Question 12

toxins

Answer 12

Toxins are naturally occurring substances found in plants and animals that can have harmful eff ects on the
body.
Organisms make toxins as part of their metabolism or as a defence against predators.
Many foods contain toxins;
they are mostly unavoidable. This is typically not a cause for concern, however, because adverse effects from toxins are
relatively low (
. As Paracelsus, the 16th century father of toxicology famously said, “It is the dose that
makes the poison.” Indeed, almost anything, including water, can be toxic if it is consumed in excessive amounts.
It is important that toxins are consumed in low enough amounts that they do not become a poison. That is why
organizations including Health Canada and the US Food and Drug Administration. on limit the amount of toxins allowable in
food. The World Health OrganizaƟ on (WHO) further recommends several strategies we can use to limit the risk from food
toxins. These include discarding old, mouldy, bruised, damaged or discoloured food or food that does not smell fresh or
has an unusual taste (World Health OrganizaƟ on, 2018b). Since mushrooms and other wild plants can produce potent
toxins, they further recommended only consuming those that are non-poisonous, such as those sold at the grocery store

Question 13

food modification

Answer 13

Over the years we have seen many changes to our foods. For example, changes have occurred in the way foods
are grown, the geneƟ cs of foods and the substances added or removed from foods

Question 14

fortification of food

Answer 14

Many foods we fi nd at grocery stores have been forƟ fi ed, which involves increasing the amount of nutrients in
the food beyond what was there originally. A food manufacturer may do this because it is required according to government regulaƟ ons. For instance, the Canadian government mandates the addiƟ on of iodine to table salt and folic acid to
breakfast cereals. Manufacturers may alsoforƟ fy products with vitamins, minerals, essenƟ al faƩ y acids or fi bre to increase their marketability. Whether a food has been forƟ fi ed alone does not determine whether it is healthy or not. We
must look beyond what has been added and consider the food as a whole, including how processed that food may be.

Question 15

whole food

Answer 15

whole foods.
While almost all foods have some degree of processing, whole foods are those that remain as close to their natural form
as possible. These foods have had liƩ le to no refi nement and/or processing as well as few or no addiƟ ves and/or preservaƟ ves. Conversely, processed foods are those that have undergone signifi cant changes to their original form. The diff erences between the diff erent degrees of processed foods are outlined by the NOVA classifi caƟ on syst

Question 16

ultra processed foods and its risks

Answer 16

About half of Canadian food intake is from ultra-processed foods (Nardocci et al., 2019). This is concerning, as
ultra-processed foods have been linked with several health concerns. For instance, one study found that Canadians that
consumed the highest amounts of ultra-processed foods had a 31% increased risk of obesity, a 37% increased risk of
type 2 diabetes and a 60% higher risk of high blood pressure (Polsky & Moubarac, 2019). Furthermore, a study of over
100,000 individuals over a 10-year period found that those who increased their intake of ultra-processed foods by 10%
had a similar increase in the rate of cardiovascular disease (Srour et al., 2019). Conversely, those who consumed mostly
unprocessed or minimally processed foods had the lowest risk of disease. Another study of approximately 20,000 individuals found that those who ate the most ultra-processed foods (more than four servings per day) had a 62% increased
mortality risk compared to those who ate one serving or less per day (Rico-Campà et al., 2019). For each addiƟ onal serving per day of ultra-processed food, mortality risk increased by 18%! Research conƟ nues to illustrate the negaƟ ve health
eff ects of diets high in processed foods. The best way to minimize these eff ects is by focusing most of our food choices
on minimally processed whole foods

Question 17

nova classificatin osystem

Answer 17

1 - minimally processed
processed culinary
processsed
ultra processed

Question 18

nova group 1

Answer 18

These include plants and animals that have had minimal alteraƟ ons. They
are typically found intact and with minimal packaging. They are oŌ en found
in meals cooked at home or in restaurant kitchens. These foods may sƟ ll
have been dried, crushed, roasted, boiled, refrigerated or pasteurized,
which are processes meant to preserve foods as close to their natural form
as possible.

Question 19

nova group 2

Answer 19

These include oils, buƩ er, sugar and salt. They are made from foods found
in the fi rst category by pressing, refi ning and grinding them. These are
typically used in combinaƟ on with foods from group 1 and are not typically
consumed on their own.

Question 20

nova group 3

Answer 20

These are typically made from combining group 1 and group 2 foods. They
include canned foods, cheese, breads and fruits in syrup. Typically, processed foods have more than one processed culinary ingredient added
to a formerly unprocessed or minimally processed food. These foods are
typically made to enhance shelf life, taste and marketability.

Question 21

nova group 4

Answer 21

These foods have minimal amounts of group 1 ingredients. Instead, they
are made almost enƟ rely from the processed ingredients found in group 2
and group 3 foods. They oŌ en include lower-cost ingredients such as sugar
and salt. They are oŌ en found in brightly coloured packages and sold in
convenience stores. Sugar-sweetened beverages, chocolate bars, candy,
pre-packaged frozen dinners and deli meats are all examples of ultra-processed foods. Manufacturers make these foods to improve shelf life, taste,
marketability and ulƟ mately profi t.

Question 22

organic food

Answer 22

Organic foods are foods that have minimal syntheƟ c or arƟ fi -
cial inputs and are grown, raised and harvested in a way that preserves biodiversity.

Question 24

benefits of organic food

Answer 24

Many countries, including Canada and the United
States, have strict regulaƟ ons on what consƟ tutes an organic food
and foods cannot be labelled organic unless they meet these
Figure 1.4: A food can display an organic label if
it contains at least 95% organic contents.
specifi caƟ ons (Figure 1.4). In parƟ cular, the use of syntheƟ c pesƟ cides and ferƟ lizers is restricted. Organic processes may
instead be used in their place. For instance, manure, compost and crop rotaƟ on may be used to maintain the nutrient
quality and viability of soil. Moreover, organic foods are not geneƟ cally modifi ed and are farmed without the use of
hormones and unnecessary anƟ bioƟ
ganic foods are superior nutriƟ onally (Dangour et al., 2009; Smith-Spangler et al., 2012).
Organic foods do tend to have lower amounts of pesƟ cide residues (Barański et al., 2014) and lower nitrate levels (Barański et al., 2014; Huber et al., 2011). Whether this translates into beƩ er health for those who consume organic
products is not clear. There have not been enough long-term studies on the exclusive consumpƟ on of organic foods and
their eff ects on health. For now, whether to choose organic foods remains a personal choice.

Question 25

geneticlly modified food

Answer 25

GeneƟ cally modifi ed foods, also known as geneƟ cally engineered foods or geneƟ cally modifi ed organisms, are
foods that have undergone alteraƟ ons to their DNA through the process of geneƟ c engineering. We have been geneƟ -
cally modifying organisms for centuries. For example, we preferenƟ ally breed certain organisms with other ones in order
to get desirable traits in their off spring. That is how we get seedless grapes and watermelons as well as diff erent colours
of carrots. To be clear, the consumpƟ on of geneƟ cally modifi ed food does not change our own geneƟ cs. The plant or
animal’s geneƟ cs are slightly altered, but that does not get incorporated into our own DNA

Question 26

geneticly enginerred food

Answer 26

GeneƟ cally engineered crops may also involve the use of a vector to implant desirable traits into an organism
(Figure 1.5). This is typically done to improve the growth of that food, make it more resilient to environmental threats
or to boost its nutriƟ onal quality. For example, geneƟ c engineering has produced plants that are resistant to herbicides,
a type of rice (Golden Rice) that is higher in vitamin A and papaya plants that are resistant to the highly destrucƟ ve
ringspot virus. InteresƟ ngly, this last intervenƟ on is believed to have maintained the papaya industry in Hawaii where
ringspot threatened to bankrupt it (Stokstad, 2008). There are many other foods that are geneƟ cally modifi ed, such as
so-called cash crops. Cash crops are those that are heavily produced, sold and traded, such as corn and soy. Soy alone
accounts for about half of all commercially available geneƟ cally modifi ed foods worldwide (James, 2014)

Question 27

food aditivies

Answer 27

Food addiƟ ves are substances added to food for the purpose of taste, appearance, safety, freshness or other factors. There is a wide range of food addiƟ ves, including preserving agents like sodium nitrate, thickening agents like guar
gum and sweeteners like high-fructose corn syrup. For any of these substances to be approved for use in food processing, their safety must be evaluated. For instance, the Food and Agriculture OrganizaƟ on/WHO Joint Expert CommiƩ ee on
Food AddiƟ ves (JECFA) evaluates the safety of food addiƟ ves that are traded internaƟ onally (World Health OrganizaƟ on,
2018a). During their review process, an examinaƟ on of all scienƟ fi c evidence is performed. The short-term and long-term
eff ects, including any potenƟ al for harm are evaluated. If an addiƟ ve is approved, there is typically a recommendaƟ on for
the maximum amount that can be added to food. This amount will be below the threshold for harm, if there is one. Food
addiƟ ves are typically found in processed and ultra-processed foods. Anyone concerned about the eff ects food addiƟ ves
might have on health can easily minimize them by consuming more unprocessed NOVA group 1 foods.

Question 28

why do weeat

Answer 28

body structure , body function , energy , pleasure ,

Question 29

body structure.

Answer 29

The study of body structure is called anatomy.
Nutrients contribute to our anatomy in various ways.
Except for vitamins, nutrients can be found within most
body cells. For instance, cell membranes are made up of
lipids. Proteins and carbohydrates can be found embedded
within these membranes. The inner goo, or cytoplasm, of
a cell is made up of water and certain minerals like potassium and chloride are found within it.
Figure 1.6: Food promotes body structure and funcƟ on
and supplies energy to meet our needs.
The body is 60–70% water by weight, most of which provides structure to cells. Protein also adds structure to our
muscles, bones and teeth. Minerals harden our bones and teeth, making them stronger. Lipids provide body structure
and cushioning when they are stored in adipose Ɵ ssue. Together, these nutrients make the body structure capable of
performing its many funcƟ ons.

Question 30

body function

Answer 30

The study of body funcƟ ons is called physiology. At any given moment, the body is in the process of accomplishing millions of physiological tasks that keep us alive and help us respond to our needs. All nutrients contribute to physiology by being involved in various reacƟ ons and processes aimed at maintaining homeostasis. Homeostasis is a state of
dynamic equilibrium that allows our bodies to funcƟ on opƟ mally.

Question 31

energy provision

Answer 31

The body needs energy in order perform its various funcƟ ons and keep us alive. This is known as basal metabolism. In addiƟ on, the body needs energy to be able to perform the various acƟ viƟ es we do throughout the day. The more
acƟ ve an individual is, the more energy they require. Furthermore, we use energy to help process the food we eat and
to make heat. Only three nutrients provide energy to the body. Carbohydrates, lipids and proteins are the energy-yielding nutrients, providing 4, 9 and 4 kilocalories (Box 1.1) per gram, respecƟ vely. Alcohol also provides energy (7 kcal per
gram), but it is a drug, not a nutrient

Question 32

what is a calorie

Answer 32

A calorie is the unit used to measure food energy in Canada. It is the
amount of energy needed to raise the temperature of one gram of water by one degree Celsius. 1 kilocalorie is equivalent to 1000 calories.
We generally use the term Calorie (note: with a capital C) to denote a
kilocalorie. So, when we say there are 300 Calories in a food, we mean
there are 300 kilocalories or 300 000 calories in it.

Question 33

diet and healthy

Answer 33

Diet is one of the main factors that aff ects our health and risk for disease. In the short term, what we eat from
day to day can aff ect our energy levels and how our body feels. In the long term, what we regularly eat can aff ect our
risk for developing certain diseases. In fact, of the major causes of death in Canada,

Question 34

modifibale risk and unmodifabel

Answer 34

Modifi able risk factors include whether a person smokes, is
inacƟ ve or experiences a high degree of stress in their life. Unmodifi able risk factors include gender, age and geneƟ cs.

Question 35

diet gene interaction

Answer 35

GeneƟ cs and diet have an interesƟ ng relaƟ onship. Our geneƟ c makeup can infl uence our appeƟ te, the availability of nutrients, how those nutrients are used and their eff ects on the body as well as how we taste and experience food.
For instance, certain people have a geneƟ c predisposiƟ on to certain diseases, one that an unhealthy diet can exacerbate.
Neither our geneƟ cs nor diet can fully predict whether we will develop a disease or not, but they can each aff ect our
disease risk. While we cannot change our DNA, we can change our daily food decisions.
Th

Question 36

nnutritional epigentetics

Answer 36

Though diet cannot change the sequence of DNA we inherently have in our cells, it can aff ect the way genes are
expressed – that is, whether a segment of DNA will be coded into a funcƟ onal protein. The study of this interacƟ on is
called nutriƟ onal epigeneƟ cs. NutriƟ onal epigeneƟ cs explores how the foods we eat can change DNA expression, even
if the DNA code stays the same. This seems to be especially true during early life. For instance, a pregnant mother’s food
consumpƟ on can aff ect what genes are expressed and the risk for disease in her future child (Vickers, 2014). An example
of this phenomenon has been studied in a mouse model called the agouƟ mouse

Question 37

agouti mouse

Answer 37

AgouƟ mice have an altered version of the agouƟ gene. This geneƟ c change causes the mouse to have both a
yellow coat colour and obesity. Researchers fed pregnant agouƟ mice either a normal diet or one that was rich in something called methyl groups. The liƩ er of mice from the mother who was fed the normal diet were like their mother –
yellow, obese and prone to disease. However, the pregnant mice that were fed the methyl-rich diet produced a liƩ er that
was more brown, lean and not prone to disease. All other factors between the mice were the same – the only thing that
changed was the mother’s diet.
Methyl groups do not alter DNA codes, but they alter whether DNA can be expressed or not. A small change in
the mother’s diet led to a change in

Question 38

chosing a helathy diet

Answer 38

balance , moderation , variety , nutrient desnity

Question 39

balance

Answer 39

Dietary balance means to have things in the right proporƟ ons. This applies to the nutrients and energy we consume but also to the general choices we make. For instance, having too much of one nutrient and not enough of another
or consuming too much energy and not expending enough can both aff ect health. Balance can also refer to the healthy
and less healthy decisions we make. For instance, in our society it is diffi cult for many people to consume strictly unprocessed foods from NOVA group 1 in Figure 1.3, even though they most promote health. However, if most of the food we
consume comes from the ultra-processed food group, this can have negaƟ ve health consequences.
Balance means fi nding the right equilibrium
between these types of food. Balance does not mean
50/50 – it means fi nding the right proporƟ ons of the
things that help us achieve a parƟ cular result, in this
case health. A good rule of thumb when it comes to
nutriƟ on is 80/20. This means that 80% of our nutriƟ onal decisions should be ones that promote health, while
20% can be less healthy (Figure 1.11).

Question 40

variety

Answer 40

Dietary variety means consuming a diversity of foods
(Figure 1.12). No single food can provide all the nutrients in the
right proporƟ ons: some foods are high in some nutrients, while
others are high in other nutrients. The greater variety of foods we
consume, the less likely we are to develop symptoms of defi ciency. Defi ciencies are more common in people who avoid groups of
foods or have a less-varied diet.

Question 41

moderation

Answer 41

ModeraƟ on means not too much and not too liƩ le. In other words, it ensures that our diets are adequate, so we
do not develop nutriƟ onal defi ciencies, but not excessive to the point where they promote complicaƟ ons. For instance,
consuming insuffi cient sodium can negaƟ vely aff ect our body’s ability to send electrical signals. Conversely, too much sodium increases cardiovascular risk in some people. The concept of moderaƟ on also applies to the amount of energy we
take in. If we do not take in enough energy, we may feel Ɵ red and have a harder Ɵ me accomplishing our daily acƟ viƟ es.
Conversely, if we regularly overconsume energy, this puts us at a higher risk for obesity, type 2 diabetes and cardiovascular disease.

Question 42

nutrietn density

Answer 42

Nutrient density refers to the amount of nutrients in
a food or meal as compared to a reference amount. Typically,
a 100 kcal reference amount of food is used. Figure 1.13 compares the nutrient density of a cola beverage to 2% milk. In this
example, we see that in 100 kcal of milk we have a high quanƟ ty
and variety of nutrients. In comparison, 100 kcal of cola provides
mostly sugar.

Question 43

nutrient porfilling

Answer 43

The science of ranking foods based on nutrient density is called nutrient profi ling. There are several ways in
which this is done, but the focus of these techniques is to diff erenƟ ate between foods that are high in essenƟ al nutrients,
like protein and vitamins, and lower in nutrients that may increase risk of disease when consumed excessively, like trans
fat (Drewnowski et al., 2019). In general, whole foods tend to be more nutrient dense than processed and ultra-processed foods. Consuming more of these NOVA group 1 foods and less of the group 3 and 4 foods, can increase the nutrient density and healthfulness of our diets.

Question 44

the study of nutrients

Answer 44

NutriƟ on is the study of the foods we eat and their eff ects on us and our environment. I

Question 45

what are osem study methode

Answer 45

Epidemiological and experimental research are the two main methods used to study nutriƟ on. Each has
strengths and weaknesses.

Question 46

experimental studie s

Answer 46

Experimental studies are oŌ en called randomized control trials. They are the gold standard for making inferences from research. This is because they control all variables, except for the one factor that is being studied. For
instance, to test whether a certain dietary supplement improved alertness, two idenƟ cal groups where everything was
executed the same way would be needed; the only diff erence being that one group would consume the supplement
while the other would not. Using this controlled procedure means that when an eff ect is seen aŌ er a study, it is most
likely due to that one variable that was changed. For instance, if the group receiving the dietary supplement had signifi -
cantly higher levels of perceived alertness, we would aƩ ribute that aff ect to the supplement, as everything else was the
same between groups. In this example, the group receiving the dietary supplement is the experimental group, while the
one that didn’t receive the supplement that was used for comparison purposes is the control group. To reduce the risk
of intenƟ onal or unintenƟ onal bias that could aff ect the results, control groups are oŌ en given a placebo. For instance,
the control group may be given a fake supplement – a sugar pill that has no eff ect on the body.
A well-conducted experiment involving humans will have

Question 47

blind and double blind study

Answer 47

hese are outlined in Figure 1.15. However,
there are very few, if any, studies that fi t all these criteria. Typically, the more checks on this list, the beƩ er the study is, and the
more credible the results. For instance, a well-designed experiment may be blind, or beƩ er yet, double-blind. A blind study
means that neither the experimental nor control group knows
which group they are in. They just know what the experiment
is about and that they might receive an acƟ ve treatment or a
placebo. This lowers the chance for bias and any psychological or
unintenƟ onal eff ect that could aff ect the parƟ cipants’ behaviours
and the study’s results. A double-blind study is one where neither the scienƟ sts nor the subjects know which group is receiving
the experimental treatment and which is receiving the placebo.
This reduces the chance for bias from the experimenters as well.
While experimental studies are best at establishing
causality, human nutriƟ on studies are diffi cult to perform and
have several limitaƟ ons. For one, it is diffi cult to force a person
do something. Also, some people may drop out of a study or not
follow the instrucƟ ons given by the researchers. Further, we

Question 48

epidemiological studiez

Answer 48

Because human nutriƟ on experiments are diffi cult, Ɵ me-consuming, costly and someƟ mes unethical to conduct,
an epidemiological design is typically used to study nutriƟ on. Epidemiological studies, also known as populaƟ on-based
studies, look at trends in populaƟ ons without manipulaƟ ng any variables. For instance, instead of asking a populaƟ on
to consume a diet high in fi bre, as we might do in an experimental study, in an epidemiological study we may look at
populaƟ ons that already consume a high fi bre diet and compare them to those that do not. A good example of this type
of research is the Nurses’ Health Study, a series of studies that started in 1976 and followed nurses forward through
Ɵ me (Colditz et al., 2016). The researchers gathered informaƟ on about these nurses including their dietary paƩ erns as
well as other health-related metrics such as whether they smoke, exercise or have a family history of disease. Over Ɵ me,
some of these nurses developed heart disease, cancer and other diseases or died. Since the researchers had a lot of
informaƟ on about these nurses’ habits, history and health, they could then look at whether there were certain habits
or condiƟ ons that were more common in the groups that developed disease or died prematurely. For instance, one of
the most notable outcomes of this study was that women who had higher intakes of saturated fat were more likely to
develop cardiovascular disease. The same was found in an epidemiological study of men called the Health Professionals
Follow-up Study (Zong et al., 2016). Both studies followed a prospecƟ ve epidemiological design, where a large, similar
group is followed forward through Ɵ me.A criƟ cal point to understand about epidemiological studies is that associaƟ on does not equal causaƟ on. For
instance, just because a link was found between two factors (i.e., saturated fat and cardiovascular disease) it does not
mean one leads to the other (i.e., high saturated fat intake leads to cardiovascular disease). In epidemiological studies,
we cannot control all the variables that may infl uence disease. For instance, perhaps women who eat a high saturated
fat diet are also more likely to have other lifestyle factors that increase their risk of CVD; perhaps it is not the saturated
fat in the foods they consume that increases their risk, but the foods they ate that are high in saturated fat; perhaps the
way we collected informaƟ on about their dietary habits misrepresented them.
For all these reasons and more, it is important to not look at epidemiological evidence alone, and instead combine it with what has been found in other studies that used diff erent research methods. This is what makes nutriƟ on
confusing for a lot of people. We may read one headline that says one thing, but another that says something else. A
good way to think about it is that each study is a certain piece of the puzzle, but none can show the full picture alone.
Another major weakness of epidemiological studies is the lack of accuracy in determining a populaƟ on’s diet.
For instance, how do we accurately gauge the quality and quanƟ ty of a person’s diet? Table 1.1 provides an overview of
the typical ways diet is assessed in these studies, including their strengths and potenƟ al limitaƟ on

Question 49

other study methods

Answer 49

Biochemistry, molecular biology and computer modelling techniques can also be used to study nutriƟ on using
the scienƟ fi c method. While these add to our knowledge base, they cannot always account for the complex interacƟ ons
between foods, diets and the human body.

Question 50

anectodal evidence

Answer 50

Evidence is a body of facts and informaƟ on that helps us determine whether something is true or valid. This
textbook, as well as all nutriƟ on-focused journal arƟ cles, primarily use experimental and epidemiological evidence to
assess the eff ects of nutriƟ on on health. These scienƟ fi c methods and results, however, are rarely highlighted on the
internet and in social media. Anecdotal evidence is what is typically used to sell products and sway opinions. Anecdotes
are personal tesƟ monies drawn from direct or indirect casual experiences. For instance, an Instagram post may feature
an infl uencer selling a weight loss supplement with a before and aŌ er photo staƟ ng how well the supplement worked for
them. But beware – just because someone says something worked for them it doesn’t mean it is safe and will work for
someone else.
Many infl uencers are paid to sell products that
they do not even use (Figure 1.16). In Canada, infl uencers must disclose whether an ad is sponsored. Look for
the hashtags #ad, #sponsored, #XYZ_ambassador, #XYZ_
partner to know if the person has been paid to post an
ad (Ad Standards Canada, 2019). This shows that they
may be biased and not providing credible informaƟ on.
Furthermore, just because someone provides an anecdote that something worked for them or someone they
know, it does not mean it is safe, eff ecƟ ve, sustainable
or backed by good science. While anecdotal evidence is
emoƟ onally convincing and parƟ cularly eff ecƟ ve in adverƟ sements, it can be deceiving and potenƟ ally harmful
to health if we follow the wrong guidance.

Question 51

peer review

Answer 51

So far, we have explored the process of collecƟ ng data through experimental and epidemiological studies. CollecƟ ng data is important, but it is also imperaƟ ve that this data is analyzed properly and thoroughly evaluated, and that
accurate conclusions are drawn. This typically takes the work of a skilled research team whose work is further reviewed
and assessed through a process called peer review. Before a scienƟ fi c arƟ cle can be published, it must be reviewed by
experts in the fi eld who were not involved in the study process to make sure the study was properly conducted, the
results were properly analyzed, and conclusions were properly drawn. Many arƟ cles found on the internet have not undergone peer review and are more likely to be misleading or false.

Question 52

finding credible articles

Answer 52

ollowing the peer-review process, if an arƟ cle summarizing a nutriƟ onal study is accepted, it will be published in a
research journal. Some journals have a higher threshold for the
quality of studies and results that they will publish. A journal’s
impact factor is a way of determining its importance and rank
based on how many Ɵ mes its arƟ cles have been cited by other
researchers. Pubmed (Figure 1.17) is an excellent search engine
that can be used to search for peer-reviewed journal arƟ cles
about nutriƟ on and human health as well as a wide range of
health-related topics. Google Scholar and a university library
search engine can also be used to fi nd scienƟ fi c arƟ cles

Question 53

evalutaong credible ources

Answer 53

While scienƟ fi c journal arƟ cles are the gold standard of credible sources, they typically require a knowledge of
science and scienƟ fi c terminology to be understood. Primary journal arƟ cles, those that summarize a scienƟ fi c study,
are oŌ en highly specifi c and it may be challenging to fi nd more general answers. That said, the introducƟ on secƟ on of
many arƟ cles typically gives a broader overview of the topic before the specifi c study is outlined. Review arƟ cles may be
more helpful for general quesƟ ons, as they oŌ en summarize diff erent studies to give a broader sense of a phenomenon.
We can use the word “review” in our search criteria in addiƟ on to topic keywords to search for these types of arƟ cles.
A review arƟ cle that can be helpful for broader perspecƟ ves is a systemaƟ c review. SystemaƟ c reviews involve a panel
of topic experts reviewing a wide range of primary research studies and evaluaƟ ng the strength of evidence to support
or not support a phenomenon. SomeƟ mes, new analyses and staƟ sƟ cal tools are applied within a systemaƟ c review to
come to new staƟ sƟ cal conclusions. This is called a meta-analysis. Figure 1.18 outlines the hierarchy of evidence credibility and illustrates what informaƟ on is more likely to properly represent the evidence.
This textbook will primarily use systemaƟ c reviews to support statements that are made. SomeƟ mes, other
review arƟ cles or primary research, such as randomized control trials and epidemiological studies, may also be used to
highlight a poin

Question 54

indiginous lens on nutrition

Answer 54

Two-eyed seeing is the pracƟ ce of equally using both a Western
science lens as well as an Indigenous ways of knowing lens to help us
understand things. TradiƟ onally, schools have employed only a Western
science lens, but this is changing. For example, the BriƟ sh Columbia and
Ontario school boards both recommend that teachers broaden students’
understanding of the natural world by bringing in Indigenous culture,
knowledge and voices in addiƟ on to its scienƟ fi c study.
There are some signifi cant diff erences between these two lenses. For instance, in Western science we oŌ en reduce food to its nutrient
content and then study the eff ects of individual nutrients on the body.
We see food as a non-living thing that we take from the earth for our own
benefi t. Conversely, tradiƟ onal and modern Indigenous cultures typically
see food as a dynamic, living enƟ ty, one that forms part of our relaƟ onship with each other and the land. They may give to their food system as
much or more than they take from it. For this reason, Indigenous food
systems and relaƟ onships are being studied by many Western scienƟ sts,
as they are oŌ en seen to be more holisƟ c, healthy and environmentally
sustainable than our current food systems.
It is important to note that there is not one Indigenous culture
or viewpoint in Canada and there is much diversity in their pracƟ ces,
locaƟ ons, urbanizaƟ on and occupaƟ ons. Indigenous Peoples are oŌ en
categorized according to three main groups found in the land known as
Canada: the First NaƟ ons, Inuit and MéƟ s. Within these groups there are
diff erent tribes, each with their own concerns and perspecƟ ves. Unfortunately, colonizaƟ on silenced many of these Indigenous perspecƟ ves.
However, there is now more interest than ever to understand and voice
them. While this textbook is wriƩ en by a non-Indigenous person, eff orts
have been taken to properly represent Indigenous perspecƟ ves with
respect to many nutriƟ on topics. Whenever possible, Indigenous voices
are used to represent the variety of beliefs, pracƟ ces and consideraƟ ons
of the many Indigenous people. The intent is to improve our two-eyed
seeing; to use a diff erent lens alongside our Western views of nutriƟ on,
thus painƟ ng a more holisƟ c picture.

Question 55

evaluating nutirnet source

Answer 55

veto