Download Working Your Way Through the Fat Maze

Working Your Way Through the Fat Maze
It can be challenging to work your way through the unending maze of dietary fat definitions,
with words like polyunsaturates, trans fatty acids and cholesterol. What do they mean? After
reading and re-reading these fact sheets and completing the activities, you will understand
what some of the words mean and what you can do to live a healthier lifestyle.
Fats
Fats or oils are lipids and occur naturally in food. They provide our bodies with a source of
energy as well as giving food flavor and a mouth-feel, which we all enjoy. Fats are referred to as
invisible and visible. Invisible fats are found in foods such as meat, fish, dairy products, eggs,
nuts and seeds. Visible fats are shortening, lard, salad and cooking oils, margarine and butter. If
these fats are incorporated into baked or cooked products, they are also referred to as invisible
fats.
Fats play an important role in nutrition. They provide a concentrated source of energy for our
bodies, act as body insulation and protection and transport fat-soluble vitamins (A, D, E and K)
to the small intestine for digestion. Fats also play an important role in food preparation. They
are used as tenderizing agents in baked products, as major components in salad dressing and
mayonnaise, as a heat-transfer medium in frying foods and as table spreads.
The term “fat” describes a broad group of substances that are insoluble in water and have a
greasy feel. Lipids that are solid at room temperature are called “fats” and those that are liquid
are called “oil.”
Fats or lipids are classified as:
Fatty acids
Triglycerides
Phospholipids
Sterols
Fatty Acids
Fats and oils are made up of basic units called fatty acids. Fatty acids are the building blocks of
fats, just as amino acids are the building blocks of protein. A fatty acid is a chain of carbons
linked together and flanked by hydrogen atoms. Fatty acids differ in the length of the chain of
carbon atoms and in the amount of hydrogen atoms attached to the carbons. Each type of fat is
a mixture of different fatty acids. Most fatty acids travel in threesomes as part of larger
molecules called Triglycerides.
Types of Fatty Acids:
Saturated Fatty Acids
 Saturated fatty acids are found chiefly in animal sources such as fat in meats, milk fat
and butter.
 They are usually solid at room temperature.
 Three vegetable oils, coconut, palm and palm kernel oil, are also highly saturated.
 Studies show an association between increased intake of saturated fatty acids and
increased low density lipoprotein—LDL (bad) cholesterol. Increased blood cholesterol, in
turn, has been associated with increased risk of heart disease.
 Saturated fatty acids are made up of a single chain of carbon filled with hydrogen.
Monounsaturated Fatty Acids
 Monounsaturated fatty acids are found mainly in vegetable oils such as canola, olive and
peanut oils.
 They are liquid at room temperature.
 Studies indicate that monounsaturates may lower LDL (bad) cholesterol levels.
 Chemically, monounsaturated fatty acids are made up of a carbon chain, which contains
one carbon-to-carbon double bond.
 This double bond occurs after the ninth carbon, and thus can also be referred to as an
omega-9 fatty acid.
Polyunsaturated Fatty Acids
 Polyunsaturated fatty acids are found mainly in vegetable oils such as canola, corn,
safflower and sunflower oils.
 They are liquid at room temperature.
 Studies indicate that polyunsaturated fatty acids have been associated with lowering
LDL (bad) cholesterol levels.
 Polyunsaturates such as linoleic acid and alpha-linolenic acid cannot be produced by the
body and therefore must be obtained in our diet. They are called essential fatty acids
and are necessary for such functions as cell-building and hormone-production.
 A polyunsaturated fatty acid carbon chain contains two or more carbon-to-carbon
double bonds. If the double bond starts after the third carbon it is classified as an mega3 fatty acid; if it starts after the sixth carbon, it is an omega-6 fatty acid and so on.
Trans Fatty Acids
 Trans fatty acids occur naturally in some animal products, such as butter and milk.
 They have also been found in some processed foods and when vegetable oils are
processed into margarines or shortening through hydrogenation. Hydrogenation is a
process used in the production of some margarines and shortenings. The process
involves adding hydrogen to oil to make it spreadable at room temperature.
 Research suggests hydrogenated products may have similar effects as saturated fatty
acids on raising LDL (bad) cholesterol and may also lower high density lipoprotein—HDL
(good) cholesterol.
Triglycerides
Fats and oils in foods are mostly triglycerides (a classification of fats). This means that three
fatty acid chains are attached to a glycerol, a three-carbon alcohol. Removing a fatty acid from
a triglyceride forms a diglyceride; removing two forms a monoglyceride. This occurs during
digestion. Triglycerides are responsible for not only the flavor and mouth-feel of fats, but also
provide our body with energy, energy storage and transporting of fat-soluble vitamins A, D, E
and K.
Phospholipids
Phospholipids are another classification of fats or lipids. They are present in very small amounts
in food and act chiefly as emulsifying agents. Phospholipids are found in buttermilk and eggs.
Phospholipids, like triglycerides, are built around a glycerol. However, at least one fatty acid is
replaced with a compound containing phosphorus. Lecithin, a phospholipid, is used as an
emulsifier in processed foods such as salad dressings. Emulsifiers such as lecithin suspend fats
in liquid ingredients.
Sterols
Sterols are another class of fats. They are found in animal foods- meat, fish, poultry, egg yolks
and milk fat. Cholesterol and vitamin D are the best known sterols. Chemically, sterols are very
different from fatty acids, phospholipids and triglycerides. They do not contain any fatty acids
or glycerol. They are made up of carbon rings, but because they do not dissolve in water, they
are classified as a fat.
Cholesterol
Cholesterol is important in producing hormones, such as estrogen and testosterone and bile, a
key emulsifier needed for digestion. Blood (serum) cholesterol and dietary cholesterol are two
types of cholesterol. Dietary cholesterol or the cholesterol found in foods comes only from
animal sources such as egg yolks, organ meats and full-fat diary products. Blood cholesterol is a
white, waxy substance that occurs naturally in our body. It is manufactured by the liver and is
necessary for our bodies to function properly. Problems can arise if the level of cholesterol in
the blood is too high and begins building up on the artery walls.
Blood cholesterol can be further broken down into high density lipoprotein- HDL (good)
cholesterol and low density lipoprotein- LDL (bad) cholesterol. Excess levels of LDL (bad)
cholesterol build up on the inside of the arteries blocking the blood flow and increasing the risk
of heart disease.
Fat-intake in our diets can play an important role in controlling LDL levels. Foods high in
saturated fatty acids and/or dietary cholesterol, such as processed meats, full-fat dairy
products, egg yolks and organ meats may increase LDL levels.
HDL cholesterol gathers up excess cholesterol in the blood and carries it back to the liver to be
reprocessed or excreted. It may also remove some of the blood cholesterol deposited on the
artery walls.
Dietary Recommendations
Though cholesterol is found in food, it is not an essential nutrient for humans. Our bodies
manufacture most of the cholesterol we need. Unfortunately, the relationship between dietary
intake of cholesterol and blood cholesterol levels is not simple. Researchers theorize that only
20 to 30 percent of the population is genetically hypersensitive to dietary cholesterol. In other
words, their blood cholesterol increases when they eat foods high in cholesterol. However,
health professionals recommend consuming no more than 300 milligrams of cholesterol per
day. Dietary changes can have an effect on blood cholesterol level. As mentioned, saturated
fatty acids have been shown to stimulate production of LDL cholesterol. That is why limiting
your cholesterol intake but not your saturated fatty acids can still result in high blood
cholesterol levels.
Overall, reducing fat intake and choosing those foods that are low in saturated fatty acids and
cholesterol is beneficial. Today’s dietary guidelines suggest only 30 percent of our total daily
calories come from fats with saturated fatty acids comprising no more than ten percent of the
calories.
Canola oil has the best fatty acid ration of all the fats of the market. It contains the lowest level
of saturated fatty acids and is high in both monounsaturated fatty acids (which may lower LDL
(bad) cholesterol levels) and polyunsaturated fatty acids, which are essential in human diets.
Too Little Fat
If you don’t consume enough essential fatty acids, your skin will become flaky and itchy.
Canada’s Food Guide recommends 2 to 3 tablespoons of unsaturated fat each day, which is
enough to satisfy our body’s need, even on a low-fat diet.
Too Much Fat
A diet high in fat, especially saturated fatty acids, trans fatty acids and cholesterol may increase
the low density lipoprotein- LDL (bad) cholesterol in the blood. High levels of LDL cholesterol in
the blood build-up on artery walls. This build up is known as plaque. If enough plaque build up
occurs, the artery will become completely blocked, leading to a heart attack or stroke.
Other diseases that may be associated with a high-fat diet include obesity, certain cancers and
diabetes.
Heart Disease Assessing Risk
Controllable Risk Factors
 High blood cholesterol levels can lead to the build up of plaque on the arteries.
 Smoking has been linked to narrowing arteries because it makes part of the blood
(platelets) stickier, which in turn attracts cholesterol deposits to the artery walls.
Smokers are three to four times more likely to develop heart disease than non-smokers.
 High blood pressure puts extra strain on the heart and arteries.
 Stress increases the heart rate and may cause headaches and muscle tension.
 Obesity puts extra strain on the heart. Overweight people often have high cholesterol,
diabetes, high blood pressure and lead inactive lives. All are factors associated with
heart disease.
 Lack of exercise reduces overall fitness, which can lead to increased weight and high
blood pressure.
 A high sodium diet can contribute to high blood pressure. Therefore, sodium products
that include salt (sodium chloride) should be used in moderation.
 Alcohol is high in calories but low in nutrients. Alcohol contributes to obesity and may
cause high triglycerides in the blood. Excessive intake can lead to addiction.
 Diet, weight control and regular exercise are important in controlling diabetes and heart
disease.
Uncontrollable Risk Factors
 Family medical history of heart disease may increase the chance of heart disease or
stroke.
 Diabetics are three or four times more likely to suffer heart attacks than non-diabetics.
 Gender- men are two to three times more vulnerable to heart attacks than women,
especially in earlier years. However, once women reach menopause, they become as
susceptible to heart disease as men.
 Age- risk of heart disease increases with age. Nearly 55 percent of heart attack victims
are 65 or older.
Reduce Your Fat Intake:

Choose foods which are lower in saturated fatty acids and/or help to lower cholesterol
levels:

vegetables

fruits

dried peas and beans

barley

oats

vegetable oils like canola, which has the lowest level of saturated fatty acids of
all oils on the market today and is cholesterol-free

Change your eating habits:

limit intake of doughnuts, croissants, butter rolls and biscuits

use oil-based salad dressings on salads

use soft-tub margarine instead of butter or hard-block margarine

drink skim or 1% milk

eat low-fat cheeses such as skim milk mozzarella, Edam, Gouda, Brie,
Camembert, cottage cheese

use jam, jelly or marmalade on bread or toast and skip the butter or margarine

eat whole grain bread, rolls and cereals

eat lean cuts of meat

eat yogurt, ice-milk, sorbets or popsicles as substitutes for ice cream

Modify your food preparation habits:

substitute low-fat yogurt, blender whipped low-fat cottage cheese or buttermilk
for recipes calling for sour cream, mayonnaise or cream cheese

use a non-stick pan for cooking

use a canola oil spray for frying

steam, boil or bake vegetables

season vegetables with herbs and spices

use canola oil in baked products instead of solid fats or hydrogenated
shortenings

trim fat from meat before and after cooking

roast, bake or broil meat, poultry and fish so fat drains away as food cooks

remove skin from poultry before cooking

chill meat or poultry broth until the fat solidifies and skim before using

replace whole milk with skim milk in puddings, soups and baked products

reduce portions of fats used in cooking and at the table
Food Labels Are Great Fat-Finders
Are “unsweetened” or cholesterol-free products better for you? Can “calorie-reduced” or “fatreduced” products help achieve healthy eating goals? What is the difference between high and
very high sources of dietary fibre? And, what does “light” mean anyway?
A recent study of Canadian grocery shoppers conducted by the National Institute of Nutrition of
Canada (NIN), showed that nutrition is very important to consumers. However, consumers
often do not understand label information that can help them make healthy food choices.
Fortunately, it isn’t hard as it seems at first glance. Once you know the basics, reading food
labels will help you to make low-fat food choices. Here are the basics:
The label says…
Fat and Cholesterol
What it means
Cholesterol-free
No more than 3 mg of cholesterol per 100
g, and must meet the standard for “low in
saturated fatty acids” (see below)
Fat-free
No more than 0.1 g of fat per 100 g
Low in cholesterol
No more than 20 mg cholesterol per
serving, and must meet the standard for
“low in saturated fatty acids” (see below)
Low in fat
No more than 3 g of fat per serving
Low in saturated fatty acids
No more than 2 g saturated fatty acids per
serving; no more than 15% of total energy
derived from saturated fatty acids
“Lean” ground beef
Maximum 17% fat content
“Medium” ground beef
Maximum 23% fat content
“Regular” ground beef
Maximum 30% fat content
Calories and Sugar
Calorie free
Contains no more than 1 calorie per 100 g
Calorie-reduced
Contains 50% fewer calories than the
regular (not calorie-reduced) version
Low-calorie
Contains 15 calories or less per serving
Low in sugar
No more than 2 g of sugar per serving
No sugar added/unsweetened
May contain naturally present sugar, but
has no sugar added
Sugar-free
No more than 0.25 g of sugar per 100 g; no
more than 1 calorie per 100 g
Source of energy
Contains at least 100 calories per serving
Fibre
Source dietary fibre
At least 2 g of fibre per serving
High source of dietary fibre
At least 4 g of fibre per serving
Very high source of dietary fibre
At least 6 g of fibre per serving
Salt and Sodium
Low sodium
Contains 50% less sodium than the regular
product; no more than 40 mg of sodium
per 100 g; no salt added
No added salt/unsalted
No salt added, and none of the ingredients
contains a large quantity of salt.
Salt-free/sodium-free
Contains no more than 5 mg of sodium per
100 g
MICROWAVE POPCORN
Insert Actual Graphic???
Nutrition Facts
Serving size 24 g (3 cups popped)
Energy 82 Cal / 343 kJ
Protein 2.3 g
Fat 3.1 g
Saturated 0.3 g
+ Trans 0 g
Polyunsaturated 2.0 g
Monounsaturated 0.8 g
Cholesterol 0 mg
Carbohydrate 12 g
Sodium 70 mg
Potassium 83 mg
*Cholesterol-Free
INGREDIENTS: Popping Corn, NonHydrogenated Canola Oil, Salt,
Natural Flavor.
Tips for Making Sense of Food Labeling







Product ingredients are listed according to descending order of weight. The ingredient
present in the largest quantity is listed first and the last ingredient in the smallest
quantity. If one of the first ingredients listed is a fat or oil, then the product may be high
in fat. Palm, palm kernel, coconut oils, butterfat and tallow are sources of saturated
fatty acids to watch out for on labels.
Check the serving size. Typically, serving size or suggested serving size is on the product
label. The nutrient profile is based on the serving size.
Watch for invisible fat in foods.
Carefully read labels when the food claims to be ‘cholesterol-free’ or ‘lite.’ Cholesterolfree doesn’t necessarily mean fat-free. ‘Lite’ may refer to color, texture or taste. Check
the label to see if it is lower in calories and fat.
Fat content of dairy products is listed as MF (milk fat) or BF (butterfat).
Check levels of each fatty acid: saturated, polyunsaturated and monounsaturated.
Does the product contain trans fat? Health Canada now requires that labels display the
level of this harmful fat. Also, look for ‘hydrogenated’ or ‘partially-hydrogenated’
ingredients. Hydrogenation is a process used in the production of some margarines and
shortenings that produces trans fatty acids. Select products with no or the lowest level
of trans fats.



An easy way to determine how many grams of fat you may eat during the day is to
divide your weight (in pounds) by two. If you weigh 130 pounds, then your fat goal for
the day is about 65 grams. (Your maximum daily fat intake can be used only if you are
within a recommended weight for your height.) The decision to eat a serving of
microwave popcorn depends on whether you want to “spend” 3.1 grams of your 65
gram allotment.
The fat content provided on the nutrition label can be used to determine the
percentage of calories provided by fat in the food product. Note that the total number
of grams of fat in a single serving of microwave popcorn is 3.1 g. We can use the
conversion factor (1 gram of fat = 9 calories) to determine that about 34% of the
calories in a serving of microwave popcorn come from fat. Here’s how the calculation
was made:
3.1 g x 9 calories per gram of fat = 27.9 calories from fat
27.9 calories from fat divided by 82 calories per serving = 0.34 x 100 = 34%
The following are steps you can take to figure how many grams of fat you are allowed
daily to keep your intake under 30 percent of total calories: Begin by setting your caloric
goal for the day. In this example, let’s decide that your caloric goal is 1,800 calories for
the day. First, multiply 1,800 by 30 percent.
1,800 total calories x 0.30 from fat = 540 calories from fat
Next, convert your fat calories to grams of fat, using the conversion factor 1 gram of fat
= 9 calories. We can determine the number of grams of fat in this fashion:
540 calories x 1 g of fat = 540 = 60 grams of fat
9 calories
9
In this example, you may eat 60 grams of fat during the day and keep the total amount
eaten under 30 percent of total calories, if your caloric goal in 1,800 calories.
Teacher’s Activity Guide
The following activities are designed to strengthen the students’ understanding of the subject
matter. Choose activities you feel would work best with your class.
A. Lecture on Types of Fats
Objectives
The student will be able to:
Describe the role of fat in the diet
Define fats, oils, fatty acids, triglycerides, phospholipids, sterols and cholesterol
Determine the difference between invisible and visible fats
Determine the difference between fats and oils
List the different types of fatty acids
Materials/Equipment
Powerpoints 1 to 11
LCD projector
Background information on fats (Note: The background information could be used as
handouts or lecture notes.)
Procedure
Using powerpoints and lecture notes, go through fat definitions.
Students can take notes or use background information as handouts.
Evaluation
With partners, have students create ways to remember the definitions.
Ideas for remembering – diagrams, games, or play Jeopardy (Activity F).
B. Dietary Recommendations for Fat
Objectives
The student will be able to:
List the dietary recommendations for fat.
Discuss the implications of consuming too little fat/too much fat.
List the risk factors associated with heart disease.
Discuss the media messages surrounding fat.
List ways to reduce fat intake.
Materials
Background information
Powerpoints 12 to 15
LCD projector
Magazines
Scissors, glue, and tape
Poster board, colored paper
Procedure
Have students brainstorm dietary recommendations for fat from their notes, media,
personal experience. Add ones they miss.
Use powerpoints to discuss the implications of consuming too much/too little fat.
Use powerpoints to list the risk factors associated with heart disease.
Brainstorm media messages about fat, cholesterol …
Brainstorm ways to reduce fat intake.
Break class into four groups and assign each group with one of the following topics:
(1) Dietary Recommendations for Fat
(2) Consuming Too much Fat/Too Little Fat
(3) Risk Factors for Heart Disease
(4) Media Messages About Fat
Have groups develop a poster or bulletin board display incorporating background
information with visual reinforcements.
Evaluation
Have groups present their creations, discussing their components.
C. Fat Fight Quiz: This activity could be used as an opening or
summary activity for this unit.
Objectives
The student will be able to:
Determine if he/she eats too much fat.
Materials/Equipment
One quiz per student. Note: “Thinning out the Fat” article could be photocopied on
the back of the Quiz for extra reading.
Procedure
Ask each student to complete the quiz.
Evaluation
After students have scored their quizzes, discuss choosing low-fat foods and food
preparation methods to reduce fat intake.
Thinning Out the Fat
Should fat be avoided at all costs? Of course not. Some fat is needed to stay healthy. But, too
much fat increases the risk of developing some health problems including diabetes, obesity,
certain cancers and heart disease. Our total daily fat intake must be considered for health.
Why has fat been given a bad reputation? Fatty foods are often high calorie foods. When these
foods are eaten in excess, calories add up quickly and excess calories can mean excess weight.
Fat has a bad name because of its association with blood cholesterol levels. Eating too many
foods with high saturated fat content has been shown to increase blood cholesterol levels.
Foods high in saturated fat are mainly of animal origin and include meats, cream, butter, whole
milk, and full-fat cheeses. Hydrogenated fats found in foods such as baked goods, shortening,
peanut butter and hard margarines are also saturated fat. So, reducing your total fat intake and
using less saturated fat can help to prevent heart disease.
Here are some ways you can “thin out” the fat without depriving yourself of taste:
1. Taper down the fat. Do it gradually so your body can adjust to the change in fat intake.
Use products containing less fat. Put 2% milk in your coffee or tea instead of cream or
coffee whitener.
2. Watch your meat intake. Meat is a great source of protein, iron, and zinc, but it is also a
source of saturated fatty acids. Eating smaller portions (100g/ 3oz.) can bring intake
closer to Canada’s Food Guide for Healthy Eating guidelines. Also, choosing leaner cuts,
trimming off the fat, removing the skin and using low fat preparation methods (broiling,
baking, roasting) will help keep meat, and not fat, a healthy part of your diet.
3. Be a label reader. Ingredients are listed in decreasing order of weight. If fat appears
near the beginning of the list, then the food may be high in fat. Palm and coconut oils,
partially hydrogenated oils, shortening, and tallow are saturated fatty acid sources to
watch for on labels.
4. Shed the spread. Do you load on the margarine thinking it’s healthful? Using margarine
instead of butter does not reduce the calories or fat, so spread it lightly. Some
margarines contain hydrogenated fat. Choose soft tub margarines since they are
generally less hydrogenated than the block variety.
5. Practice pleasure-maximization. Having a higher fat food or meal once in a while won’t
hurt you. Hot dogs, luncheon meats, and cheesecake can me enjoyed occasionally
without ruining healthy eating habits. Just be sure that when you eat these foods, its
worth it to you in terms of taste and satisfaction.
Overall, healthy eating means less fat, period. The type of fat you eat is less important. Eating
less saturated fatty acids and fewer hydrogenated food products will generally affect blood
cholesterol levels much more than the cholesterol present in the foods you eat. Be “Fat-Wise,”
choose lower and better fat alternatives more often.
D. Visible and Invisible Fats
Objectives:
The student will be able to:
Identify visible and invisible fat in foods.
Materials/Equipment:
Four pieces of paper towel
Piece of cheese, muffin
Slice of tomato
Slice of apple
Procedure:
Lay out four pieces of paper towel. Gently rub a piece of cheese against one
piece of paper or let the cheese sit on the paper for ten minutes.
Let a muffin sit on a piece of paper towel for ten minutes.
Gently rub a slice of apple against a piece of paper towel or let it sit on the paper
for ten minutes.
Let a slice of tomato sit on a piece of paper towel for ten minutes. Remove each
of the food items from the paper towel and let the papers dry.
The food items could be set up ahead of time at a work station, the food taken
off at the beginning of the work period so that the paper is dry for observation
by the end of the period.
Evaluation:
Ask students to observe the dry papers and determine which papers have grease
stains. The papers with grease stains show which foods have fat in them.
Hold the paper up to the light, some of the light will shine through. A fat spot
will not dry up and disappear, no matter how long you wait.
This equipment could be used with any food to see if it has invisible fat.
E. Comparison of Dietary Fat
Objectives:
The student will be able to:
Determine that each type of fat/oil is made up of different fatty acids.
Determine that there are healthier choices when comparing fats/oils.
Apply knowledge of fatty acids.
Materials/Equipment:
Comparison of Dietary Fat Powerpoint Slide
Comparison of Dietary Fat Question Sheet (Note: “Jumping on the Trans Train”
runs onto the back of the question sheet.)
Procedure:
Display Comparison of Dietary Fat slide. Hand out Comparison of Dietary Fat
activity sheet.
Students can then answer questions either as individuals, small groups or as a
teacher-led activity.
Evaluation:
Activity sheets could be handed in for marking or could be gone through as a
group.
COMPARISON OF DIETARY FATS ACTIVITY SHEET
Each fat and oil is made up of different fatty acids. Answer the following questions using the
Dietary Fat Comparison Chart.
1. (A) Which oil has the lowest percentage of saturated fatty acids?
is the dietary recommendation for saturated fatty acids?
(B) What
2. (A) Which three oils have the highest percentage of monounsaturated fatty acids? (B)
List three points about monounsaturated fatty acids.
3. (A) Which oil has the highest percentage of alpha-linolenic acid?
(B) Which
has the highest percentage of linoleic acid?
(C) Polyunsaturated fatty
acids are referred to as the essential fatty acids. Why?
4. (A) Which fats in the chart contain cholesterol?
and define two types of blood cholesterol.
contain cholesterol?
recommendation for cholesterol?
(B) Name
(C) Do plant-based oils
(D) What is the dietary
5. (A) Which two plant-based oils have the highest level of saturated fatty acids?
JUMPING ON THE TRANS TRAIN
Recent news reports about trans fatty acids in processed foods stressed the negative effects of
these fats. Some headlines, and even Conan O’Brian of NBC’s The Late Show, suggested that
butter might be less risky in terms of heart health.
Here’s a summary of the research findings and some practical answers to the question: “What
type of fat should I be eating?”
Trans fatty acids occur naturally in some animal products OR form when vegetable oils are
turned into shortenings through the processes called “hydrogenation” and “partial
hydrogenation.” Research over the past years points to a link between raised blood cholesterol
levels and diets high in trans fatty acids. The most recent studies found that trans fatty acids
appear to have a similar or greater capacity to raise blood cholesterol than do saturated fatty
acids.
According to Dr. Walter Willett of Harvard Medical School, the major sources of trans fatty
acids in our diets are certain margarines, cookies, crackers, cakes and deep-fried foods. These
foods also tend to be higher in total fat or saturated fatty acids. So, the rise in blood cholesterol
levels is not solely due to the trans fatty acids.
The renewed interest in trans fatty acids began in 1990 when Drs. Mensink and Katan from the
Netherlands found increased blood cholesterol levels in people fed a diet containing very high
levels of trans fatty acids. In these people, the LDL (bad) blood cholesterol was raised and the
HDL (good) blood cholesterol was lowered. Dr. Bruce Holub of the University of Guelph and Dr.
Scott Grundy at the University of Texas Southwestern Medical Center agreed that these results
suggest that trans fatty acids might have a double-barreled harmful effect. However, this Dutch
study fed people much higher amounts of trans fatty acids than normally eaten. In fact, we
tend to eat only 2 to 3 percent of our daily calories as this type of fat.
Other researchers studied the effects of lower intakes of trans fatty acids. Dr. Joseph Judd from
the Beltsville Human Nutrition Research Center in Maryland found that trans fatty acids raised
blood cholesterol similarly to saturated fatty acids. Dr. Walter Willett’s most recent comments
showed that he felt that trans fatty acids may increase blood cholesterol to a greater degree
than saturated fatty acids. In both cases, the researchers concluded that trans fatty acids could
be implicated in heart disease. At this point in time, most large manufacturers have made the
change from a hydrogenated fat to products such as high stability canola oils, or canola/palm oil
shortenings.
Does this mean a switch from margarine to butter? No. In terms of heart health, margarine
seems to be preferred by most health experts. Soft tub margarine contains about 39 percent
combined saturated fatty acids and trans fatty acids, while butter contains 71 percent.
What information should you look for on a food label? Check the ingredient list for
hydrogenated or partially hydrogenated vegetable oils. Vegetable shortening means the same
thing. These words indicate that trans fatty acids are present in the food. Current Health
Canada labeling regulations require that the amount of trans fatty acids be declared on the
packaging. To compare fat profiles of different products, add the saturated fatty acids and the
trans fatty acids together. The product with the lowest total for the same serving size is the
better choice.
So, how can you best avoid trans fatty acids? Eat less fat. Avoid deep-fried foods and choose
lower-fat food products. Read product nutrition labels. And remember—headlines don’t tell the
whole story!
Comparison of Dietary Fats Activity Sheet ANSWERS
1. (A) Canola Oil—7%
(B)
Reduce saturated fatty acid levels (only 10 percent of total daily calories from saturated
fats per day).
2. (A) Safflower Oil—77%, Olive Oil—75% and Canola Oil—61%.
Liquid at room temperature.
mainly in vegetable oils.
indicate that monounsaturates may lower LDL (bad) cholesterol
(B)
Found
Studies
levels.
3. (A) Flaxseed Oil—57%
(B)
Sunflower Oil—71%
(C)
Polyunsaturates such as linoleic acid and alpha-linolenic acid cannot be produced by the
body and therefore must be obtained from our diet. They are called essential fatty acids
and are necessary for such functions as cell-building and hormone production.
4. (A) Lard—12 mg/Tbsp.
Butterfat—33 mg/Tbsp.
(B) High Density Lipoprotein- HDL (good) cholesterol gathers up excess cholesterol in the
blood and carries it back to the liver to be reprocessed or excreted. It may also remove
some of the cholesterol deposited on the artery wall.
Low Density Lipoprotein- LDL (bad) cholesterol. Excess levels of LDL build up on the
inside of the arteries blocking the blood flow and increasing the risk of heart disease and
stroke.
(C) No.
(D) Reduce cholesterol intake (no more than 300 milligrams per day).
5. Coconut Oil—91%
Palm Oil—51%
F. JUST-like Jeopardy
Objectives:
The student will be able to:
Review definitions and concepts taught in this unit.
Materials/Equipment:
Chalkboard
Bells (one per team)
Game
Procedure:
On the chalkboard, write five titles:
Fat
Types of Fat
Cholesterol
Dietary Recommendations
Potpourri
Questions & Answers provided in separate document.
Photocopy questions back to back. Cut out game cards and assemble them at
the chalk board under the titles, question side down.
Divide the class into teams and explain the rules.
To extend the game, have students develop further questions.
RULES:
1. The team who answers a question correctly scores the number of points on
the back of the question.
2. The team who answers a question correctly picks the next question (i.e. “Fats
for 300”).
3. After a question is asked, the group who rings its bell first has the first
opportunity to answer. If the answer is incorrect, the remaining teams race to
ring their bells.
If no
team answers correctly, then the team who chose the question selects another
question.
4. The team with the most points wins.
Evaluation:
The teacher can observe the students’ level of understanding and any students
or areas that require additional attention.
QUESTIONS TO JUST-LIKE JEOPARDY GAME:
TYPES OF FAT
$100
$200
$300
$400
$500
What are
saturated fatty
acids?
What are trans
fatty acids?
What are
saturated fatty
acids?
What are
polyunsaturated
fatty acids?
What are monounsaturated fatty
acids?
CHOLESTEROL
FAT
What is bile?
What is a
lipid?
What are animal
sources?
What is blood
cholesterol?
What is heart
disease?
What is HDL or
good (healthy)
cholesterol?
What is
energy?
What are
visible
fats?
What are
fat-soluble
vitamins?
What are
nuts
and/or
seeds?
DIETARY
RECOMMENDATIONS
POTPOURRI
What is cholesterol?
What is a basic
vinaigrette?
What is high blood
cholesterol level?
What is stable?
What are
vegetables?
What are canola
oil and canola
meal?
What is 30%?
What are
Canada and Oil?
What is canola oil?
What is a
moisturizer?
G. Food Labels are Great Fat Finders
Objectives:
The student will be able to:
Understand labeling terms.
Determine fat content of food products.
Determine how many grams of fat they would consume to make 30% of their
daily caloric intake.
Apply mathematical equations to determine percentage of calories provided by
fat in a food product.
Materials/Equipment:
Background information.
Powerpoint slide 16
Food products with nutritional labeling
Food Labels are Great Fat Finders Activity Sheet (Note: Photocopy “Label
Confusion” article on back for extra reading.)
Procedure:
Using background information and powerpoint slides, discuss how to read food
labels.
Provide students with food products with nutritional labeling and the Food
Labels are Great Fat Finders Activity Sheet. Use food products to answer
questions on activity sheet.
Evaluation:
Activity sheet could be handed in for marking or could be gone through as a
group exercise.
FOOD LABELS MAKE GREAT FAT FINDERS ACTIVITY SHEET
Choose a food product from the ones provided. Answer the following questions using your
chosen food product.
1. (a) Describe your food product. Include name, total amount in the container, any
nutritional claims (“lite”, cholesterol-free), serving suggestions or cooking instructions.
(b) List ingredients. What is the largest quantity ingredient in this product? Smallest
quantity?
(c) Are there any fats/oils listed in the ingredients? Please list.
(d) What are the levels of each fatty acid in your food product?
(e) What is the total fat content of a serving of your food product?
(f) Does your food product contain trans fatty acids? How can you tell?
(g) What is the percentage of calories from fat in your food product?
2. Based on your weight, how many grams of fat should you eat during a day?
3. Set a goal for the number of calories you should eat based on your age, gender and
activity level. (Use Canada’s Food Guide to help you set your goal.) Using this goal,
determine how many grams of fat you could eat if fat made up 30% of your caloric intake.
LABEL CONFUSION
Most packaged foods carry some nutrition information on their labels. Learning to understand
various nutrition claims is an important step in making healthy food choices. Ingredients are
listed by weight with the heaviest ingredient first. Begin by looking at the list of ingredients.
Compare the following labels:
Minestrone Soup: Water, red kidney beans, white beans, lima beans, carrots, potatoes, celery,
cabbage, green beans, tomato paste, chickpeas, macaroni, salt, canola oil, onions, olive oil,
garlic, spices.
Creamy Mushroom Soup: Water, mushrooms, vegetable oil, cream, butter, flour, potato starch,
salt, onions, garlic.
Minestrone soup contains both canola and olive oil, but the ingredients appear close to the end
of the list. You can assume that the soup is not too high in fat. On the other hand, creamy
mushroom soup has vegetable oil, butter and cream as the third, fourth and fifth ingredients.
This means fat is a major ingredient in the product. Knowing the various names of fat is also
important. Fat may be listed as lard, tallow, cream, shortening, coconut or palm oil, or as monoor diglycerides. Also, look at the number of times fat shows up on the ingredient list. When
taken together, small amounts of several kinds of fat may make the product high in fat.
What about “light” products? A food labeled as “light” or “lite” must be at least 23 percent
lower in the nutrient being promoted than the “regular” product. Be aware, however, that
while some light products are lower in calories per serving, they may still be high in fat. Take
light cream cheese for example. It is lower in fat and calories than a regular cream cheese but
even the “light” variety cannot be considered a low fat item. Also, check the serving size when
comparing light products to regular items. Sometimes you find the “light” product is lighter
because the serving size is smaller. If you continue to eat your usual portion, you may as well
stick with the regular variety.
Are “no cholesterol” or “cholesterol-free” products good choices? People believe cholesterol is
unhealthy and they try to avoid it. What they many not understand is that cholesterol, by itself,
is not bad. It is the total fat content of the diet that is harmful. Advertising may increase the
confusion. French fries may not be prepared with cholesterol, but turning a plain potato into
French fries certainly increases the fat. It is the amount of fat we eat and not the amount of
cholesterol that is the real problem for heart disease and weight control.
(Source: Public Health Nutritionists of Saskatchewan)