November 2010
Protein’s Contribution to the
Reduction of Chronic Disease Risk
Adapted from Spotlight on Nutrition Issues
with permission from Dairy Farmers of Canada
•
•
•
Introduction
Chronic diseases are the major
Key Messages
cause of death and disability
Emerging scientific evidence
worldwide.1 In Canada, chronic
suggests that the optimal
diseases are estimated to account for
dietary protein intake is greater
approximately 89% of all deaths.1
than the Recommended
The economic impact of premature
Dietary Allowance (RDA),
deaths due to heart disease, stroke
particularly for the prevention
of chronic disease.
and diabetes is substantial: in
2005 it was estimated that Canada
Replacing dietary
lost approximately $500 million
carbohydrate with protein,
in national income as a result of
within the Acceptable
premature deaths from chronic
Macronutrient Distribution
Range (AMDR), may decrease diseases.2 However, at least 80% of
the risk of cardiovascular
these premature deaths could be
disease by improving blood
prevented by modifying individual
lipid profiles and reducing
lifestyle behaviors to include a
blood pressure.
healthy, balanced diet and regular
Protein consumption, within
physical activity.1 These are costthe AMDR, has been shown
effective interventions that could
to increase glucose control
slow the spiralling cost of chronic
and insulin sensitivity and also
disease in Canada.
contributes to body weight
regulation.
•
Milk and milk products are
good sources of high-quality
protein and have their own
unique components that may
play a role in the prevention
and management of chronic
disease.
moreaboutmilk.com
Scientific research suggests that
moderate consumption of protein,
within the Acceptable Macronutrient
Distribution Range (AMDR), can
provide nutritional and metabolic
advantages that may prevent and
manage chronic diseases. The
chronic diseases discussed in this
issue of Nutrition File™ for Health
Educators are cardiovascular
disease, type 2 diabetes and obesity.
Emerging evidence suggests
that adequate consumption of
milk protein reduces the risk of
these common chronic diseases.
Additionally, dairy products are
important contributors to higherprotein diets, which further prevent
and manage chronic disease risk.
Did you know?
Milk Proteins
Cow’s milk represents a unique source of
nutrients that can act both independently
and synergistically with one another. Milk
contains two types of protein: whey (20%)
and casein (80%). Both are high-quality
proteins, according to science-based
rating scales, and both contain all
essential amino acids in amounts
sufficient to support the multiple roles of
protein in the body.3,4
According to the Protein DigestibilityCorrected Amino Acid Score (a method
of measuring protein quality based on
availability of essential amino acids as
well as digestibility), milk provides higherquality protein than beef, soy or wheat.5
Because of its high quality, cow’s milk
protein is used as a standard reference
protein to evaluate the nutritive value of
food proteins.6 Individual milk proteins
have been shown to exhibit a wide range
of beneficial functions that may play a
role in the prevention and management
of chronic disease.
Cardiovascular Disease
The term cardiovascular disease
describes a cluster of diseases
of the circulatory system; it
is currently the leading cause
of death in adult Canadians.14
Ischemic heart disease, or heart
attack, is the most common type
of cardiovascular disease and
affects both men and women.15
The majority of cases of
cardiovascular disease stem from
modifiable risk factors, including
lack of physical activity, poor
diet, smoking, high blood
cholesterol, hypertension and,
potentially, stress.15
Healthy eating, which includes
sufficient dietary protein
consumption, assists in the
reduction of cardiovascular
disease risk. In particular, some
components of milk proteins
have been shown to reduce
blood pressure, which can
contribute to lowering total
estimated cardiovascular risk.16
poultry and dairy products,
produces beneficial metabolic
effects. Increasing protein intake
can reduce simple carbohydrate
consumption and contribute to
weight loss.
The Evidence: Dietary Protein
and Cardiovascular Disease
An abnormal blood lipid profile
consists of elevated levels of
low-density lipoprotein (LDL)
cholesterol, low levels of highdensity lipoprotein (HDL)
cholesterol, and high levels of
triglycerides, a type of fat in
blood.14
In one study, the comparison
of three types of diets – high
carbohydrate, high unsaturated
fat and high protein – revealed
favourable changes from baseline
lipoproteins in all but the highcarbohydrate diet.18 However, the
high-protein diet also significantly
reduced the triglyceride
concentration compared with
the other two diets.18 The authors
proposed that this further
reduction in triglycerides by the
high-protein diet reveals that
protein possesses a triglyceridelowering effect, beyond the result
of its replacing carbohydrates in
the diet.18
The Canadian Cardiovascular
Society recommends a diet
reduced in simple sugars and
refined carbohydrates for the
prevention of cardiovascular
disease in adults.17 Subsequent
evidence suggests that replacing
simple carbohydrates with
other macronutrients, such
as protein from lean meats,
Dietary Reference Intakes
The Dietary Reference Intakes are nutrient reference guidelines that aim to ensure that Canadians consume
healthy, balanced diets.7 These guidelines consist of standard recommendations, including the Recommended
Dietary Allowance (RDA) and the Acceptable Macronutrient Distribution Range (AMDR).7 The RDA is an estimate
of the minimum amount of a nutrient required to prevent deficiency in most healthy people in a specific life stage
and gender group.7 The RDA for protein for adults is 0.8 grams of protein per kilogram of body weight per day.8
Some researchers have suggested that the RDA, while useful for micronutrients, is not suitable for
macronutrients.9,10 Emerging scientific evidence suggests that the optimal dietary protein intake is greater than the
RDA, particularly for the prevention of chronic disease. This evidence further indicates that this standard may be
inappropriate for the Canadian population.11,12
In contrast, the AMDR, expressed as a percentage of total energy intake, is a range of intakes determined to
meet nutrient requirements that is also associated with a reduced risk of chronic disease.8 Proponents of the latter
are encouraging clinicians to abandon the RDA – the minimum daily requirement – and adopt the AMDR as the
standard for macronutrient consumption.9,10
The AMDR for protein is 10% to 35% of total daily energy intake.8 Currently, Canadians consume an average of
17% of their daily calories from protein, or approximately 85 grams of protein per day.13 According to the AMDR,
Canadians can safely increase their protein intake to as much as 35% of daily calories, or approximately 175
grams of protein per day for an average man or 130 grams per day for an average woman.
2
Type 2 Diabetes Mellitus
Type 2 diabetes is a chronic
disease that develops in
stages. The onset is defined as
insulin resistance, which is the
decreased ability of insulin to
stimulate muscle to clear glucose
from the blood.27 In the later
stages of diabetes, the pancreas
loses the ability to secrete extra
insulin in response to elevated
levels of blood glucose.27
Additional research supports
the improvement of individuals’
blood lipid profiles with a
moderate increase in protein
intake, within the recommended
AMDR, by decreasing
triglyceride concentration,19–22
increasing HDL cholesterol22 and
reducing LDL cholesterol.19,22
Finally, further scientific
evidence suggests that a
moderate increase in protein
consumption, within the AMDR,
results in a decreased risk of
coronary heart disease18 and
reduced estimated 10-year
coronary heart disease risk.2
Hypertension, another
modifiable risk factor, plays a
role in cardiovascular disease
prevention and management.
The longitudinal study,
Coronary Artery Risk
Development In young Adults
(CARDIA), concluded that
protein intake was inversely
associated with average
blood pressure in multiethnic
groups during seven years of
follow-up.23 A meta-analysis
confirms this association.24
Emerging evidence suggests
that the protein component of
milk has hypotensive effects.16
Currently, more than three
million Canadians are living
with diabetes and this number is
expected to grow to 3.7 million
by 2020.28 The number of people
diagnosed with type 2 diabetes
is increasing as a result of the
aging of the population, rising
rates of obesity and decreasing
levels of physical activity.28 It
is estimated that by 2020, the
annual cost of diabetes to the
Canadian health care system will
be approximately $16.9 billion.28
Specifically, milk protein–
derived peptides can inhibit
angiotensin-1 converting enzyme
(ACE) activity, a mechanism
similar to the action of many
antihypertensive medications.16
Furthermore, the addition of
whey protein (a protein found in
dairy products) to the diet
has also demonstrated significant
blood pressure–decreasing
effects when compared to
glucose controls.25,26 Additionally,
whey protein has produced
significant improvements in
inflammatory markers and
individual vascular function.26
Therefore, milk, as a whole food,
has the potential to decrease
blood pressure and should
be considered an essential
component of the treatment of
hypertension.16 The August 2010
issue of Nutrition File™ for Health
Educators, “Dietary Factors in
the Prevention and Management
of Hypertension,” described
the role of dairy products in
the Dietary Approaches to Stop
Hypertension (DASH) Diet, a
highly advocated strategy for the
prevention and management of
hypertension.
Lifestyle modifications,
including adequate physical
activity, a balanced diet and
achieving or maintaining a
healthy body weight, can
prevent or delay the onset of
type 2 diabetes and help those
already diagnosed manage
the disease. For example, a
protein-rich diet can reduce
hyperglycemia after meals,
improve overall glucose
control and decrease glycated
hemoglobin (a blood marker
used to identify the average
plasma glucose over the previous
three months). Additionally,
there is considerable evidence
that adequate consumption of
milk products is associated with
a reduced risk of developing
3
type 2 diabetes.29,30 Several
components of milk products
may be responsible for reducing
this risk. Recent evidence
supports the role of milk protein
in improving glycemic control
and contributing to weight
management.
The Evidence: Dietary Protein
and Type 2 Diabetes Mellitus
Achieving optimal glycemic
control is fundamental to the
management of diabetes. Both
fasting and post-prandial plasma
glucose levels correlate with
the risk of complications and
contribute to the measured
glycated hemoglobin value.31
Emerging evidence indicates
that a short-term increase in
dietary protein consumption
dramatically lowers glycated
hemoglobin concentration,
which indicates improved
glycemic control.32,33 However,
longer-term studies are required
to understand whether an
increase in dietary protein
consumption also improves
long-term glucose control and
decreases the glycated
hemoglobin value.
The 2008 Canadian Diabetes
Association Clinical Practice
Guidelines recommend a diet
reduced in simple sugars and
refined carbohydrates, as do the
Canadian Cardiovascular Society
guidelines.17,34 The guidelines
do not provide suggestions as
to which macronutrients should
replace refined carbohydrates,
but there are only two options:
protein and fat. Recent studies
have compared the effects of
replacing simple carbohydrates
Q&A
Q: Does high dietary protein consumption have a negative effect
on bone health?
A: Despite this widely held belief, research strongly suggests that individuals
with high protein intakes – up to approximately 2 grams per kilogram of body
weight – actually have better bone quality when calcium intake is adequate
(specifically 1000 to 1200 milligrams per day).42 This is true throughout the life
cycle: adequate protein intake is associated with high bone mineral density
in teenage girls and in premenopausal women,43 and high dietary protein
consumption has been correlated with reduced risk of hip fracture in both
elderly men and women.44
The misconception that high dietary protein intakes lead to poor bone health
came from early studies that identified a correlation between increased protein
intake and increased urinary calcium excretion.45,46 For example, the acid-ash
hypothesis theorizes that the consumption of protein increases the acid load
of the diet and brings about the release of calcium from the skeleton, leading
to increased urine calcium and eventually, osteoporosis.47
However, current research does not support the principles of the acid-ash
hypothesis and suggests that dietary protein actually increases intestinal
absorption of calcium. Therefore, excretion of calcium in the urine may result
from increased gastrointestinal calcium absorption that results in adequate
calcium balance.45-47 Research completed to date shows negative calcium
balance depends on dietary calcium intake, not protein intake.48 Moreover,
Heaney and Layman suggest that optimal protein intakes for bone health are
likely higher than currently recommended intakes, particularly in the elderly.42
Research strongly supports adequate amounts of both protein and calcium,
two key components of milk, for healthy bones.
Q: Are higher-protein diets
considered safe?
A: The Dietary Reference Intakes report
no identifiable health risks associated with
protein consumption up to 35% of total
energy intake in healthy individuals.8,49
However, caution is advised for
individuals with renal disease as protein
consumption at the higher end of the
AMDR is contraindicated in such cases.50
Renal function decreases with age;
therefore, assessment of renal function
is recommended before older individuals
adopt a higher-protein diet.51
Q: Should I recommend protein
supplements to my clients to
enhance their protein intakes?
A: People can easily meet their protein
requirements by consuming whole foods such as milk products, eggs, nuts,
legumes, lean meats, fish and poultry. Consuming protein supplements
may cause adverse effects such as diarrhea and bloating.52 A balanced diet,
including whole, protein-rich foods, is a healthier, less expensive and sufficient
way to meet individual protein requirements.53
4
with protein-rich foods in
the diets of individuals with
type 2 diabetes and found less
variation in plasma glucose
and plasma insulin with this
altered macronutrient intake.32–34
Additionally, strong evidence
has established that dietary
protein intake improves postprandial glycemic control
in healthy35–38 and insulinresistant individuals20 as well
as in individuals with type 2
diabetes.33,39
Milk proteins are associated
with reduced post-prandial
glycemia.38 Specific mechanisms
for these metabolic outcomes
are still being determined,
but evidence suggests that
the ingestion of food protein
results in a significant increase
in plasma insulin.40 Therefore,
the replacement of refined
carbohydrates with protein-rich
foods will result in a reduced
glucose response, not only
because of the increased insulin
response from the protein
source, but also owing to the
decreased ingestion of simple
carbohydrates.
Food proteins differ in their
capacity to stimulate insulin
release.41 In one study,
whey protein, a fraction of
milk protein, demonstrated
insulinotropic properties above
those demonstrated by other
food sources, such as cod and
wheat gluten.41 These results
indicate that consumption of
milk protein may stimulate
insulin activity and, therefore,
that regularly consuming milk
with meals may reduce postprandial glycemia.
to the accretion of lean muscle
mass.47,58-60 Lower-fat milk
has proven to be an effective
drink to support favourable
body composition outcomes
during resistance training by
stimulating muscle protein
synthesis in men62,63 and
promoting lean-mass gain and
fat-mass loss in women.64
Weight Management: A Key to
Preventing Chronic Disease
Excess body weight is a major
risk factor for chronic diseases,
such as cardiovascular disease,
type 2 diabetes and metabolic
syndrome.15,17,56,57 Maintaining
optimal energy balance, which
includes both physical activity
and healthy eating, is a key
prevention strategy.15,17,41,56,57
Adequate protein consumption
may enhance the benefits of
resistance-based physical
activity, such as weight lifting,
by promoting accretion of lean
muscle mass47,58-60. It also plays
an important role in healthy
eating through its effects on
appetite.
Weight loss is also often
associated with bone loss. In
one study, consumption of a
high-protein diet and three daily
servings of milk and alternatives
during a period of weight loss
attenuated participants’ bone
mineral loss.65 Encouraging the
consumption of milk products
after periods of physical
activity and during weight
loss endeavours promotes the
maintenance of lean muscle
mass and bone mass, thereby
promoting weight loss primarily
of adipose tissue.61,65
Physical Activity
It is important for health
professionals to motivate clients
to engage in regular exercise.
Ideally, adults should aim for
30 to 60 minutes of moderate
physical activity most days
of the week, incorporating a
mixture of endurance, flexibility
and weight-bearing activities.61
Regular exercise is beneficial not
only for weight loss, but also
to assist with favourable body
composition changes, including
the development
and maintenance of
muscle mass.47
Healthy Eating
The 2006 Canadian clinical
practice guidelines for the
management and prevention
of obesity conclude that a
moderate increase in protein
Additionally, the
consumption of
protein, including
milk protein,
immediately after
resistance exercise
may assist with
protein synthesis
and contribute
5
consumption, within the AMDR,
may be advantageous for
weight loss.66 Dietary protein
plays a role in body weight
regulation, partially through its
effects on appetite. Protein as a
macronutrient has proven to be
significantly superior to both fat
and carbohydrate in producing
satiety.67 Additionally, milk
protein has been demonstrated
to be more effective than soy
protein at decreasing hunger.50,68
In Your Practice
Nutrition therapy, including
optimizing intake of high-quality
protein, can play an integral role
in reducing the risk of chronic
disease. Protein-rich foods are
typically found in the Meat
and Alternatives, and Milk
and Alternatives food groups
of Canada’s Food Guide and
include lean meats, fish, poultry,
eggs, cheese, yogurt, legumes
and nuts (see Table 1).62,74
Timing of protein intake
is important; scientific
research suggests that protein
consumption at breakfast
decreases hunger and appetite
throughout the rest of the
day.69,70 According to one
study, the consumption of
protein-rich snacks, such as
cheese, should not promote
weight gain because energy
intake appears to be regulated
during subsequent meals.71
In summary, milk protein’s
ability to reduce hunger72,73 and
increase satiety50,68 can produce
substantial decreases in caloric
intake, resulting in successful
weight management.
Milk in particular is an excellent
source of high-quality complete
protein in a nutrient-rich
package.5 In fact, given the
nutrient density of milk, which
contains protein, calcium and
vitamins D, B12 and A, it is
Table 1. Protein-Rich Foods75
Food Group
Food
Protein
Content
(g)
Meat
and
Alternatives
Beef sirloin steak, 75 g
Tofu, firm, raw, 75 g
Pork tenderloin, 75 g
Chicken, skinless breast, 75 g
Tuna, canned light, 75 g
Eggs, whole cooked, 2 large
Kidney beans, boiled, 175 ml (3/4 cup)
Lentils, boiled, 175 ml (3/4 cup)
Almonds, 60 ml (1/4 cup)
26
21
21
20
19
13
12
13
8
Milk
and
Alternatives
Cottage cheese, 125 ml (1/2 cup)
Cheddar cheese, 50 g (1½ oz)
Milk, 250 ml (1 cup)
Yogurt, 175 ml (3/4 cup)
15
12
8
8
Grain Products
Whole-wheat pasta, cooked, 125 ml (1/2 cup)
Whole-wheat bread, 1 slice (35 g)
Brown rice, cooked, 125 ml (1/2 cup)
Oatmeal, prepared, 175 ml (3/4 cup)
4
3
3
3
Vegetables
and
Fruit
Potato, with skin, cooked, 125 mL (1/2 cup)
Broccoli, cooked, 125 mL (1/2 cup)
Butternut squash, cooked, 125 mL (1/2 cup)
Banana, raw, 1 medium
5
2
1
1
Did you know?
It is commonly believed that
recreational athletes have higher
protein requirements than average
Canadians; however, studies show
no benefit to exercise or sport
performance with consumption
of dietary protein in excess of
the Acceptable Macronutrient
Distribution Range.54 Furthermore,
adequate dietary protein
consumption can be achieved with
a balanced diet, without the use of
protein supplements.53-55
surprising that Canadians’
average consumption of milk
products is below
recommendations13,60; this
food source of protein should
be particularly encouraged.
The evidence-based AMDR
recommends 10% to 35% of
caloric intake from protein.8
Currently, Canadians consume
approximately 17% of their
daily energy from protein
sources.13,60 Therefore,
Canadians can safely increase
their daily consumption of
dietary protein; in fact, most
Canadians could double their
protein intake and still be
safely within recommended
guidelines.
6
A diet reduced in refined
carbohydrates has been
recommended for individuals
diagnosed with type 2 diabetes,
obesity or cardiovascular
disease.17,34,66 A wealth of research
has demonstrated that replacing
carbohydrates in the diet with
protein may have a number
of beneficial health effects.
Consumption of approximately
25 to 30 grams of dietary protein
at meals maximally stimulates
protein synthesis.48
Encouraging your clients to
consume a serving of milk
and alternatives at each meal
will help them meet the daily
servings from this food group
recommended by Eating Well
with Canada’s Food Guide and
will also ensure they are well
on their way to consuming an
adequate amount of protein at
each meal.
Conclusion
Evidence has shown that in
addition to reducing the risk
of obesity, adequate protein
consumption, as part of a
balanced diet, may also help
prevent and manage other
chronic diseases, such as
cardiovascular disease and
diabetes. In particular, milk
products are protein-rich foods
that may promote optimal body
composition and help prevent
and manage chronic diseases.
Healthy eating patterns can
include a wide range of protein
intakes – from 10% to 35% of
total energy for adults.8 Health
professionals should encourage
two to four daily servings from
the Milk and Alternatives food
group, depending on the client’s
age. In addition, promoting
consumption of other proteinrich foods, such as lean meats,
beans, fish, eggs and poultry to
replace simple sugars and refined
carbohydrates in accordance with
the 2009 Canadian Cardiovascular
Society guidelines, the 2008
Canadian Diabetes Association
Practice Guidelines and Eating
Well with Canada’s Food Guide is
advised.17,33,62 These relevant and
timely recommendations may
help reduce the risk of common
chronic diseases in the Canadian
population.
ThisissueofNutrition File™ for Health
EducatorswasadaptedfromSpotlight
on Nutrition Issueswithpermission
fromDairyFarmersofCanada.The
articlewaswrittenbyVeronicaStreeter,
MAN,RDandVanessaNagy,andwas
reviewedbyDr.StuartPhillips,PhD.
Foracompletelistofreferences,visit
moreaboutmilk.com/educators.aspx
Auserfriendlyfactsheethasbeen
includedwiththisnewsletter.
The team of Alberta Milk registered dietitians are:
Lee Finell, MHSA, RD
Colinda Hunter, RD
Debbie Pietsch, RD
Cindy Thorvaldson, MSc, RD
Jaclyn Chute, RD
Nutrition File™ is a free quarterly research newsletter for health
professionals, funded by the dairy producers of Alberta. If you are a new
reader and would like to add your name to our mailing list,
please contact Alberta Milk at:
Phone: 1-877-361-1231
E-mail: nutrition@albertamilk.com
7
Protein: Key to a Heart-Healthy Diet
Protein is an important part of your everyday diet that can help lower your risk of heart disease. Replacing
some of the carbohydrate in your diet with protein can help lower your cholesterol and control your blood
pressure.
Help your heart! Ideas to get you going:
1. Spread out your protein intake over the entire day.
• Start your day with a protein-rich breakfast.
Try these protein-packed ideas:
"" Whole-grain toast
with peanut butter
"" Oatmeal with nuts
"" Cottage cheese
with fruit
• Have a glass of milk at
breakfast – it’s an easy
way to add a good source of protein.
2. Make sure you get enough – have protein rich foods at each meal.
• Try some of these tasty protein-rich meal
ideas:
"" Ham and Canadian Swiss cheese sandwich on whole-grain bread
"" Grilled salmon fillet with brown rice and vegetables
"" Slice of vegetable lasagne with a glass of milk
3. Choose snacks that pack a protein punch.
• The following snacks all contain at least one protein-rich food:
"" Cut-up vegetables
and whole-wheat
pita with hummus
"" Yogurt with
almonds and fresh fruit
"" A bowl of whole-grain cereal with milk
4. Use Canada’s Food Guide to discover protein rich foods.
• You can find protein-rich foods in the Milk
and Alternatives and Meat and Alternatives
food groups.
2010 Alberta Milk
1-877-361-1231
• Enjoy two to three Food Guide servings of
Milk and Alternatives each day.
• Include two to three Food Guide servings of
Meat and Alternatives each day.
• You can order a free copy of Eating Well with
Canada’s Food Guide at healthcanada.gc.ca/
food guide.
5. Make heart-healthy choices.
• Choose leaner meats and lower-fat milk,
cheese and yogurt.
• Eat at least two Food Guide servings of fish
each week (1 serving = 75 grams, or 2 ½
ounces).
• Enjoy meatless meals more often by cooking
with high-protein meat alternatives such as
beans, lentils or tofu.
Did you know?
• Most Canadians eat carbohydrate-rich
foods at breakfast and lunch and eat
most of their protein at dinner.
• Many Canadians
do not get enough
milk products.
Milk is a good
source of
protein – and
the proteins
in milk play
an important role in
controlling blood pressure.
For more information on protein and nutrition,
find a registered dietitian in your area by visiting
dietitians.ca.
Permission granted to reproduce.
References
Nutrition File™ for Health Professionals - November 2010
Protein’s Contribution to the Reduction of Chronic Disease Risk
1.
World Health Organization. Facts related to chronic disease.
http://www.who.int/dietphysicalactivity/publications/facts/chronic/en. Accessed June 9, 2010.
2.
Haydon E et al. Chronic disease in Ontario and Canada: determinants, risk factors and prevention
priorities. Report prepared for the Ontario Chronic Disease Prevention Alliance and the Ontario
Public Health Association, 2005. http://www.ocdpa.on.ca/rpt_ChronicDiseaseOntario.htm.
Accessed May 25, 2010.
3.
Phillips SM et al. The role of milk- and soy-based protein in support of muscle protein
synthesis and muscle protein accretion in young and elderly persons. J Am Coll Nutr
2009;28(4):343–354.
4.
Bos C et al. Nutritional and physiological criteria in the assessment of milk protein quality for
humans. J Am Coll Nutr 2000;19(2):191S–205S.
5.
Schaafsma G. The Protein Digestibility-Corrected Amino Acid Score. J Nutr 2000;130:1865S–
1867S.
6.
Miller GD et al. Handbook of dairy foods and nutrition, 3rd ed. Boca Raton, FL: CRC Press, 2007.
7.
Barr SI. Introduction to Dietary Reference Intakes. Appl Physiol Nutr Metab 2006;31(1):61–65.
8.
Institute of Medicine. Dietary Reference Intakes for energy, carbohydrates, fibre, fat, fatty
acids, cholesterol, protein and amino acids (macronutrients). Washington, DC: National
Academy Press, 2005.
9.
Lomangino K. The RDA for protein: the minimum or optimal intake. Clin Nutr Insight
2008;34(10):4–5.
10.
Wolfe RR and Miller SL. The Recommended Dietary Allowance of protein: a misunderstood
concept. JAMA 2008;299:2891–2893.
11.
Millward DJ. Macronutrient intakes as determinants of dietary protein and amino acid adequacy.
J Nutr 2004;134:1588S–1596S.
12.
Layman DK. Dietary guidelines should reflect new understanding about adult protein needs. Nutr
Metab (Lond) 2009;6:12 doi:10.1186/1743-7075-6-12.
13.
Garriguet D. Overview of Canadians’ eating habits. Health Rep 2007;18(2):17–32.
http://www.statcan.gc.ca/pub/82-003-x/2006004/article/ habit/9609-eng.pdf. Accessed June 17,
2010.
14.
Public Health Agency of Canada. Cardiovascular disease, 2009. http://www.phac-aspc.gc.ca/cdmc/cvd-mcv/index-eng.php. Accessed May 27, 2010.
15.
Public Health Agency of Canada. Minimizing the risk of cardiovascular disease, 2009.
http://www.phac-aspc.gc.ca/cd-mc/cvd-mcv/risk-risqueseng.php. Accessed May 27, 2010.
16.
FitzGerald RJ et al. Hypotensive peptides from milk proteins. J Nutr 2004;134:980S–988S.
17.
Genest J et al. Canadian Cardiovascular Society/Canadian guidelines for the diagnosis and
treatment of dyslipidemia and prevention of cardiovascular disease in adults – 2009
recommendations. Can J Cardiol 2009;25(10):567–579.
18.
Furtado JD et al. Effect of protein, unsaturated fat, and carbohydrate intakes on plasma
apolipoprotein B and VLDL and LDL containing apolipoprotein C-III: results from the
OmniHeart Trial. Am J Clin Nutr 2008;87:1623–1630.
19.
Appel LJ et al. Effects of protein, monounsaturated fat, and carbohydrate intake on blood
pressure and serum lipids: results of the OmniHeart Randomized Trial. JAMA 2005;294:2455–
2464.
20.
Farnsworth E et al. Effect of a high-protein, energy-restricted diet on body composition, glycemic
control, and lipid concentrations in overweight and obese hyperinsulinemic men and women. Am
J Clin Nutr 2003;78:31–39.
21.
Noakes N et al. Effect of an energy-restricted, high-protein, low-fat diet relative to a
conventional high-carbohydrate, low-fat diet on weight loss, body composition, nutritional
status, and markers of cardiovascular health in obese women. Am J Clin Nutr 2005;81:1298–
1306.
22.
Layman DK et al. A moderate-protein diet produces sustained weight loss and long-term
changes in body composition and blood lipids in obese adults. J Nutr 2009;139:514–521.
23.
Liu K et al. Blood pressure in young blacks and whites: relevance of obesity and lifestyle factors
in determining differences: the CARDIA Study. Circulation 1996;93:60–66.
24.
Liu L et al. Epidemiological evidence of the association between dietary protein intake and blood
pressure: a meta-analysis of published data. Hypertens Res 2002;25:689–695.
25.
Luhovyy BL et al. Whey proteins in the regulation of food intake and satiety. J Am Coll Nutr
2007;26(6):704S–712S.
26.
Pal S and Ellis V. The chronic effects of whey proteins on blood pressure, vascular function, and
inflammatory markers in overweight individuals. Obesity 2009;doi:10.1038/oby.2009.397.
27.
Canadian Diabetes Association. Clinical practice guidelines for the prevention and
management of diabetes in Canada: definition, classification and diagnosis of diabetes and
other dysglycemic categories. Can J Diabetes 2008;32(Suppl 1):S10-S13.
28.
Canadian Diabetes Association. The prevalence and cost of diabetes
http://www.diabetes.ca/documents/about-diabetes/PrevalanceandCost_09.pdf. Accessed May 27,
2010.
29.
Pereira MA et al. Dairy consumption, obesity, and the insulin resistance syndrome in young
adults: the CARDIA Study. JAMA 2002;287:2081–2089.
30.
Choi HK et al. Dairy consumption and risk of type 2 diabetes mellitus in men. Arch Intern Med
2005;165:997–1003.
31.
Canadian Diabetes Association. Clinical practice guidelines for the prevention and management
of diabetes in Canada: targets for glycemic control. Can J Diabetes 2008;32(Suppl 1):S29–S31.
32.
Boden G et al. Effect of a low-carbohydrate diet on appetite, blood glucose levels, and insulin
resistance in obese patients with type 2 diabetes. Ann Intern Med 2005;142:403–411.
33.
Gannon MC and Nuttall FQ. Effect of a high-protein, low-carbohydrate diet on blood glucose
control in people with type 2 diabetes. Diabetes 2004;53(9):2375–2382.
34.
Canadian Diabetes Association. Clinical practice guidelines for the prevention and
management of diabetes in Canada: nutrition therapy. Can J Diabetes 2008;32(Suppl 1):S40–
S45.
35.
Ratliff J et al. Consuming eggs for breakfast influences plasma glucose and ghrelin, while
reducing energy intake during the next 24 hours in adult men. Nutr Res 2010;30:96–103.
36.
Frid AH et al. Effect of whey on blood glucose and insulin responses to composite breakfast and
lunch meals in type 2 diabetic subjects. Am J Clin Nutr 2005;82:69–75.
37.
Akhavan T et al. Effect of premeal consumption of whey protein and its hydrolysate on food
intake and postmeal glycemia and insulin responses in young adults. Am J Clin Nutr
2010;91:966–975.
38.
Petersen BL et al. Whey protein supplement decreases post-prandial glycemia. Nutr J 2009;8(47):
doi:10.1186/1475-2891-8-47.
39.
Solerte SB et al. Metabolic effects of orally administered amino acid mixture in elderly
subjects with poorly controlled type 2 diabetes mellitus. Am J Cardiol 2004;93(Suppl):23A–29A.
40.
Floyd JC et al. Insulin secretion in response to protein ingestion. J Clin Invest 1966;45(9):1479–
1486.
41.
Nilsson M et al. Glycemia and insulinemia in healthy subjects after lactose equivalent meals of
milk and other food proteins: the role of plasma amino acids and incretins. Am J Clin Nutr
2004;80:1246–1253.
42.
Heaney RP and Layman DK. Amount and type of protein influences bone health. Am J Clin Nutr
2008;87(Suppl):1567S–1570S.
43.
Beasley JM et al. Is protein intake associated with bone mineral density in young women? Am J
Clin Nutr 2010;91(5):1311–1316.
44.
Misra D et al. Does dietary protein reduce hip fracture risk in elders? The Framingham Osteoporosis
Study. Osteoporos Int 2010;May 5 [Epub ahead of print].
45.
Kerstetter JE et al. Dietary protein, calcium metabolism, and skeletal homeostasis revisited. Am J
Clin Nutr 2003;78(3 Suppl):584S–592S.
46.
Ginty F. Dietary protein and bone health. Proc Nutr Soc 2003;62(4):867–876.
47.
Fenton TR et al. Meta-analysis of the effect of the acid-ash hypothesis of osteoporosis on calcium
balance. J Bone Miner Res 2009;24:1835–1840.
48.
Heaney PP. Dietary protein and phosphorus do not affect calcium absorption. Am J Clin Nutr
2000;72(3):758–761.
49.
Eisenstein J et al. High protein weight loss diets: are they safe and do they work? A review of the
experimental and epidemiologic data. Nutr Rev 2002;60:189–200.
50.
Halton TL and Hu FB. The effects of high protein diets on thermogenesis, satiety and weight loss:
a critical review. J Am Coll Nutr 2004;23:373–385.
51.
Paddon-Jones D et al. Role of dietary protein in the sarcopenia of aging. Am J Clin Nutr
2008;87(Suppl):1562S–1566S.
52.
Wolfe RR. Protein supplements and exercise. Am J Clin Nutr 2000;72(2):551S–557S.
53.
Maughan RJ et al. Dietary supplements. J Sports Sci 2004;22:95–113.
54.
Zello G. Dietary Reference Intakes for the macronutrients and energy: considerations for physical
activity. Appl Physiol Nutr Metab 2006;31:74–79.
55.
Rodriguez NR et al. American Dietetic Association, Dietitians of Canada, American College of
Sports Medicine. Position of the American Dietetic Association, Dietitians of Canada, and the
American College of Sports Medicine: nutrition and athletic performance. J Am Diet Assoc
2009;109(3):509–527.
56.
Klein S et al. Weight management through lifestyle modification for the prevention and
management of type 2 diabetes: rationale and strategies. A statement of the American Diabetes
Association, the North American Association for the Study of Obesity, and the American Society
for Clinical Nutrition. Am J Clin Nutr 2004;80:257–263.
57.
Canadian Diabetes Association. Clinical Practice Guidelines for the Prevention and
Management of Diabetes in Canada: introduction. Can J Diabetes 2008;32(Supp 1):S1–S4.
58.
Phillips SM. Protein requirements and supplementation in strength sports. Nutrition
2004;20:689–695.
59.
Phillips SM et al. Dietary protein to support anabolism with resistance exercise in young men. J
Am Coll Nutr 2005;24(2):134S–139S.
60.
Elliot TA et al. Milk ingestion stimulates net muscle protein synthesis following resistance
exercise. Med Sci Sports Exerc 2006;38:667–674.
61.
Public Health Agency of Canada. Handbook for Canada’s physical activity guide to healthy
active living. http://www.phac-aspc.gc.ca/hp-ps/hl-mvs/ pag-gap/pdf/handbook-eng.pdf.
Accessed June 13, 2010.
62.
Hartman JW et al. Consumption of fat-free fluid milk after resistance exercise promotes greater
lean mass accretion than does consumption of soy or carbohydrate in young, novice, male
weightlifters. Am J Clin Nutr 2007;86(2):373–381.
63.
Wilkinson SB et al. Consumption of fluid skim milk promotes greater muscle protein
accretion after resistance exercise than does consumption of an isonitrogenous and isoenergetic
soy protein beverage. Am J Clin Nutr 2007;85(4):1031–1040.
64.
Josse AR et al. Body composition and strength changes in women with milk and resistance
exercise. Med Sci Sports Exerc 2010;42(6):1122–1130.
65.
Thorpe MP et al. A diet high in protein, dairy and calcium attenuates bone loss over twelve
months of weight loss and maintenance relative to a conventional high-carbohydrate diet in
adults. J Nutr 2008;138:1096–1100.
66.
Lau D et al. Canadian clinical practice guidelines on the management and prevention of obesity in
adults and children [summary]. CMAJ 2006;176(8):S1–S13.
67.
Paddon-Jones D et al. Protein, weight management, and satiety. Am J Clin Nutr
2008;87(Suppl):1558S–1561S.
68.
Veldhors MA et al. Dose-dependent satiating effect of whey relative to casein or soy. Physiol
Behav 2009;96:675–682.
69.
Leidy HJ and Racki EM. The addition of a protein-rich breakfast and its effects on acute appetite
control and food intake in ‘breakfast-skipping’ adolescents. Int J Obes 2010;34(7):1125–1133.
70.
Leidy HJ et al. Increased dietary protein consumed at breakfast leads to an initial and sustained
feeling of fullness during energy restriction compared to other meal times. Br J Nutr
2009;101:798–803.
71.
Potier M et al. A high-protein, moderate-energy, regular cheesy snack is energetically
compensated in human subjects. Br J Nutr 2009;102:625–631.
72.
Apolzan JW et al. Inadequate dietary protein increases hunger and desire to eat in younger and
older men. J Nutr 2007;137:1478–1482.
73.
Weigle DS et al. A high-protein diet induces sustained reductions in appetite, ad libitum
caloric intake, and body weight despite compensatory changes in diurnal plasma leptin and
ghrelin concentrations. Am J Clin Nutr 2005;82:41–48.
74.
Health Canada. Eating well with Canada’s food guide: a resource for educators and
communicators, 2007. http://www.hc-sc.gc.ca/fn-an/pubs/res-educat/res-educat-eng.php. Accessed
June 17, 2010.
75.
Health Canada. Canadian nutrient file, 2007. http://webprod.hc-sc.gc.ca/cnf-fce/startdebuter.do?lang=eng. Accessed June 28, 2010.