A Newsletter of the United Dairy Industry of Michigan
2013, No. 2
Nutrition Reports
Spotlight on Dairy Protein’s Health Benefits
Got Protein? Dairy Foods Provide High-Quality Protein Naturally
In recent years, protein has achieved
“super nutrient” status. This has resulted
from accumulating research suggesting an
array of health benefits associated with
consuming more protein at meals spread
throughout the day. Protein – a major
structural component of all cells in the
body – functions as enzymes, transport
carriers, and hormones. Research indicates
that increasing intake of high-quality
protein is associated with beneficial effects
on muscle development and maintenance,
weight management, and chronic diseases
such as sarcopenia (age-related loss of
skeletal muscle), osteoporosis, and type 2
diabetes.
To reap these suggested health
benefits, many Americans are seeking
protein-rich foods. According to the
International Food Information Council
Foundation’s 2013 Food & Health Survey
(http://www.foodinsight.org), 63% of
Americans consider protein when making
a decision about buying packaged food or
beverages, up from 56% in 2012.
The current Recommended Dietary
Allowance (RDA) for protein is 0.8 g/
kg body weight/day (0.36 g/lb) for those
aged 19 and older, which amounts to
about 55 g/day for men (154 lb) and 45
g/day for women (125 lb). The RDA is
based on the minimal amount of good
quality protein to prevent a deficiency,
as opposed to promoting optimal health.
The Institute of Medicine has established
an Acceptable Macronutrient Distribution
The United Dairy Industry
of Michigan is the umbrella
organization for Dairy Council
of Michigan and the American
Dairy Association of Michigan.
These non-profit organizations
provide nutrition education
services and dairy product
promotion.
Range (AMDR) for protein of 10 to 35%
of calories for adults or about 50 to 175 g
of protein for a 150 lb person consuming
about 2,000 calories/day. Emerging
research indicates that many Americans –
weight-conscious persons, aging adults,
and physically active individuals – could
benefit from a protein intake higher than
the current RDA but within the AMDR.
Milk, flavored milk, cheese, cottage
cheese, yogurt, and Greek yogurt are
naturally good to excellent sources of
high-quality protein. High-quality proteins
not only contain all of the essential amino
acids (building blocks of protein) that
cannot be made by the body, but also are
easily digested. Major milk proteins are
casein (~80%) and whey proteins (~20%).
Consuming 3 cups of fat-free or
low-fat milk and dairy products (cheese,
yogurt) a day, as recommended by the
2010 Dietary Guidelines for Americans
for those aged 9 years and over, can
help meet protein needs. One cup of
cow’s milk or yogurt contains 8 to 10 g
of protein and an equivalent serving (1½
oz) of Cheddar cheese has 9 to 11 g of
protein, the amount depending on the
specific food product. The protein content
is higher for a serving of Greek yogurt
than regular yogurt and for cottage cheese
than Cheddar cheese. Be aware that not
all “milks” are the same when it comes to
providing protein. For example, almond
“milk” has only 1 g of protein per 8 oz
serving compared to a similar size serving
of cow’s milk which contains 8 to 10 g of
protein.
Consuming dairy foods is a
convenient and nutritious
way to increase intake of
high-quality protein.
Recognizing consumers’ desire to boost
their protein intake, food manufacturers
are offering a wide variety of dairy and
non-dairy products with added dairy
protein ingredients. For information about
the protein content of specific dairy and
non-dairy foods, refer to the Nutrition
Facts panel on product labels.
McNeil, S. (Ed). Protein Summit 2007. Am. J. Clin. Nutr. 87(suppl):
1543s-1583s, 2008.
Layman, D.K. Dietary guidelines should reflect new understandings
about adult protein needs. Nutr. Metab. 6:12, 2009.
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Benefits of Higher Protein
Diets for Healthy Weight
Management
Compelling Reasons to
Increase Protein Intake in the
Golden Years
Dairy Protein’s Role in
Metabolic Health
Protein Education Resources
Higher Protein Diets Help
Protect Bones during Weight
Loss, Studies Suggest
Benefits of Higher Protein Diets for Healthy Weight Management
Diets rich in high-quality protein,
including dairy proteins, are gaining
scientific support as a strategy to help
achieve and maintain a healthy body
weight. The total amount, quality, and
distribution of protein intake throughout
the day matter.
A recent meta-analysis of controlled
trials reported in the American Journal
of Clinical Nutrition found that caloriereduced diets containing higher amounts
of protein (27% to 35% of calories) led
to greater weight and fat losses, while
preserving lean muscle mass, compared
to diets containing 16% to 21% of calories
as protein. A higher protein diet may also
help prevent a regain in weight.
Studies suggest diets
higher in protein, including
dairy foods that contain
high-quality protein, may
help manage weight and
control hunger.
Potential mechanisms for protein’s
beneficial effects on body weight include
its ability to increase satiety (a feeling of
fullness after or between meals) and dietinduced thermogenesis (energy needed
for metabolizing ingested nutrients), and
improve body composition (increase fat
loss and maintain or increase lean muscle
mass).
While reducing calories alone can
lead to weight loss, the weight lost often
includes both fat and lean muscle mass
(metabolically active tissue). Maintaining
lean muscle tissue not only is essential
for mobility and daily activities, but
also helps burn more calories, which is
important for preventing weight regain.
Dairy protein has been demonstrated
to be beneficial in weight management,
body composition, and satiety. A 16week study in 90 overweight or obese
premenopausal women showed that
following a daily exercise and reduced
calorie regimen with higher protein
(30% of calories) and increased dairy
protein intake (i.e., dairy provided half
of the protein) improved the quality of
weight loss. This higher protein/dairy
diet promoted more favorable body
composition changes (i.e., greater losses
of total and abdominal fat and a gain
in lean body mass) compared to diets
containing adequate protein (15% of
calories) with either adequate or low
dairy intake. Loss of abdominal fat is a
positive finding considering abdominal
fat’s link to adverse cardiovascular and
metabolic health.
Whey protein, a rich source of the
essential amino acid leucine, has received
attention because of its beneficial effect
on body composition during weight
reduction. Leucine stimulates muscle
protein synthesis, helping to spare lean
body mass during weight reduction. Also,
dairy proteins, casein and whey protein,
have been shown to increase satiety.
Americans typically consume the
majority of their protein intake in a single
meal at dinner. Because the body can
only use so much protein at a time, most
of this protein is wasted. For persons
on a higher protein diet, some experts
recommend consuming 20 to 30 g of
protein containing a minimum of 2.5 g
of leucine per meal (breakfast, lunch,
dinner) to fully stimulate muscle protein
synthesis and enhance satiety. Because
breakfast is typically lower in protein
than other meals, consuming increased
high-quality protein from foods such as
dairy at breakfast is considered to be a
good weight management strategy.
Dairy Research Institute, National Dairy Council. Scientific Status
Report: Higher protein diets and weight management. 2012. www.
nationaldairycouncil.org/Research/Pages/Scientific-Status-Reports.
aspx.
Wycherley, T.P., et al. Effects of energy-restricted high-protein, low-fat
compared with standard-protein, low-fat diets: a meta-analysis of
randomized controlled trials. Am. J. Clin. Nutr. 96: 1281-98, 2012.
Josse, A.R., et al. Increased consumption of dairy foods and protein
during diet- and exercise-induced weight loss promotes fat mass loss
and lean mass gain in overweight and obese premenopausal women. J.
Nutr. 141: 1626-1634, 2011.
Devkota, S., and D.K. Layman. Protein metabolic roles in treatment of
obesity. Curr. Opin. Clin. Nutr. Metab. Care 13: 403-407, 2010.
Protein Education Resources
Protein and whey protein Health Professional Education Kits for health
and wellness professionals to use with patients, clients, and the public can be
found by visiting www.nationaldairycouncil.org/EducationMaterials/.
• Protein. This kit includes information on the basics of protein,
the importance of consuming protein throughout the day, protein and
vegetarian meals, healthy aging, and exercise, and how dairy foods help
meet protein needs.
• Whey Protein. This kit includes frequently asked questions about
whey protein, educational resources including handouts, the latest
science behind the health benefits of whey protein, presentations (e.g.,
“How Protein Can Benefit the Everyday Fitness Enthusiast,” “Advances in
Successful Aging Strategies: Smart Nutrition, Effective Exercise,” and “The
Power Team: Combining Protein and Exercise for Effective Results”), and
recipes using whey protein.
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UNITED DAIRY INDUSTRY OF MICHIGAN • 1-800-241-MILK (6455)
Compelling Reasons to Increase Protein Intake in the Golden Years
Further, consuming
increased protein
intake evenly
throughout the
day, such as 20 to
30 g of high-quality
protein at each
meal (breakfast,
lunch, dinner),
can help preserve
muscle with aging.
As America’s older population is
growing and living longer, there’s
increased focus on maintaining a healthy,
physically active, independent lifestyle
in the golden years. Research suggests
that consuming a diet rich in high-quality
protein and engaging in regular resistance
exercise are key components of successful
aging.
The following are some reasons why
older adults should moderately increase
their intake of high-quality protein.
To help optimize muscle and
reduce risk of sarcopenia.
With aging, there’s progressive loss
of muscle mass which, if preventive
measures are not taken, can lead to
sarcopenia. Sarcopenia is associated with
reduced strength, increased frailty and
falls, functional impairment, and loss of
independence. Research indicates that
moderately increasing intake of highquality protein above the RDA of 0.8 g/
kg/day helps maintain or increase muscle
mass and reduce the risk of sarcopenia.
Milk-based
proteins have
been shown to
increase muscle mass in older adults. A
24-week clinical trial in frail older adults
participating in resistance-type exercise
showed significant gains in skeletal
muscle mass in those who consumed a
milk-based beverage containing 30 g of
protein (15 g of protein at breakfast and
lunch), whereas no change in muscle
mass occurred in those who consumed a
similar beverage containing no protein.
Low-fat and fat-free milk,
cheese, and yogurt are good
sources of high-quality
protein, and provide other
essential nutrients that may
help reduce older adults’
risk of sarcopenia and
osteoporosis.
Whey protein has been shown to
stimulate muscle protein synthesis in older
adults. A clinical trial using graded levels
of whey protein to increase protein intake
found that healthy older adults may need
twice as much protein as young adults
(40 g vs. 20 g) to maximize muscle protein
synthesis following resistance exercise.
To help support healthy bones
and reduce risk of osteoporosis.
Older adults are at risk of bone loss,
which can lead to osteoporosis (porous
bones) and increased susceptibility to
fractures. Despite the long-held belief that
higher protein intake has a detrimental
effect on bone health, research suggests
that higher dietary protein intake has a
beneficial impact on bones when calcium
and vitamin D are adequate.
Further, protein intake likely
contributes to bone health by its beneficial
effect on skeletal muscles which support
bones. An average protein intake of 1.0 to
1.2 g/kg/day is considered to be optimal
for skeletal muscle and bone health in
healthy older adults, according to recent
reviews.
Dairy Research Institute, National Dairy Council. Scientific Status
Report: Healthy Aging. 2012. www.nationaldairycouncil.org/Research/
Pages/Scientific-Status-Reports.aspx.
U.S. Dairy Export Council. Nutrition Monographs. Sarcopenia. May
2013. www.usdec.org (under Library).
Tieland, M., et al. Protein supplementation increases muscle mass
gain during prolonged resistance-type exercise training in frail elderly
people: a randomized, double-blind, placebo-controlled trial. J. Am.
Med. Dir. Assoc. 13: 713-719, 2012.
Yang, Y.L., et al. Resistance exercise enhances myofibrillar protein
synthesis with graded intakes of whey protein in older men. Br. J. Nutr.
108: 1780-1788, 2012.
Mithal, A., et al. Impact of nutrition on muscle mass, strength, and
performance in older adults. Osteop. Int. 24: 1555-1566, 2013.
Bauer, J., et al. Evidence-based recommendations for optimal dietary
protein intake in older people: a position paper from the PROT-AGE
study group. JAMDA, 2013.
Higher Protein Diets Help Protect Bones during Weight Loss, Suggest Studies
Bone loss can be a negative outcome
of cutting calories to lose weight.
However, recent clinical studies indicate
that consuming a higher protein diet
adequate in dairy foods or dairy nutrients
such as calcium helps preserve bone
during diet-induced weight loss.
According to a short-term clinical trial
in overweight/obese premenopausal
women who consumed a calorie-reduced
diet and exercised daily for 16 weeks,
biomarkers of bone formation increased
in those who consumed a diet higher
in protein and dairy foods than in the
women who consumed lower intakes. A
longer-term study in overweight/obese
postmenopausal women demonstrated
that consuming a weight-loss diet higher
in protein (24% of calories) and adequate
in calcium and vitamin D for a year
reduced bone loss at certain skeletal sites
and increased a marker of bone growth
compared to a similar diet lower in
protein (18% of calories).
Josse, A.R., et al. Diets higher in dairy foods and dietary protein
support bone health during diet- and exercise-induced weight loss
in overweight and obese premenopausal women. J. Clin. Endocrinol.
Metab. 97: 251-260, 2012.
Sukumar, D., et al. Areal and volumetric bone mineral density and
geometry at two levels of protein intake during caloric restriction: a
randomized, controlled trial. J. Bone Miner. Res. 26: 1339-1348, 2011.
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Dairy Protein’s Role in Metabolic Health
Dairy proteins (whey, casein)
and bioactive peptides derived from
milk proteins may help reduce the
risk of metabolic syndrome and its
complications, suggest recent reviews
of the science. Metabolic syndrome
occurs when an individual has three
of the following risk factors: central or
abdominal obesity, high blood pressure,
insulin resistance, glucose intolerance,
and/or an unhealthy blood lipid
profile. This syndrome, which affects
approximately one-third of U.S. adults,
increases the risk of developing type 2
diabetes and cardiovascular disease.
Reviews of animal and human studies
suggest that consuming whey protein
has beneficial effects on components
of metabolic syndrome. Whey protein
has been shown to help lower the risk
of obesity by reducing body weight,
improving body composition, and
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increasing satiety. It has also been shown
to decrease the risk of type 2 diabetes
by reducing blood glucose levels and
insulin resistance. Further, whey protein
may lessen the risk of cardiovascular
disease by favorably affecting blood lipid
profiles, and decreasing blood pressure,
arterial stiffness, systemic inflammation,
and oxidative stress. Bioactive peptides
derived from whey and casein may play
an important role in the prevention and
treatment of metabolic syndrome.
Pal, S., et al. The effects of whey protein on cardiometabolic risk
factors. Obes. Rev. Nov. 20, 2012 [Epub ahead of print].
Sousa, G.T.D., et al. Dietary whey protein lessens several risk factors for
metabolic diseases: a review. Lipids Health Dis. 11: 67, 2012.
Ricci-Cabello, I., et al. Possible role of milk-derived bioactive peptides
in the treatment and prevention of metabolic syndrome. Nutr. Rev. 70:
241-255, 2012.
McGregor, R.A., and S.D. Poppitt. Milk protein for improved metabolic
health: a review of the evidence. Nutr. Metab. 10: 46, 2013.
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