14

Journal of Exercise Physiologyonline
February 2018
Volume 21 Number 1

Editor-in-Chief
Official Research Journalof the American
Societyof
Tommy
Boone, PhD,
MBA
Review
Board
Exercise
Physiologists
Todd Astorino, PhD
1097-9751
JulienISSN
Baker,PhD
Steve Brock, PhD
Lance Dalleck, PhD
Eric Goulet, PhD
Robert Gotshall, PhD
Alexander Hutchison, PhD
M. Knight-Maloney, PhD
Len Kravitz, PhD
James Laskin, PhD
Yit Aun Lim, PhD
Lonnie Lowery, PhD
Derek Marks, PhD
Cristine Mermier, PhD
Robert Robergs, PhD
Chantal Vella, PhD
Dale Wagner, PhD
Frank Wyatt, PhD
Ben Zhou, PhD

Official Research Journalof the American Society of
Exercise Physiologists

ISSN 1097-9751

JEPonline
Case Reports on Well-Trained Bodybuilders: Two Years
on a High Protein Diet
Jose Antonio, Anya Ellerbroek
Department of Health and Human Performance, Nova Southeastern
University, Davie FL USA
ABSTRACT
Antonio J, Ellerbroek A. Case Reports on Well-Trained Bodybuilders:
Two Years on a High Protein Diet. JEPonline 2018;21(1):14-24. The
purpose of these case studies was to further assess 5 subjects who
consumed a high protein diet over an additional 12-month period (for a
total of 2 yrs) in order to determine if there were any adverse effects on
kidney or liver function. Five healthy resistance trained men (mean ±SD; age 30 ± 5 yrs; height 177.9 ± 5.5 cm) volunteered to consume ahigh protein diet (>2.2 g·kg-1·d-1) over another 1-yr period. They had
previously participated in a 1-yr high protein diet study. The subjects
came to the lab every 6 months to assess body composition via the
Bod Pod®. Body mass, fat mass, lean body mass (LBM), and body fat
percentage were ascertained. The subjects provided dietary selfreports via the MyFitnessPal® mobile app at least 3 times·wk-1. Noother instructions were given. All subjects were provided protein
powder so they could attain their protein intake goals. A comprehensive
metabolic panel was done in a fasted state at a local Quest Diagnostics
facility every 6 months. The findings indicate that 2 yrs of a high protein
diet in healthy resistance trained men had no effect on measures ofbody composition as well as liver or kidney function. Thus, there is noevidence to suggest that consuming a high protein diet over a 2-yr
period causes any harmful side effects.
Key Words: Body Composition, Bodybuilding, Diet

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INTRODUCTION
The long term effects (>1 yr) of high protein diets (>3 g·kg-1·d-1) on body composition andorgan function in resistance trained individuals has been largely understudied. The generalrecommendations for optimal protein intake for building and maintaining skeletal muscle
mass is 1.4 to 2.0 g·kg-1·d-1 according to the Position Stands of the International Society ofSports Nutrition (8,10). The first high protein study from our laboratory looked at bodycomposition and performance changes after consuming approximately 4.4 g·kg-1·d-1 for 8 wks
in highly trained individuals (4). The results showed no effects on body composition when
consuming a hyper-caloric diet while maintaining the same training regimen.
The follow-up study compared 2.2 g·kg-1·d-1 and 3.4 g·kg-1·d-1 for 8 wks following a periodized
training regimen. This investigation demonstrated that if a high protein is consumed in
combination with a change in one’s training program, there may be a decrement in fat mass.
Furthermore, there were no side effects from the high protein intake (1). This was followed by
a 1-yr trial (i.e., protein intake = 2.5 to 3.3 g·kg-1·d-1) in 12 highly trained individuals looking at
the effects on body composition, blood lipids, liver, and kidney function. The results showedno changes in body composition despite higher total energy intake, as well as no adverse
effects (3). However, it is unclear if maintaining a high protein diet for an additional year for a
total of 2 yrs will have any deleterious effects. Thus, the purpose of the case studies was tofurther assess five individuals on a high protein diet over another 1-yr period.
METHODS
Subjects
Five healthy resistance trained men volunteered to continue to consume a high protein diet(>2.2 g·kg-1·d-1) over another 1-yr period. They had previously consumed a high protein dietfor 1 yr. They were assigned to eat above 2.2 g·kg-1·d-1 with no upper limit for the 1-yr period.
The additional protein consumed by each subject was whey protein for 4 of the 5 subjects.
Whey protein was provided by Dymatize (Dymatize® ISO-100 with 25 g of protein, 1 g ofcarbohydrate, and 0 g of fat per serving of one scoop). One subject that was vegan wasprovided with Growing Naturals Pea powder (15 g of protein, 3 g of carbohydrate, and 1.5 g
per serving of one scoop). However, the subjects could choose to ingest any source ofprotein as long as they kept their intake above 2.2 g·kg-1·d-1. Subjects came to the university
Human Performance Laboratory every 6 months to assess body composition. A basic
metabolic panel was assessed at a local Quest Diagnostics facility. The university’s Human
Subjects Institutional Review Board in accordance with the Helsinki Declaration approved thisstudy, and a written informed consent was obtained prior to the subjects’ participation.
Procedures
Food Diary
Each subject kept a food diary for 3 d·wk-1 for 1 yr via a smartphone app (MyFitnessPal®)
equaling an additional 150 d (150 d had been logged with the previous study) of food logging
over the course of 12 months. The MyFitnessPal app is a database comprised of over 5
million foods that have been provided by users via entering data manually or by scanning thebar code on packaged goods. Thus, the data are primarily derived from food labels (i.e.,
nutrition facts panel) from the USDA National Nutrient database.

16

Body Composition
The subjects had their height and weight determined using a calibrated scale. They wereassessed for body composition via the Bod Pod® while wearing only tight fitting clothing(swimsuit or undergarments) and an acrylic cap. Thoracic gas volume was estimated for all
subjects using a predictive equation integral to the Bod Pod® software. Each subject wastested at least twice per visit. The Bod Pod was calibrated the morning of the testing session
and between each subject. The subjects were instructed to fast for at least 3 hrs and refrainfrom exercise the morning of testing.
Blood Analysis: Comprehensive Metabolic Panel
Subjects presented in a fasted state at a local Quest Diagnostics™ facility on five separate
occasions. A basic metabolic panel was done. Quest Diagnostics performed each test
according to the standard operating procedure of the company.
Statistical Analyses
The data are presented as means  SD. The statistical analysis was completed using Prism 6
GraphPad Software (La Jolla California).
RESULTSGroup Data
The subjects in the case studies consumed a high protein diet prior to the start of the firstyear of the study (2.5 g·kg-1·d-1). Each subsequent year, their protein intake increased to 3.2
and then 3.5 g·kg-1·d-1 (Table 1). Despite consuming a high-protein diet for a period of 2 yrs,
measures of liver and kidney function as well as blood glucose remained within the normal
clinical range (Table 2).
Table 1. Protein Intake Data of All Subjects.
Age
(yrs)

BaselinePRO
intake(g·d-1)

Year 1PRO
intake(g·d-1)

Year 2PRO
intake(g·d-1)BaselineYear 1
Year 2PRO
PRO
PRO
intakeintakeintake(g·kg-1·d-1) (g·kg-1·d-1) (g·kg-1·d-1)

Subject 1
Subject 2
Subject 3
Subject 4
Subject 5

25
26
30
31
38

138
193
395
184
163

217
278
524
250
198

255
285
562
222
200

1.5
2.7
4.0
2.2
2.0

2.2
3.4
5.1
3.0
2.5

2.6
3.6
5.8
2.7
2.6

MeanSD

30.0 5.1

215103293133305147

2.51.0

3.21.1

3.51.4

Data are expressed in yearly average protein intake. d = day; kg = kilogram; PRO = protein

17

Table 2. Select Clinical Measures of All Subjects.

Glucose (mg·dL-1)
BUN (mg·dL-1)
Creatinine (mg·dL-1)
eGFR mL·min-1·1.73 m-2
AST U/LALT U/L

BaselineYear 1

Year 2

Normal Range

83 ± 624 ± 61.2 ± 0.4
97 ± 27
31 ± 829 ± 1279 ± 221 ± 91.1 ± 0.5
102 ± 26
27 ± 528 ± 1186 ± 424 ± 81.2 ± 0.2
95 ± 28
28 ± 526 ± 765 to 99 (mg·dL-1)
7 to 25 (mg·dL-1)
0.60 to 1.35 (mg·dL-1)> or = 60 mL·min-1·1.73 m-2
10 to 40 U/L
9 to 46 U/L

Data are mean ± SD. ALT = alanine transaminase; AST = aspartate transaminase; BUN = blood urea nitrogen;
eGFR = estimated glomerular filtration rate; g = grams; L = liter; and mg = milligrams. All values fall within thenormal range.

Individual Data
In general, the basic metabolic panel data showed no alterations over the course of the 2-yr
period with a few exceptions. Subject #4 was the only individual whose values never deviatedoutside of the normal range. Subject #1 had high BUN levels at baseline and at 2 yrs, but not
at year 1. Subject #1 also had elevated creatinine at baseline and year 1, but not at year 2.
Subject #2 had high levels of BUN at baseline only. Subject #3 had high levels of BUN atyear 1 and 2 but not at baseline. In addition, he had higher levels of creatinine at year 2 andAST at baseline. Subject #5 had high levels of BUN at year 2 only. Table 3 contains all of theindividual data.
Table 3. Individual Data of Subjects 1-5.
Subject 1
Body Composition

BaselineYear 1

Year 2

Body Mass (kg)Lean Body Mass (kg)Fat Mass (kg)Body Fat %

93.5
85.2
8.3
8.9

98.1
83.6
14.4
14.6

96.8
87.9
8.8
9.2

Diet Composition

BaselineYear 1

Year 2

Protein (g·d-1)
Carbohydrate (g·d-1)
Fat (g·d-1)
Cholesterol (mg·d-1)
Sodium (mg·d-1)
Sugar (g·d-1)
Fiber (g·d-1)

138
322
103
466
4510
103
24

217
246
93
700
4545
85
21

255
244
95
569
4391
69
25

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Metabolic Panel
Glucose (mg·dL-1)
BUN (mg·dL-1)
Creatinine (mg·dL-1)
eGFR
AST U/LALT U/L

BaselineYear 1

Year 2

Normal Range

85
33*
1.44*
68
34
26

75
24
1.46*
66
20
16

84
26*
1.30
72
32
24

65 to 99 mg·dL-1
7 to 25 mg·dL-1
0.60 to 1.35 mg·dL-1> or = 60 mL·min-1·1.73 m-2
10 to 40 U/L
9 to 46 U/L

ALT = alanine transaminase; AST = aspartate transaminase; BUN = blood urea nitrogen; g = gram; d = day; dl= deciliter; eGFR = estimated glomerular filtration rate; kg = kilogram; UL = units per liter; *Outside of thenormal range

Subject 2
Body Composition

BaselineYear 1

Year 2

Body Mass (kg)Lean Body Mass (kg)Fat Mass (kg)Body Fat %

72.9
59.4
13.5
18.6

80.4
56.9
23.4
27.4

78.9
59.5
19.4
24.6

Diet Composition

BaselineYear 1

Year 2

Protein (g·d-1)
Carbohydrate (g·d-1)
Fat (g·d-1)
Cholesterol (mg·d-1)
Sodium (mg·d-1)
Sugar (g·d-1)
Fiber (g·d-1)

193
187
83
539
3932
89
15

278
350
72
403
2160
50
21

285
261
76
500
1799
33
27

Metabolic Panel
Glucose (mg·dL-1)
BUN (mg·dL-1)
Creatinine (mg·dL-1)
eGFR
AST U/LALT U/L

BaselineYear 1

Year 2

Normal Range

89
26*
0.97
126
35
42

78
12
0.90
117
30
32

85
16
1.02
117
28
25

65 to 99 (mg·dL-1)
7 to 25 (mg·dL-1)
0.60 to 1.35 (mg·dL-1)> or = 60 mL·min-1·1.73 m-2
10 to 40 U/L
9 to 46 U/L

ALT = alanine transaminase; AST = aspartate transaminase; BUN = blood urea nitrogen; g = gram; d = day; dl= deciliter; eGFR = estimated glomerular filtration rate; kg = kilogram; UL = units per liter; *Outside of thenormal range

19

Subject 3
Body Composition

BaselineYear 1

Year 2

Body Mass (kg)Lean Body Mass (kg)Fat Mass (kg)Body Fat %

99.1
81.7
17.9
17.6

95.1
80.3
21.9
15.3

97.7
85.4
12.3
12.6

Diet Composition

BaselineYear 1

Year 2

Protein (g·d-1)
Carbohydrate (g·d-1)
Fat (g·d-1)
Cholesterol (mg·d-1)
Sodium (mg·d-1)
Sugar (g·d-1)
Fiber (g·d-1)

395
107
48
50
1210
13
42

524
180
109
871
4236
32
46

562
122
108
1322
4905
25
23

Metabolic Panel
Glucose (mg·dL-1)
BUN (mg·dL-1)
Creatinine (mg·dL-1)
eGFR
AST U/LALT U/L

BaselineYear 1

Year 2

Normal Range

77
25
1.26
76
42*
42

79
33*
1.02
97
32
45

89
34*
1.50*
61
32
38

65 to 99 (mg·dL-1)
7 to 25 (mg·dL-1)
0.60 to 1.35 (mg·dL-1)> or = 60 mL·min-1·1.73 m-2
10 to 40 U/L
9 to 46 U/L

ALT = alanine transaminase; AST = aspartate transaminase; BUN = blood urea nitrogen; g = gram; d = day; dl= deciliter; eGFR = estimated glomerular filtration rate; kg = kilogram; UL = units per liter; *Outside of thenormal range

Subject 4
Body Composition

BaselineYear 1

Year 2

Body Mass (kg)Lean Body Mass (kg)Fat Mass (kg)Body Fat %

82.7
70.9
11.7
14.3

82.6
70.1
12.5
15.1

80.8
68.9
11.7
14.6

20

Diet Composition

BaselineYear 1

Year 2

Protein (g·d-1)
Carbohydrate (g·d-1)
Fat (g·d-1)
Cholesterol (mg·d-1)
Sodium (mg·d-1)
Sugar (g·d-1)
Fiber (g·d-1)

184
405
43
90
3066
29
71

250
388
85
12
4225
65
50

222
332
69
6
3522
83
60

Metabolic Panel
Glucose (mg·dL-1)
BUN (mg·dL-1)
Creatinine (mg·dL-1)
eGFR
AST U/LALT U/L

BaselineYear 1

Year 2

Normal Range

76
18
0.95
125
25
15

81
12
0.85
135
27
24

82
19
1.30
125
28
22

65 to 99 (mg·dL-1)
7 to 25 (mg·dL-1)
0.60 to 1.35 (mg·dL-1)> or = 60 mL·min-1·1.73 m-2
10 to 40 U/L
9 to 46 U/L

ALT = alanine transaminase; AST = aspartate transaminase; BUN = blood urea nitrogen; g = gram; d = day; dl= deciliter; eGFR = estimated glomerular filtration rate; kg = kilogram; UL = units per liter; *Outside of thenormal range

Subject 5
Body Composition

BaselineYear 1

Year 2

Body Mass (kg)Lean Body Mass (kg)Fat Mass (kg)Body Fat %

82.5
68.2
14.2
17.3

78.1
65.3
12.7
16.4

77.8
66.7
11.0
14.2

Diet Composition

BaselineYear 1

Year 2

Protein (g·d-1)
Carbohydrate (g·d-1)
Fat (g·d-1)
Cholesterol (mg·d-1)
Sodium (mg·d-1)
Sugar (g·d-1)
Fiber (g·d-1)

163
205
73
691
4606
49
20

198
197
67
348
3427
58
27

200
252
78
369
3609
86
27

21

Metabolic Panel
Glucose (mg·dL-1)
BUN (mg·dL-1)
Creatinine (mg·dL-1)
eGFR
AST U/LALT U/L

BaselineYear 1

Year 2

Normal Range

88
18
1.25
89
21
20

80
23
1.18
95
24
22

92
31*
1.13
99
21
23

65 to 99 (mg·dL-1)
7 to 25 (mg·dL-1)
0.60 to 1.35 (mg·dL-1)> or = 60 mL·min-1·1.73 m-2
10 to 40 U/L
9 to 46 U/L

ALT = alanine transaminase; AST = aspartate transaminase; BUN = blood urea nitrogen; g = gram; d = day; dl= deciliter; eGFR = estimated glomerular filtration rate; kg = kilogram; UL = units per liter; *Outside of thenormal range

DISCUSSION
Kidney and Liver Function
This is the fifth study in a series of investigations that have examined the effects of a highprotein diet (≥2.2 g·kg-1·d-1) (1-4). The five resistance trained males in the current study had
consumed a high protein diet for 2 yrs. The mean values for all of the parameters (groupdata) showed no harmful effects of protein consumption. When the individual data were
examined, a few of the clinical values were slightly outside of the normal range. However,there was no consistent pattern. Subject #4 was the only individual whose values neverdeviated outside of the normal range. In general, four subjects had elevated BUN levels,
whereas two had elevated creatinine levels. However, there was no temporal pattern to thisfinding.
Interestingly, acute exercise by itself can result in an increase in BUN and creatinine (9). For
instance, “concentrations of glucose, total protein, albumin, uric acid, calcium, phosphorus,
serum urea nitrogen, creatinine, bilirubin, alkaline phosphatase, alanine aminotransferase,
aspartate aminotransferase, total creatine kinase, creatine kinase-MB, myoglobin, and theanion gap were increased after a marathon race, which is consistent with the effects ofexertional rhabdomyolysis and hemolysis” (13). Also, post-marathon creatinine as well asother markers of muscle damage were elevated (12).
Our subjects were well-trained bodybuilders. Thus, it is not clear if the volume of training they
performed was sufficient to produce a rise in creatinine or BUN. On the other hand, we did
not control for their training or exercise. Thus, it is entirely possible that the acute exercise
may have altered their blood chemistry values. Nevertheless, when one examines the groupmean, there were no untoward alterations in their blood chemistry.
Higher protein consumption has been shown to elevate GFR levels, as reported in a study by
Bilo et al. (6) in 6 subjects with normal renal function, as well as 9 subjects with chronic renal
insufficiency. During this investigation, different kinds of protein sources were tested (beef,
lactoprotein, and soy). Beef consumption, chronic and acute, showed the highest response inelevating GFR levels, compared to the other protein sources in both the groups tested. On
the other hand, the Nurse’s Health Study (11) assessed higher protein intake in 1624 women(42 to 68 yrs) from 1989 to 2000. They found that “high protein intake was not associatedwith renal function decline in women with normal renal function. However, high total protein

22

intake, particularly high intake of nondairy animal protein, may accelerate renal function
decline in women with mild renal insufficiency.” Work by Berryman et al. (5) looked at higher
protein intake from animal, dairy, and plant sources (mean ± SE total protein intake 82.3 ± 0.8
g·d-1) in 11,111 adults with the use of 24-hr recall. They concluded that higher plant andanimal protein intake was associated with no negative effects on kidney function, improved
central adiposity, and cardio-metabolic benefits. A 7-day study by Poortmans et al. (16)concluded that protein intake under 2.8 g·kg-1·d-1 does not impair renal function in well-trained
athletes.
It is clear from our investigations and others that the consumption of a high-protein diet,particularly in healthy exercise trained individuals has no harmful effect on renal function (13,7,15,16). The concern over higher protein intake on the liver was raised in a review by
Bilsborough and Mann (7). They stated that high protein diets of 200 to 400 g·d-1, which canequate to levels of approximately 5 g·kg-1·d-1, may exceed the liver's capacity to convert
excess nitrogen to urea. Yet, interestingly, this speculation is not supported by researchfindings. In fact, our data in human subjects consuming >200 grams of protein daily showedno effect on markers of liver function (i.e., AST and ALT). The resistance trained subjects in
our investigation consumed more than 2.2 grams of protein per kilogram of body weight per
day for the 2 yrs.
Body Composition
The five resistance trained males (>9 yrs of training) demonstrated for the most part rather
inconsistent changes in body composition. There were no clear trends in lean body mass or
fat mass. Our prior investigations (1,2) have shown that a higher intake of protein with orwithout a change in training might promote a loss of fat mass. Nonetheless, it is unclear why
higher protein intakes may promote a loss of fat mass in the short-term, but have no lasting
effect over the course of years. Perhaps, in the short term, changes in exercise energy
expenditure and, perhaps, non-exercise activity thermogenesis (NEAT) might account in partfor the greater changes in body composition in those that consume large quantities of protein(14,18).
According to Levine et al. (14), NEAT can vary between individuals by as much as 2000 kcals
daily. Therefore, one might speculate that the more advanced training status of the highprotein group might lend itself to greater NEAT. Protein has a thermic effect of feeding (TEF)of 19 to 23% in both obese and lean individuals. On the other hand, carbohydrate isapproximately 12 to 14% (17). We would speculate that the primary effect of protein
overfeeding is in the effect on NEAT. Future work should examine the effect of protein
overfeeding on NEAT to determine if this is the cause, at least in the short-term, of thedecrement in fat mass.
Limitations of this Study
One of the limitations of this investigation is the case study design. Nonetheless, it is clearthat at least in this small cohort of resistance trained men, there were no harmful effects of ahigh protein diet. Another limitation of this study is the use of dietary self-reports. Subjects
were provided protein powder to help maintain the additional protein, which could provide fora more accurate recall if they ingested it as the additional protein source added to theirnormal daily diet.

23

CONCLUSIONSThis is the first 2-yr investigation in resistance-trained males on the effects of consuming ahigh protein diet. We found no deleterious effects on liver or kidney function. Furthermore,
there were no significant alterations in body composition. Future studies should focus oncontinuing to monitor exercise trained individuals on the effects of a high protein diet for
longer periods of time. Also, studies in women are non-existent in relation to higher protein
intakes.
ACKNOWLEDGMENT
We would like to thank Dymatize and Growing Naturals for providing us the milk-based andvegan protein powder, respectively.
Address for correspondence: Jose Antonio, PhD, FNSCA, FISSN, CSCS, Department of
Health and Human Performance, Nova Southeastern University, Davie FL USA. Email: ja839@nova.edu
REFERENCES
1. Antonio J, Ellerbroek A, Silver T, Orris S, Scheiner M, Gonzalez A, Peacock CA. A
high protein diet (3.4 g/kg/d) combined with a heavy resistance training program
improves body composition in healthy trained men and women: A follow-up
investigation. J Int Soc Sports Nutr. 2015;12:39.
2. Antonio J, Ellerbroek A, Silver T, Vargas L, Peacock C. The effects of a high protein
diet on indices of health and body composition: A crossover trial in resistance-trained
men. J Int Soc Sports Nutr. 2016;13:3.
3. Antonio J, Ellerbroek A, Silver T, Vargas L, Tamayo A, Buehn R, Peacock CA. A highprotein diet has no harmful effects: A one-year crossover study in resistance-trained
males. J Nutr Metab. 2016;9104792.
4. Antonio J, Peacock CA, Ellerbroek A, Fromhoff B, Silver T. The effects of consuming ahigh protein diet (4.4 g/kg/d) on body composition in resistance-trained individuals. J
Int Soc Sports Nutr. 2014;11:19.
5. Berryman CE, Agarwal S, Lieberman HR, Fulgoni VL, 3rd, Pasiakos SM. Diets higher
in animal and plant protein are associated with lower adiposity and do not impair
kidney function in US adults. Am J Clin Nutr. 2016;104:743-749.
6. Bilo HJ, Schaap GH, Blaak E, Gans RO, et al. Effects of chronic and acute protein
administration on renal function in patients with chronic renal insufficiency. Nephron.
1989;53:181-187.
7. Bilsborough S, Mann N. A review of issues of dietary protein intake in humans. Int J
Sport Nutr Exerc Metab. 2006;16:129-152.

24

8. Campbell B, Kreider RB, Ziegenfuss T, La Bounty P, Roberts M, Burke D, Landis J,
Lopez H, Antonio J. International Society of Sports Nutrition Position Stand: Protein
and Exercise. J Int Soc Sports Nutr. 2007;4:8.
9. Foran SE et al. Effects of exercise on laboratory test results. Lab Med. 2003;34:736742.
10. Jager R, Kerksick CM, Campbell BI, Cribb PJ, Wells SD, Skwiat TM, Purpura M,
Ziegenfuss TN, Ferrando AA, Arent SM, et al. International Society of Sports Nutrition
Position Stand: Protein and Exercise. J Int Soc Sports Nutr. 2017; 14:20.
11. Knight EL, Stampfer MJ, Hankinson SE, Spiegelman D, Curhan GC. The impact ofprotein intake on renal function decline in women with normal renal function or mild
renal insufficiency. Ann Intern Med. 2003;138:460-467.
12. Kraemer RR, Brown BS. Alterations in plasma-volume-corrected blood components ofmarathon runners and concomitant relationship to performance. Eur J Appl Physiol
Occup Physiol. 1986;55:579-584.
13. Kratz A, Lewandrowski KB, Siegel AJ, Chun KY, Flood JG, Van Cott EM, LeeLewandrowski E. Effect of marathon running on hematologic and biochemicallaboratory parameters, including cardiac markers. Am J Clin Pathol. 2002;118:856863.
14. Levine JA, Vander Weg MW, Hill JO, et al. Non-exercise activity thermogenesis: The
crouching tiger hidden dragon of societal weight gain. Arterioscler Thromb Vasc
Biol. 2006;26:729-736.
15. Martin WF, Armstrong LE, Rodriguez NR. Dietary protein intake and renal function.
Nutr Metab (Lond). 2005;2:25.
16. Poortmans JR, Dellalieux O. Do regular high protein diets have potential health risks
on kidney function in athletes? Int J Sport Nutr Exerc Metab. 2000;10:28-38.
17. Swaminathan R, King RF, Holmfield J, Siwek RA, Baker M, Wales JK. Thermic effectof feeding carbohydrate, fat, protein and mixed meal in lean and obese subjects. Am J
Clin Nutr. 1985;42:177-181.
18. Teske JA, Billington CJ, Kotz CM. Neuropeptidergic mediators of spontaneous
physical activity and non-exercise activity thermogenesis. Neuroendocrinol. 2008;87:
71-90.
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