hyperprotein diets
TRANSCRIPT
Hyperprotein Diets
Dr. Clarence P. DavisBergstrasse 8
CH-8702 Zollikon
Dr. C.P. Davis
Subjects
General remarks on Obesity an associated riscs
Role of Protein in the Diet Definition of high Protein Diets High Protein Diets and Weight
Reduction– Atkins, Zone, Protein Power, Sugar
Busters, Stillman
Dr. C.P. Davis
19961991
Obesity Trends* Among U.S. AdultsBRFSS, 1991, 1996, 2004
(BMI 30)
No Data <10% 10%–14% 15%–19% 20%–24% ≥25%
2004
Source: Centers for Disease Control and Prevention
Dr. C.P. Davis
Obesity in EuropeSource: IOTF
YugoslaviaGreece
RomaniaCzech Rep.
EnglandFinland
GermanyScotlandSlovakiaPortugal
SpainDenmarkBelgiumSwedenFrance
ItalyNetherlands
NorwayHungary
Switzerland
30 4030040 20 10 10 20
women men
% BMI 30
Dr. C.P. Davis
Consequences of Obesity cardiovascular diseases
gallbladder disease
hormonal imbalances
hyperuricemia and gout
diabetes
cancer- breast- uterus- gallbladder- kidney- colon
gastro esophageal reflux
osteoarthritis
Dr. C.P. Davis
Risks associated with ObesityClassification
BMI kg/m2
Risk for concomitant disease*
waist circumference<102 cm (men) >102 cm (men) <88 cm (women)>88 cm (women)
Underweight <18.5Normal weight 18.5 – 24.9Overweight 25.0 – 29.9 increased high
Obesity Grade I 30.0 – 34.9 high strongly increased
Obesity Grade II 35.0 – 39.9 strongly increased
strongly increased
Obesity Grade III >40.0 very high very high*related to normal weight and normal waist circumference, risk for type 2 diabetes, hypertension, CHD.NIH/NHLBI The Practical Guide, Identification, Evaluation and Treatment of Overweight and Obesity in Adults, October 2000.
Dr. C.P. Davis
Obesity and heart failure: cumulative incidence in women
Kenchaiah S et al N Engl J Med. 2002 Aug 1;347(5):305-13
BMI 18.5-24.9kg/m2
BMI 25.0-29.9kg/m2
BMI >30 kg/m2
Dr. C.P. Davis
Obesity and heart failure: cumulative incidence in men
Kenchaiah S et al N Engl J Med. 2002 Aug 1;347(5):305-13
BMI 18.5-24.9kg/m2
BMI 25.0-29.9kg/m2
BMI >30 kg/m2
Dr. C.P. Davis
BMI and age related mortality
after Waaler HT Acta Med Scand Suppl. 1984;679:1-56
Rel
ativ
e ris
k
women
BMI (kg/m2)21
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
25 29 33 37 41
men age50-5455-5960-64
BMI (kg/m2)21
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
25 29 33 37 41
Dr. C.P. Davis
The diet generation ~ 30% of all male and ~ 45% of all
female US citizens are trying to lose weight
Diet books available on Amazon.com: ~ 38’000
Many of these books promote some sort of CHO restriction and hyperprotein diet– Dr. Atkins’ New Diet Revolution, The
Carbohydrate Addict’s Diet, Protein Power, Lauri’s Low-Carb Cookbook
Dr. C.P. Davis
Important Questions What is really known about CHO
restriction? Is the information scientifically sound?
What is the effect on composition of– weight loss (fat vs. LBM)– micronutrient status (vitamins and
minerals)– metabolic parameters (blood glucose,
insulin sensitivity, blood pressure, lipid levels, uric acid, ketone bodies)?
Dr. C.P. Davis
Role of Protein in the Diet Proteins are essential components of the
body and are required for the body’s structure and proper function– Enzymes, hormones, antibodies, transport and
structural components The nutritional quality of food proteins
varies and depends on essential amino acid composition (egg white = biological value of 100)
Foods with high protein quality are from animal source– eggs, milk, meat, poultry, fish
Dr. C.P. Davis
Role of Protein in the Diet In the US an average of 102 g of protein per
person per day is available in the food supply– Actual protein consumption ranges from 88 to 92
g for men and 63 to 66 g for women (12-15 % of total daily energy uptake)
Animal products provide ~ 75% of the essential amino acids in the food supply, followed by dairy products, cereal products, eggs, legumes, fruits, and vegetables
The RDA for protein of high biological value for adults is ~ 0.8 g/kg BW (~ 8-10% of total daily energy uptake)
Dr. C.P. Davis
Definition of high protein diets
High protein diets: >20% of total energy
Very high protein diets: >30% of total energy
Dr. C.P. Davis
Protein Intake at Various Levels of Energy Intake
Energy Intake, kcal/d
LPD(<10% cal)
AD(~15% kcal)
HPD(>20% kcal)
VHPD(>30% kcal)
1200 30 45 60 90
2000 50 75 100 150
3000 75 112 150 225
Protein intake is in grams per day.
St. Jeor ST, Ashley JM. In: Obesity: Impact on Cardiovascular Disease. 1999:233-246.
Dr. C.P. Davis
Compensatory Changes in the Macronutrient Composition of Various
Diets
Diet DescriptionFat(% kcal)
CHO(% kcal)
Protein(% kcal)
Alcohol(% kcal)
Average diet 34 49 14 3Moderate-fat diet 30 55 15 ...Very-low-fat/very-high-CHO diet
15 70 15 ...
Low-CHO/very-high-protein diet
30 40 30 ...
Very-low-CHO/very-high-protein/fat diet
55 15 30 ...
Dr. C.P. Davis
Some popular Diets Atkins
– Eating too many CHO causes obesity and other health problems; ketosis leads to decreased hunger
– Meat, fish, poultry, eggs, cheese, low-CHO vegetables, butter, oil; no alcohol
– Protein: 27%, CHO: 5%, Fat: 68% (saturated 26%)
– No long term validated studies published– Initial weight loss mostly water. Difficult to
maintain long-term because diet restricts food choices
Dr. C.P. Davis
Some popular Diets Zone (Montignac)
– Eating the right combination of foods leads to metabolic state at which body functions at peak performance, leading to decreased hunger, weight loss, and increased energy
– Protein, fat, CHO must be eaten in exact proportions (40/30/30). Low-glycemic-index foods, alcohol in moderation
– Protein: 34%, CHO: 36%, Fat: 29% (saturated 9%), Alcohol: 1%
– No long term validated studies published. Theories highly questionable.
– Weight loss based on caloric restriction. Could result in weight maintenance if carefully followed. Diet rigid and difficult to maintain.
Dr. C.P. Davis
Some popular Diets Protein Power
– Eating CHO releases insulin in large quantities, which contributes to obesity and other health problems
– Meat, fish, poultry, eggs, cheese, low-CHO vegetables, butter, oil, salad dressings, alcohol in moderation
– Protein: 26%, CHO: 16%, Fat: 54% (saturated 18%), Alcohol: 4%
– No long term validated studies published – Weight loss based on caloric restriction.
Limited food choices not practical for long term.
Dr. C.P. Davis
Some popular Diets Stillman
– High-protein foods burn body fat. If CHO are consumed, the body stores fat instead of burning it
– Lean meats, skinless poultry, lean fish and seafood, eggs, cottage cheese, skim-milk products; no alcohol
– Protein: 64%, CHO: 3%, Fat: 33% (saturated 13%)
– No long term validated studies published – Initial weight loss mostly water.
Maintenance based on strict caloric counting. Very limited food choices not practical for long term.
Dr. C.P. Davis
Comparison of various diets with regard to Body Fat, Body Protein and Body
Water
37
20
43
16
21
63
11
23
66
3
18
79
4
21
75
11
22
67
25
19
56
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
TF MF 1 MF 2 MF 3 MF 4 BN 1 SK 1
TF = total fasting; MF = Modifast, BN = formula with inferior protiens; SK = Schrotkur
Loss of body fat, body protein and body water with differend diets
The best results were
achieved with a
combination of 50 g of
proteins, 25 g CHO, and 10 g of fat
Wechsler JG et al. Fortschr Med. 1984 Jun 28;102(24):666-8
Dr. C.P. Davis
Effects of HPD Skov et al. Int J Obes Relat Metab
Disord. 1999; 23:528-536– 65 healthy overweight men and women– 2 ad lib fat reduced (< 30% kcal) diets
varying in protein content (12% vs 25% of kcal) over 6 months
– Larger weight loss with higher-protein diet (8.9 kg) vs lower-protein diet (5.1 kg)
– Larger fat loss with higher-protein diet (7.6 kg) vs lower-protein diet (4.3 kg)
Dr. C.P. Davis
Effects of HPD
On average, consumption of HPD and/or low-CHO diets resulted in 12-wk and 24-wk weight losses that were 2.5 ± 1.8 and 4.0 ± 0.4 kg greater, respectively, than those from consumption of the high CHO and/or low-fat control diets.– This implies a 233 kcal/day difference in
energy balance
Dr. C.P. Davis
Effects of HPD
Two possible hypotheses for difference in energy balance– 1) a low-CHO diet may increase energy
expenditure– 2) an increase in protein in the diet may
increase energy expenditure
Dr. C.P. Davis
Do Proteins increase Energy Expenditure?
Mikkelsen et al. Am J Clin Nutr. 2000; 72:1135:1141– Ad lib diet– Increase of protein from 11% to 28/29%– No change in fat (29%)– Reduction of CHO from 60% to 42/43%– Increase in energy expenditure by about
60 – 120 kcal/24 hour, depending on whether the protein was of plant or animal origin
Dr. C.P. Davis
Do Proteins increase Energy Expenditure?
Whitehead JM et al. Int J Obes Relat Metab Disord. 1996; 20:727-732– 50% energy restricted diet– Increase of protein from 15 – 36%– Compared with the weight-maintenance control
diet both diets resulted in a reduction of 24-hour energy expenditure
– Smaller reduction for higher-PD by 71 kcal/d compared with the lower-PD Lesser decrease of resting metabolic rate Lesser decrease of thermic effect of food
Dr. C.P. Davis
Do Proteins increase Energy Expenditure?
Not sure Small results cannot explain the effect
of the average 2.5 kg greater weight loss reported from low-CHO diets
Dr. C.P. Davis
Reasons for higher Weight loss with HPD
Dietary compliance– Difficult to document– Some evidence from comparative studies
with low-fat diets vs. low-CHO/HPD and theoretical weight loss
– Possible higher satiating effect of proteins
Dr. C.P. Davis
Dansinger ML et al. JAMA. 2005 Jan 5;293(1):43-53
Comparison of different diets with respect to compliance
Mean Self-reported Dietary Adherence Scores of All 4 Diet Groups, According to Study Month
Calorie-restriction
CHO-restriction
Glucose-restriction
Fat-restriction
Dr. C.P. Davis
One-Year Changes in Body Weight as a Function of Diet Group and Dietary Adherence Level for All Study Participants
Dansinger ML et al. JAMA. 2005 Jan 5;293(1):43-53
Comparison of different diets with respect to weight loss
Dr. C.P. Davis
Reasons for higher Weight loss with HPD
Limitation of food choices associated with low-CHO diets
Low-CHO diets induce small losses of body water (~ 1.5-2 kg)– Does not explain the difference generally
reported for comparisons of low-CHO and low-fat diets 1.9 kg is lesser than reported Greater weight loss is reported to be based on
fat loss not water
Dr. C.P. Davis
Limitations of current studies and outlook
Very few “pure” studies on HPD– Impossibility of manipulating one
macronutrient without changes in at least one other macronutrient
Studies on energy expenditure may not give the right picture– Too short time frame
Weight losses found in 12 weeks may not be representative of long-term effect
Dr. C.P. DavisFoster GD et al. N Enlg J Med 2003 22;348(21):2082-90
Comparison of Weight Loss
Dr. C.P. DavisFoster GD et al. N Enlg J Med 2003 22;348(21):2082-90
Urinary Ketosis
Dr. C.P. Davis
Limitations of current studies and outlook
Usually studies investigate only one side of the energy balance equation
Health issues are rarely investigated– The amount of protein recommended in
HPD exceeds established requirement and may impose significant health risks
– Little cross-sectional and longitudinal studies provide data on health effects of HPD
Dr. C.P. Davis
Risks associated with HPD Animal protein, saturated fat, and cholesterol raises
LDL-cholesterol HPD increase purine levels
– gout HPD increase urinary calcium loss
– osteoporosis Deficiencies in essential vitamins, minerals, and
fibers Increased cancer risk
– low phytochemical) VHPD with excessive limitations of CHO may lead to
loss of lean muscle tissue (glyconeogenesis)Larosa JC et al. J Am Diet Assoc 1980; 77:264-270Franzese TA. In: Kause‘s Food, Nutrition, & Diet Therapy. 2000:970-986Barzel US et al. J Nutr 1998; 128:1051-1053Costill DL et al. Sports Med 1992; 13:86-92
Dr. C.P. Davis
High-protein Diets and Weight Reduction
Weight reduction is achieved if there is an energy deficit (energy uptake < energy expenditure)
In obese individuals, macronutrient composition has little effect on the rate or magnitude of weight loss unless nutrient composition influences caloric intake
Overall caloric intake depends on palatability and satiety
Proteins are easily available, palatable and of high essentiality
Dr. C.P. Davis
High-protein Diets and Weight Reduction
High-protein diets are initially attractive– quick weight loss due to low CHO intake,
glycogen depletion, and ketosis High-protein diets usually induce
metabolic ketosis Ketosis may lead to lower caloric
intake VHPD may promote negative energy
balance due to significant food restrictions
Dr. C.P. Davis
High-protein Diets and Weight Reduction
The structured eating plan, strict eating schedules, and limited tolerance for high-protein foods reduce overall flexibility but offer initial appeal. These characteristics may help limit caloric intake and may account for weight loss. However, neither the efficacy of these diets compared with higher COH diets in promoting weight loss nor the safety of these diets has been documented in long-term studies.
St. Jeor ST et al. Circulation 2001; 104; 1869-1874
Dr. C.P. Davis
General Recommendation for HPD
The current evidence, combined with the need to meet all nutrient requirements, suggests that weight-loss diets should be moderate in CHO, moderate in fat, and that protein should possibly contribute one fourth to one third of energy intake.