www.csiro.au

High Protein Low Carbohydrate Diets: Targeting Who Benefits

Dr Manny Noakes

Senior Research Dietitian

CSIRO Human Nutrition (Clinical Research Unit)

Diabetes risk increases with obesity and will more than double, from 140 million to 300 million in the next 25 years.

Diabetes leads to serious complications such as heart, eye and kidney disease and a shortened life span.

Costs of obesity to community > $6b/y

Obesity Epidemic

Other terms that are used that generally refer to the same syndrome include:

Syndrome X

Metabolic Syndrome

Insulin Resistance Syndrome

Deadly Quartet

Syndromic Obesity

Constellation of major risk factors, life-habit risk factors and emerging risk factors

Over-represented among populations with heart disease

Clue is distinctive body-type with increased abdominal circumference (although some leaner men and women can have metabolic syndrome)

Metabolic Syndrome

ATP III Guidelines

Glucose Abdominal Obesity HDL-C BP TG

Glucose 6.1mmol/LWaist Circumference

102cm 88cm

HDL-C≤ 1.0 mmol/L≤ 1.3 mmol/L

BP 130/85 mmHgTriglycerides 1.7mmol/L

Diagnosis is made when 3 or more of these risk criteria are met

Diagnostic Criteria for Metabolic Syndrome

InactivityAging

Atherosclerosis

Genetics

Obesity

PCOS

Dyslipidemia

Hypertension

Type 2 diabetes

NASH

Genetics

Insulin Resistance: Causes and Associated Conditions

INSULIN RESISTANCE

* Total area under 3-hour response curve (mean of 2 tests). Olefsky JM et al. Am J Med. 1974;57:551-560.

625

500

400

300

200

100

100 200 300 400 500 600

Insulin Response to Oral Glucose*

Pla

sma

TG

(m

g/d

L)

r = 0.73P < 0.0001

Insulin Resistance and Hypertriglyceridemia

Ford ES, et al JAMA 2002

45

35

0

8814 aged 20 years or older from NHANES III (1988-1994)

The age-adjusted prevalence : men (24.0%) women (23.4%)

Prevalence of Metabolic Syndrome

0

5

10

15

20

25

30

35

40

45

20-29 30-39 40-49 50-59 60-69 >70

Marketing Weight Loss

Skov et al 1999

High-carbohydrate

(HC, protein 12% energy) n=25

High-protein

(HP, protein 25% energy) n=25

Results After 6 Months

5.1 kg in the HC group

8.9 kg in the HP group (P < 0.001)

More subjects lost > 10 kg in the HP group (35% vs 9%).

HP diet decreased fasting plasma triglycerides significantly.

Protein Versus Carbohydrate in ad libitum Fat Reduced Diet

Greater weight and fat loss (Skov et al,1999)

Obese subjects

Increased satiety (Latner & Schwartz, 1999)

Glucose tolerant women

Thermic effects (Hwalla Baba et al,1999)

Obese, hyperinsulinaemic men

Lean body mass spared (Piatti et al,1994)

Glucose tolerant women

High protein/Low GI (Dumesnil et al)

25% decrease in ad libitum intake

Obese men

Increased Protein / Carbohydrate Ratio

Insulin sensitivity (Clifton et al,1998)

Subjects with IGT

Greater abdominal fat mass loss (Parker et al 2002)

Type 2 diabetes

Greater lowering of LDL-C (Parker et al 2002)

Type 2 diabetes

Thermic effect of HP meal 28% greater (Luscombe et al 2002)

No change in REE

Type 2 diabetes

Greater lowering of TG (Farnsworth et al (in press))

Subjects with elevated insulin

Lean body mass spared (Farnsworth et al (in press))

Subjects with elevated insulin

Increase Protein / Carbohydrate Ration: CSIRO Studies

Renal Function

Urinary albumin excretion was not affected by dietary protein during weight loss:

N=19 with microalbuminuria.

HP diet: 24.2 to 19.8 mg/l (n=12)

LP diet: 4.3 to 3.5 mg/l (n=7)

Aim

To compare a high protein weight loss diet with a high carbohydrate diet in women participating in a 12 week intervention (and subsequent follow up for 1 year) on the following outcomes:

Weight loss and body composition

Nutrient status

Bone turnover markers

Measures of heart disease risk

.

Diets:

High carbohydrate

High protein, high red meat

High Meat Protein (5600 KJ)

Cereal

Low fat milk (250ml)

Wholemeal bread (2 slices)

Fruit (2)

Beef / lamb 200g - dinner

Chicken/fish/meat 100g - lunch

Vegetables 2.5 cups

Diet Yoghurt 200g

Canola oil 3 tsp

Wine 2 glasses/week (optional)

34% protein 20% fat 46% carbohydrate

109g protein 31g fat 161g carbohydrate

Cereal

SKIM milk (250ml)

Wholemeal bread (3 slices)

Fruit (3)

Chicken / pork / fish 80g

Vegetables 2.5 cups

Canola oil 3 tsp

Pasta/rice 120g cooked

Low fat biscuits 3

Wine 2 glasses/week (optional)

High Carbohydrate (5600 KJ)

17% protein 20% fat 64% carbohydrate

57g protein 31g fat 229g carbohydrate

Overall Results

Diet Average Weight Loss

Min Weight Loss

Max Weight Loss

N Dropouts

High Protein 7.6kg 0.55kg 18.2kg 51 5

High Carbohydrate 6.9kg 0.15kg 14.5kg 49 16

Weight Loss by Triglyceride Status

8.2

9.29.3

6.9

3

4

5

6

7

8

9

10

Low TG High TG

wei

gh

t lo

ss (

kg)

* Sig Diet Effect

High Protein

High Carb

Arm Fat

Leg Fat

Abdominal Fat

DEXA

5.135.86

6.28

3.63

0

2

4

6

8

high protein -low TG

highcarbohydrate-

low TG

high protein -high TG

highcarbohydrate-

high TG

kgTotal And Midriff Fat Loss - DEXA Data

* Sig Diet Effect

High Protein

High Carb

LDL Cholesterol

2

2.5

3

3.5

4

4.5

5

week 0 week 4 week 8 week 12

LD

L-C

mm

ol/L

4.8% High Protein

High Carb

Triglycerides

0.5

1

1.5

2

2.5

3

week 0 week 4 week 8 week 12

TG

(m

mo

l/L)

4%

13%

High Protein

High Carb

Triglycerides by TG status

0

0.5

1

1.5

2

2.5

week 0 week 4 week 8 week 12

TG

mm

ol/L

HIGH TG

LOW TG

10%

28%

High Protein

High Carb

DIET

% c

han

ge

in T

G30

20

10

0

-10

insulin split

low insulin

high insulin

High Protein High Carb

P=0.036

26%

9%

Triglyceride Change By Insulin Status

Ch

ang

e in

TG

Insulin Split

Low Insulin

High Insulin

Cal

ciu

m e

xcre

tio

n m

mo

l/24

hr

High Protein High Carb

Week 0

Week 12

Reference Range: 2.5-7.5mmol/24hr

Calcium Excretion

Calcium excretion decreased on both diets

Protein versus Carbohydrate and Markers of Bone Turnover

Deoxypyridinoline/creatinine ratio Pyridinolone /creatinine ratio

High Protein High CarbHigh Protein High Carb

Both weight loss strategies associated with increased bone turnover.No effect of diet composition.

Week 0

Week 12

Haemoglobin

High Protein High Carb

Reference Range:115-165g/L

*

No change

Mea

n

Week 0

Week 12

Vitamin B12

High Protein High Carb

Reference Range: 140-700pmol/L12%

increase

13%decrease

Week 0

Week 12

Conclusion #1

Moderately High protein high red meat diets and conventional high carbohydrate weight loss diets provide health benefits.

Plasma triglycerides lowered on average 9%.

LDL cholesterol lowered on average 5%.

Insulin lowered on average 19%.

Glucose lowered on average 4%.

Conclusion #2

Moderately high protein high red meat diets provide advantages in women.

Greater weight, fat and midriff loss on high protein diet in those women with elevated TG.

Greater lowering of plasma triglycerides on high protein diet in those women with elevated insulin or TG.

Haemoglobin levels improved more on high protein high red meat diet.

B12 status improved on high protein high red meat diet.

Conclusion #3

Moderately high protein diets can be a safe and effective option to conventional high carbohydrate weight loss diets.

For some, HP diet may be easier to follow for longer periods as it may be more satisfying.

HP diet as used in this study is safe and nutritionally adequate.

It was easier to achieve RDI for all nutrients on HP diet.

Questions?

Book 1 published in May 2005.

Booklet released in August 2003 in the Australian Women’s weekly, then as a free booklet by Meat & Livestock Australia (MLA).

www.csiro.au

Thank You

CSIRO Human Nutrition

Name Associate Professor Dr Manny Noakes

Title Senior Dietitian / Research Scientist

Phone +61 8 8303 8827

Email manny.noakes@csiro.au

Web www.csiro.au/twd

Contact CSIRO

Phone 1300 363 400

+61 3 9545 2176

Email enquiries@csiro.au

Web www.csiro.au