High Protein Low Carbohydrate Diets: Targeting Who Benefits

1. High Protein Low Carbohydrate Diets: Targeting Who Benefits Dr Manny Noakes Senior Research Dietitian CSIRO Human Nutrition (Clinical Research Unit)

2. Obesity Epidemic • 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

3. Syndromic Obesity Other terms that are used that generally refer to the same syndrome include: • Syndrome X • Metabolic Syndrome • Insulin Resistance Syndrome • Deadly Quartet

4. Metabolic Syndrome • 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)

5. Diagnostic Criteria for Metabolic Syndrome Diagnosis is made when 3 or more of these risk criteria are met • Glucose  6.1mmol/L • Waist Circumference •  102cm  88cm HDL-C • ≤ 1.0 mmol/L ≤ 1.3 mmol/L BP 130/85 mmHg Triglycerides  1.7mmol/L  Glucose Abdominal Obesity  HDL-C  BP  TG ATP III Guidelines

6. Insulin Resistance: Causes and Associated Conditions Aging Inactivity Obesity Genetics Genetics INSULIN RESISTANCE Type 2 diabetes PCOS NASH Hypertension Atherosclerosis Dyslipidemia

7. Insulin Resistance and Hypertriglyceridemia 625 500 400 300 200 100 r = 0.73 P < 0.0001 Plasma TG (mg/dL) 100 200 300 400 500 600 Insulin Response to Oral Glucose* * Total area under 3-hour response curve (mean of 2 tests). Olefsky JM et al. AmJMed. 1974;57:551-560.

8. Prevalence of Metabolic Syndrome 8814 aged 20 years or older from NHANES III (1988-1994) 45 35 0 The age-adjusted prevalence : men (24.0%) women (23.4%) Ford ES, et al JAMA 2002

9. Marketing Weight Loss

10. Protein Versus Carbohydrate in ad libitum Fat Reduced Diet 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.

11. Increased Protein / Carbohydrate Ratio 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

12. Increase Protein / Carbohydrate Ration: CSIRO Studies • 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

13. 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)

14. 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

15. 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

16. High Carbohydrate (5600 KJ) • 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) 17% protein 20% fat 64% carbohydrate 57g protein 31g fat 229g carbohydrate

17. Overall Results

18. Weight Loss by Triglyceride Status * Sig Diet Effect High Protein High Carb

19. DEXA Arm Fat Abdominal Fat Leg Fat

20. Total And Midriff Fat Loss - DEXA Data * Sig Diet Effect High Protein High Carb

21. LDL Cholesterol 4.8% High Protein High Carb

22. Triglycerides High Protein 4% High Carb 13%

23. Triglycerides by TG status HIGH TG 10% 28% LOW TG High Protein High Carb

24. Triglyceride Change By Insulin Status P=0.036 26% Insulin Split Change in TG Low Insulin High Insulin 9% High Carb High Protein

25. Calcium Excretion Week 0 Week 12 Calcium excretion mmol/24hr Reference Range: 2.5-7.5mmol/24hr High Protein High Carb Calcium excretion decreased on both diets

26. Protein versus Carbohydrate and Markers of Bone Turnover Deoxypyridinoline/creatinine ratio Pyridinolone /creatinine ratio Week 0 Week 12 High Protein High Carb High Protein High Carb Both weight loss strategies associated with increased bone turnover. No effect of diet composition.

27. Haemoglobin No change Reference Range: 115-165g/L * Mean Week 0 Week 12 High Protein High Carb

28. Vitamin B12 Reference Range: 140-700pmol/L 12% increase Week 0 Week 12 13% decrease High Protein High Carb

29. 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%.

30. 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.

31. 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.

32. Questions? Booklet released in August 2003 in the Australian Women’s weekly, then as a free booklet by Meat & Livestock Australia (MLA). Book 1 published in May 2005.

33. Thank You Contact CSIRO Phone 1300 363 400 +61 3 9545 2176 Email enquiries@csiro.au Web www.csiro.au 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