The Atkins Diet

1. The Atkins Diet Cristi Howe, M. D.

2. Obesity • Excess body fat relative to lean body mass • Associated with obstructive sleep apnea, hypertension, cardiovascular disease, stroke, diabetes, osteoarthritis, & death • 325,000 deaths/year • $39 - $52 billion/year • Measured by Body Mass Index (BMI) • BMI = weight (kg)/height2 (m2) • Healthy 18.5 – 24.9 • Overweight 25 – 29.9 • Obese 30 + • Between 1991-2001, the prevalence of obese U. S. adults has increased from 12% to 21%. • Currently, 44 million U. S. adults are obese.

3. Obesity Trends* Among U.S. AdultsBRFSS, 1985 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

4. Obesity Trends* Among U.S. AdultsBRFSS, 1986 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

5. Obesity Trends* Among U.S. AdultsBRFSS, 1987 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

6. Obesity Trends* Among U.S. AdultsBRFSS, 1988 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

7. Obesity Trends* Among U.S. AdultsBRFSS, 1989 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

8. Obesity Trends* Among U.S. AdultsBRFSS, 1990 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

9. Obesity Trends* Among U.S. AdultsBRFSS, 1991 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

10. Obesity Trends* Among U.S. AdultsBRFSS, 1992 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

11. Obesity Trends* Among U.S. AdultsBRFSS, 1993 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

12. Obesity Trends* Among U.S. AdultsBRFSS, 1994 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

13. Obesity Trends* Among U.S. AdultsBRFSS, 1995 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

14. Obesity Trends* Among U.S. AdultsBRFSS, 1996 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

15. Obesity Trends* Among U.S. AdultsBRFSS, 1997 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

16. Obesity Trends* Among U.S. AdultsBRFSS, 1998 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

17. Obesity Trends* Among U.S. AdultsBRFSS, 1999 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

18. Obesity Trends* Among U.S. AdultsBRFSS, 2000 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

19. Obesity Trends* Among U.S. AdultsBRFSS, 2001 Source: Mokdad A H, et al. J Am Med Assoc1999;282:16, 2001;286:10.

20. Case 55 year old female with PMH of hypertension and hyperlipidemia. She does have a family history of premature heart disease and uses tobacco. Over the past year she has developed progressive weight gain. Her BMI is currently 32. Recently, she has exhibited mild glucose intolerance with fasting sugars between 115 – 120. You suggest that she needs to lose weight to prevent the onset of diabetes…………………..... ………………..She asks HOW?

21. Law of Thermodynamics • “The energy of an isolated system is constant and any exchange of energy between a system and its surroundings must occur without the creation or destruction of energy.” • Calories = units of energy • Carbohydrate 4 kcal/gram • Protein 4 kcal/gram • Fat 9 kcal/gram • Weight loss results from decreased caloric intake and increased caloric expenditure. • 3500 kcal = 1 pound

22. U.S. Department of Agriculture

23. American Heart Association Calories Weight Maintenance = Weight (lbs) * 15 (2300 calories) Carbohydrate 50 – 60 % caloric intake (345 g) Limit simple carbohydrates, 20-30 g/day fiber Protein 10 - 20 % caloric intake (58 g) Fat < 30% caloric intake (76 g) 10% unsaturated, 10% polyunsaturated, <10% saturated Cholesterol < 300 mg/day

24. “… You stopped eating red meat, cooked egg-white-only omelettes with no shortening in a Teflon pan, removed the skin from chicken, ate your baked potato without butter or sour cream and consumed lots of pasta. Frozen yogurt, fruit, and sherbert served as dessert. Your breakfast consisted of oatmeal and skim milk or else granola and a banana. A typical lunch was white-meat turkey on a roll and a generous salad, hold the dressing.”

25. The Atkins Diet • Low-carbohydrate • High-fat • High-protein • NO caloric restriction

26. The Atkins Diet • “It is the most successful weight loss and weight maintenance program of the last quarter of the twentieth century. It works an astonishing proportion of the time for the vast majority of men and women.” • “It can positively impact the lives of people facing the risks of diabetes, heart disease, and hypertension.”

27. Prevalence of Overweight U. S. Adults

28. Physiology of Metabolism

29. Physiology of Metabolism

30. Physiology of Metabolism

31. Physiology of Metabolism

32. Physiology of Metabolism

33. The Atkins Diet • Avoids glucose surges and insulin release • Avoids anabolic processes that produce glycogen and fat • Prevents reactive hypoglycemia • Curtails insulin resistance • Improves blood pressure • Decreases triglycerides

34. The Atkins Diet • Stimulates glucagon and catabolic processes • Glycogenlysis • Gluconeogenesis • Fat breakdown • Ketones serve as the primary source of energy • Ketosis produces anorexic effect • Fat stimulates cholecystokinin and delayed gastric emptying creating satiety

35. CriticsAmerican Diabetic AssociationAmerican Heart Association • Ketone accumulation • Abnormal insulin metabolism • Impaired kidney function • Postural hypotension • Fatigue • Constipation • Nephrolithiasis • Hyperlipidemia

36. The Atkins Diet • Pre-evaluation • Blood pressure • Complete metabolic profile, uric acid, TSH • Glucose tolerance test with associated insulin levels • Medications • Diuretics • Antihypertensives • Diabetes medications • Contraindications • Pregnancy, Renal failure (Cr > 2.4)

37. The Atkins Diet • Induction • Eat liberal amounts of calories every six hours until satiated • Limit daily carbohydrate intake to < 20 grams • 3 cups of salad vegetables • 2 cups of salad & 1 cup of “acceptable” vegetables • NO fruit, bread, pasta, grains, starchy vegetables, nuts, dairy (except cheese, butter, cream) • No alcohol, caffeine, or aspartame • 64 ounces of water/day • Multivitamin supplementation

38. The Atkins Diet • Induction • 2 week period to stimulate ketosis • 6 - 10 pound weight loss over two weeks • Water loss over the first 7 – 10 days • Fatigue and withdrawal symptoms over 1st few days • Constipation secondary to low fiber intake

39. The Atkins Diet • Ongoing Weight Loss • Increase daily carbohydrate intake 5 grams/week until you reach critical carbohydrate level of losing • Only low glycemic index food allowed (Glucose = 100) • Once you reach CCLL decrease daily carbohydrate intake by 5 gram • Continue until 5 – 10 pounds shy of goal weight

40. The Atkins Diet • Pre-maintenance • Increase daily carbohydrate intake by 10 grams/week until goal weight • Maintain carbohydrate level for one month • Increase carbohydrate level until weight gain • Then decrease slightly to critical carbohydrate level of maintenance (CCLM)

41. The Atkins Diet • Lifetime Maintenance • Maintain CCLM • Average metabolic resistance: 40 – 60 grams/day • Regular exerciser: >90 grams/day • Allow a 5 pound weight variation • If weight exceeds the upper limit, return to induction

42. Early Studies • 1863 Banting Diet • 1953 Pennington “Treatment of Obesity with Calorically Unrestricted Diets” • Limit carbohydrate intake to < 60 grams/day • Avoid production of pyruvic acid • Prevents fat synthesis • Stimulates fat breakdown

43. Yukin, et al. • Study design – 2 week pre-post study • 6 overweight adults • Fixed carbohydrate composition (< 50 g/d) • Unlimited calories, protein, & fat • Results • All subjects lost weight, between 2 – 9 pounds. • All subjects decreased caloric intake by 13 – 55%. • Conclusion • Subjects self-select fewer calories when consuming a high fat diet. • Weight loss is inversely proportional to caloric intake.

44. Kekwick, et al. • Study design I – randomized cross-over • 6 obese adult (>35% MLS) inpatients • Fixed diet composition (47% C, 33% F, 20% P) • Variable caloric intake (2000, 1500, 1000, 500) • Alternating every 7 – 9 days • No “wash-out” period • Urea-dilution method to determine fluid losses • Moderate exercise permitted • Results • Decreasing caloric intake resulted in weight loss. • 30 – 50% of weight loss was water as calculated by urea-dilution method.

45. Kekwick, et al.

46. Kekwick, et al. • Study design II – randomized cross-over • 14 obese adult (>35% MLS) inpatients • Fixed caloric intake (1000 calories) • Variable diet composition (90% C, 90%F, 90%P) • Alternating every 5 – 9 days • No “wash-out” period • Moderate exercise permitted • Results • Weight loss was most rapid with 90% fat intake. • No weight loss occurred with high carbohydrate diet. Some mild weight gain was observed.

47. Kekwick, et al.

48. Kekwick, et al. • Study design III – pre-post study • 5 obese adult (>35% MLS) inpatients • Well-balanced 2000 calorie diet for 7 days • Caloric intake increased to 2600 and carbohydrate intake decreased to minimal for variable durations (4-14 days) • Moderate exercise permitted • Results • Weight loss occurred on high calorie, low- carbohydrate diet (1 – 2.6 kg).

49. Kekwick, et al. • Conclusions • Weight loss is inversely proportional to caloric intake. • Greater weight loss occurs with high fat diets. • Fat digestion stimulates more caloric expenditure. • Weaknesses • Variable study durations • Questionable subject compliance

50. Yang, et al. • Study design – randomized cross-over • 6 obese adult (>92% desirable weight) inpatients • Fasting; 800 calorie/10 g CHO; 800 calorie/90 g CHO formulas • Alternating every 10 days • 5 day “wash-out” on 1200-calorie balanced diet • Energy-Nitrogen Balance • Energy loss = caloric intake – energy expenditure • Energy expenditure measures by indirect calorimetry • resting, lying awake, sitting, standing, walking determined 3 x during every 5 day interval • collectable excreta • Protein loss = nitrogen loss * 6.25 • Fat loss = (energy loss – (nitrogen loss * 25.6))/9.3 • Water loss = weight loss – (protein loss + fat loss)