1. Popular Diets Gil C. Grimes, MD Assistant Professor Family Medicine Texas A&M HSC COM Scott and White Family Medicine Residency April 9 th 2005

2. Objectives Describe the obesity rates in America Describe patients view of physicians role Describe the three basic diet types Recognize key elements for weight loss Compare the effectiveness of various dietary approaches Describe the role of exercise

3. Is the Horse out of the Barn?

4. Obesity Epidemic

5. Obesity US 1991 [Level 2b]

6. Obesity US 1992 [Level 2b]

7. Obesity US 1993 [Level 2b]

8. Obesity US 1994 [Level 2b]

9. Obesity US 1995 [Level 2b]

10. Obesity US 1996 [Level 2b]

11. Obesity US 1997 [Level 2b]

12. Obesity US 1998 [Level 2b]

13. Obesity US 1999 [Level 2b]

14. Obesity US 2000 [Level 2b]

15. Obesity US 2001 [Level 2b]

16. Texas 2001

17. What to do? Several programs available to help Commercial help (that has been studied) Weight Watcher Health Management Resources eDiets.com Take Off Pounds Sensibly OPTIFAST Do it yourself Atkins Ornish Zone South Beach

18. Patients Perception Patients surveyed in 2 Primary care practices (1) BMI <25 Wt loss is important to me 84% Wt affects my happiness 59% Wt affects my health 24% BMI 25-30 Wt loss is important to me 78% Wt affects my happiness 54% Wt affects my health 46% BMI >30 Wt loss is important to me 95% Wt affects my happiness 67% Wt affects my health 80% 1)J Fam Pract. 2001 Jun;50(6):513 Level 3

19. Patients Perception Best Method of Wt Loss for Me BMI <25BMI 25- 30 BMI >30 Exercise87%94%83% Diet87%80%79% Ref to Wt program 9%20%35% Wt loss products or pills 14 %12%20% J Fam Pract. 2001 Jun;50(6):513 Level 3

20. Patients Perception Current Doctor has helped Lost wt in past BMI <25 6% BMI 25-30 11% BMI >30 26% Lose wt in the future BMI <25 49% BMI 25-30 63% BMI >30 84% J Fam Pract. 2001 Jun;50(6):513 Level 3

21. Patients Perception Counseling on realistic goals Counseling on diets Counseling on the cause of obesity Counseling on exercise Encouragement J Fam Pract. 2001 Jun;50(6):513 Level 3

22. Basic Advice Sustainable weight loss (1) Slow steady 1-2 lbs a week 500 cal/day reduction Exercise (2)(3) Key to sustained weight loss In combination with reduced calorie synergistic effect 1)Obesity from DynaMed Level 5 2)Clinical Evidence 2001 Dec;6;43 Level 2 3)Arch Intern Med. 2000 Jul 24;160(14):2177 Level 1c

23. Basic Advice Calorie balance is the major determinant of weight loss. Diets that reduces caloric intake result in weight loss. In the absence of physical activity, the optimal diet for weight loss contains ~1400 to 1500 kcal/d, regardless of the macronutrient composition.(Level A) Popular Diets: A Scientific Review Obesity Research Vol 9 Supp 1 March 2001

25. Characterization of Diets Typical American (% energy) Fat 85 gm 35% Carbohydrates (CHO) 275 gm 50% Protein 82.5 gm 15% 2200 kcal/day Obs Research 2001 March 1;9(supl 1)1s Level 1a

26. Characterization of Diets Atkins and South Beach (% energy) High fat 94 gm 60% Low CHO <100g/d Actual 35 gm 10% High protein 105 gm 30% 1414 kcal/day Obs Research 2001 March 1;9(supl 1):1S

27. Characterization of Diets DASH and Weight Watchers (% energy) Moderate fat 40 gm 20-30% Balanced nutrient reduction diets High in CHO 218 gm 60% Moderate in protein 54 gm 15% 1450 kcal/day Obs Research 2001 March 1;9(supl 1):1S

28. Characterization of Diets Ornish and Pritkin diet (% energy) Low fat 24 gm 15% Very low fat 16 gm 10% Very high CHO 25-271 gm 65-75% Moderate protein 54-72 gm 15-20 % 1450 kcal/day Obs Research 2001 March 1;9(supl 1):1S

29. Philosophy of Low Carb High Carbohydrate intake promotes cycle Promotes increased insulin levels Result in increase Triglycerides Increased fat deposition Insulin resistance and hyperinsulinemia Reduced serotonin Decreased sense of satiety Drives more over-eating Restricted CHO produces ketosis Decreases insulin levels Promotes fat consumption Dr. Atkins New Diet Revolution

30. South Beach Angle Same Low CHO basis Introductory period of sever CHO restriction Subsequent CHO are allowed Key is low glycemic index CHO Low glycemic index foods encouraged Whole grains Vegetables Certain fruits and nuts High glycemic index food result in insulin surge Insulin surge leads to vicious cycle Choose the right fats (limit trans-fatty foods) Lean protein sources The South Beach Diet Plan

31. Atkins Decreased consumption Intake of protein and fat is self-limiting Overall reduction in caloric intake (Level A) Result in ketosis (Level B) Key factors for weight loss Duration of diet (p=0.002) Caloric restriction (p=0.03) Not carbohydrate restriction (p=0.9) JAMA 2003 Apr 9;289(14):1837 Level 1a

32. Low vs. High Carbs Low-carbohydrate diet more effective than low-fat diet at 1 year 63 obese nondiabetic patients (mean BMI 34) low-carbohydrate diet (Atkins diet) low-fat diet (1200-1500 kcal/day for women, 1500-1800 kcal/day for men) for 1 year 40% dropout rate 39% low-carbohydrate 43% low-fat group NEJM 2003 May 22;348(21):2082 Level 2

33. Low vs. High Carbs analysis using baseline data in place of current weight for dropouts (assuming regain of any weight lost) greater weight loss with low-carbohydrate diet 3 months (-6.8 kg vs.. -2.7 kg) 6 months (-7 kg vs.. -3.2 kg) but not statistically significant at 12 months (-4.4 kg vs.. -2.5 kg) NEJM 2003 May 22;348(21):2082 Level 2

34. NEJM 2003 May 22;348(21):2082 Level 1c

35. Low vs. High Carbs 120 obese volunteers with hyperlipidemia low-carbohydrate, ketogenic diet plus nutritional supplement; initially carbohydrate < 20 g/day low-fat, low-cholesterol, reduced-calorie diet; < 30% energy from fat, cholesterol < 300 mg/day, calorie deficit 500-1,000 kcal/day Both groups had exercises and group meetings Ann Intern Med. 2004 May 18;140(10):769 Level 2

36. Low vs. High Carbs Study limitations follow-up only 24 weeks high dropout rates (24% low-carbohydrate vs.. 43% low-fat group, p = 0.02, NNT 5 for tolerability) analyses both with (intent-to-treat) and without (study completers) not clearly described low-carbohydrate group (but not low-fat group) received nutritional supplement, and ketonuria tests to assess (and improve) compliance Ann Intern Med. 2004 May 18;140(10):769 Level 2

37. Low vs. High Carbs Mean weight loss at 24 weeks, comparing low-carbohydrate vs.. low-fat group -12 kg vs.. -6.5 kg (p < 0.001) -12.9% vs.. -6.7% (p < 0.001) 61% vs.. 23% completed study and had at least 10% weight loss (p < 0.001, NNT 2.6) Ann Intern Med. 2004 May 18;140(10):769 Level 2

38. Low vs. High Carbs Adverse effect significantly more common with low-carbohydrate vs.. low-fat diet constipation (68% vs.. 35%, NNH 3) headache (60% vs.. 40%, NNH 5) halitosis (38% vs.. 8%, NNH 3.3) muscle cramps (35% vs.. 7%, NNH 3.6) diarrhea (23% vs.. 7%, NNH 6.3) general weakness (25% vs.. 8%, NNH 5.9) rash (13% vs.. 0, NNH 7.7)

39. Low Fat Approach Fat-restricted diets are no more effective (and are possibly less effective) than calorie- restricted diets systematic review of randomized trials comparing fat-restricted diets vs.. control diets for weight loss in adults with BMI > 25 kg/m2 followed at least 6 months no significant differences at 6 months (4 trials), 12 months (5 trials) or 18 months (3 trials) but fat-restricted diets were associated with less weight loss in each of these comparisons Cochrane Library 2002 Issue 2:CD003640

40. Low Fat Approach Low-fat diet can promote weight loss, even in absence of caloric restriction meta-analysis of 16 studies with 1,910 subjects comparing low-fat/high-carbohydrate diet in absence of energy restriction (i.e. ad libitum, no caloric restriction) with control group of either maintenance of regular diet or diet with fat content similar to general population diets had 47% vs.. 57% fat content low-fat diet associated with weight loss of 3.2 kg, or about 7 pounds Int J Obes 2000;24;1545 Level 1a

41. The Big Comparison 160 overweight or obese adults aged 22-72 years Mean BMI 35, range 27-42 Comorbidities hypertension, dyslipidemia or fasting hyperglycemia Randomized to a diet Big encouragement for first two months Wt loss correlated with self-reported dietary adherence JAMA 2005 Jan 5;293(1):43 Level 1c

42. The Big Comparison Self Reported compliance JAMA 2005 Jan 5;293(1):43 Level 1c

43. The Big Comparison Atkins diet (carbohydrate restriction) Drop out rate 47% Wt loss 2.1kg Ornish diet (fat restriction) Drop out rate 50 % Wt loss 3.3 kg Weight Watchers diet (calorie restriction) Drop out rate 35% Wt loss 3 kg Zone diet (macronutrient balance) Dropout rate 35% Wt loss 3.2 kg JAMA 2005 Jan 5;293(1):43 Level 1c

45. Changes in HDL, CRP, Insulin JAMA 2005 Jan 5;293(1):43 Level 1c

46. Exercise

47. Role of Exercise Exercise may be more effective than diet at equivalent doses 52 obese men (mean BMI 31) RCT for 3 months Diet-induced weight loss (eating 700 kcal/day less) Exercise-induced weight loss (running off 700 kcal/day) Exercise without weight loss Control Body weight decreased by 7.5 kg (8%) in both weight loss groups and did not change in other groups Total fat decreased in both weight loss groups (p < 0.001) Average reduction 1.3 kg greater in exercise-induced weight (p = 0.03) Abdominal and visceral fat also decreased in exercise without weight loss group Ann Intern Med 2000 Jul 18;133(2):92 Level 1c

48. Role of Exercise Exercise promotes weight loss in dose- dependent fashion low amount of exercise (walking 30 minutes/day) adequate to avoid weight gain and higher amounts promote weight loss 182 sedentary, overweight men and women aged 40-65 years with mild to moderate dyslipidemia were advised to maintain existing diet for 8 months Arch Intern Med. 2004 Jan 12;164(1):31 Level 1c

49. Role of Exercise Randomized High-amount/high-intensity exercise (caloric equivalent to jogging 20 miles/week) High-amount/high-intensity exercise (equivalent to jogging 12 miles/week) Low-amount/moderate-intensity exercise (equivalent to walking 12 miles/week) 120 (66%) patients completed trial weight change +1.1 kg in control group -1.1 to -1.3 kg with low-amount exercise -3.5 kg with high-amount exercise Arch Intern Med. 2004 Jan 12;164(1):31 Level 1c

51. Take Home Points Any diet can work Must set reasonable goals Exercise is key for maintenance Provide ongoing encouragement Celebrate small successes Remember, maintenance of weight loss requires a change of lifestyle

52. Thanks