1. Dietary Intervention and Recommendations in the Prevention of Obesity and Heart Disease
Nathan D. Wong, Ph.D., F.A.C.C.
Professor and Director
Heart Disease Prevention Program, University of California, Irvine

2. Dietary Effects on Lipids
Seven Countries study showed significant correlation between saturated fat intake and blood cholesterol levels
Meta-analysis of randomized controlled trials shows lowering saturated fat and cholesterol to reduce total and LDL-C 10-15%
For every 1% increase in intake of saturated fat, blood cholesterol increases 2 mg/dl
Soluble fiber intake may provide additional LDL-C response over that of a low-fat diet

3. Dietary Effects on Thrombosis
Omega-3 fatty acids have antithrombogenic and antiarrhythmic effects, decreased platelet aggregation, and lower triglycerides
Eskimos’ cold water fish diet associated with prolonged bleeding times and lower rates of MI; similar findings in Japan, Netherlands, and England
Lyon Diet-Heart Study reported increased survival following Mediterranean diet with fish and high in linolenic acid (no lipid differences seen).

4. Associations between the percent of calories derived from specific foods and CHD mortality in the 20 Countries Study*
Food Source Correlation Coefficient†
Butter
All dairy products
Eggs
Meat and poultry
Sugar and syrup
Grains, fruits, and starchy
and nonstarchy vegetables
*1973 data, all subjects. From Stamler J: Population studies. In Levy R: Nutrition, Lipids, and CHD. New York, Raven, 1979.
†All coefficients are significant at the P<0.05 level.

5. Men participating in the Ni-Hon-San study*
Residence
Japan Hawaii California
Age (years)
Weight (kg)
Serum cholesterol (mg/dL)
Dietary fat (% of calories)
Dietary protein (%)
Dietary carbohydrate (%)
Alcohol (%)
5-yr CHD mortality rate
(per 1,000)
*Data from Kato et al. Am J Epidemiol 1973;97:372. CHD, coronary heart disease.

6. Epidemiologic studies*
Populations on diets high in total fat, saturated fat, cholesterol, and sugar have high age-adjusted CHD death rates as well as more obesity, hypercholesterolaemia, and diabetes
The converse is also true
What is the evidence for dietary intervention studies?
*Results from Seven Countries, 18 countries, 20 countries, 40 countries,
and Ni-Hon-San Studies

7. Oslo Diet Heart Study 412 men with CHD, 5 year study
Treatment group randomized to low saturated fat (8.4% of calories), low cholesterol (264 mg/day), high polyunsaturated fat (15.5%) diet
Serum cholesterol reduced 14%
33% reduction in MI, 26% decrease in CHD mortality
Dietary counseling every 3 months
Leren et al. Acta Med. Scand 1966; 466:1.

8. Los Angeles VA study 846 men in Veterans Home, 5-8 years
Groups randomized to diets in which 2/3 of fat given either as vegetable oil (corn, cottonseed, safflower, soybean) or animal fat
Saturated fat 11% vs. 18%, polyunsaturated fat 16% vs. 5% of calories
31% decrease in CVD endpoints
Dayton et al. Circulation 1969; 40:1.

9. Lyon Diet Heart study 302 men and women with CHD
Treatment group randomized to low saturated fat, high canola oil margarine (5% alpha linolenic, 16% linoleic, and 48% oleic acid, also 5% trans)
46 month follow-up
65% lower CHD death rate in treatment group (6 vs. 19 death)
de Lorgeril et al. Circulation 1999; 99:

10. Stanford Coronary Risk Intervention Project (SCRIP)
300 men and woman with CHD, baseline and 4 year follow-up angiograms
Randomized to <20% fat, <6% saturated fat, <75 mg cholesterol/day, and exercise (Rx group) vs usual care
LDL-C and TG decreased 22% and 20%, and HDL-C increased 20%
Rx group had 47% less progression than control group, P<0.02
Haskell et al. Circulation 1994; 89: Quinn et al. JACC 1994; 24:

11. U.S. Diabetes Prevention Project
3234 subjects with BMI > 34 kg/m2
Placebo, metformin, and lifestyle modification
Lifestyle modification goal > 7% weight loss with diet and exercise ( 150 min / week)
New onset diabetes: 11% placebo, 7% metformin, 4.8% lifestyle group
NEJM 2002

12. Finnish Diabetes Prevention Study
522 overweight subjects; Intervention group - met with dietician 4 x /yr and supervised exercise vs control group (pamphlet)
Goals: 1) 5 lb wt loss 2) 15gm of fiber/1000 cal 3) < 30% fat 4) < 10% saturated fat 5) 30 minutes of exercise /day
Intervention group met 4/5 goals 0% new diabetes, vs control group met 0 goals 32% new diabetes
NEJM 2001

13. Cardiovascular Effects of Treating Overweight/Obesity (1998 NHLBI Obesity Guidelines)
Lower elevated BP in overweight and obese persons with high blood pressure (45 trials)
Lower elevated total and LDL-cholesterol and triglycerides and increase HDL-cholesterol (22 trials)
Lower elevated blood glucose levels in overweight and obese persons with diabetes (17 trials)

14. Summary of Dietary Trials for Weight Loss (1998 NHLBI Obesity Guidelines)
48 acceptable RCTs showing an average weight loss of 8% of initial body weight can be obtained over 3-12 months
Weight loss effects decrease in abdominal fat; low-fat diets with targeted caloric reduction promote greater weight loss
Very low calorie diets promote greater initial weight loss, but similar effects after one year
No improvement in CVD fitness measured by V02max in those not incorporating physical activity with dietary therapy

15. Homocysteine: Role in Atherogenesis
Linked to pathophysiology of arteriosclerosis in 1969
CVD patients have elevated levels of plasma homocysteine
May cause vascular damage to intimal cells
Elevated levels linked to:
genetic defects
exposure to toxins
diet
Increased dietary intake of folate and vitamin B6 may reduce CVD morbidity and mortality
McCully KS. Am J Pathol. 1969;56:
McCully KS. JAMA. 1998;279:
Rimm EB et al. JAMA. 1998;279:

16. Benefits of fish oil supplementation
In the Diet and Reinfarction Trial (DART) in 2033 men with CHD increased intake of fish or use of 2 fish oil caps/day reduced CHD mortality 29% over 2 years
In GISSI men and woman with CHD use of 1 gr. of n-3 PUFA decreased CVD events including mortality 15%
Lancet 1989; 2; , and 1999; 345:

17. Nuts, Soy, Phytosterols, Garlic
Nurses’ Health Study: five 1oz servings of nuts per week associated with 40% lower risk of CHD events
Metaanalysis of 38 trials of soy protein showed 47g intake lowered total, LDL-C, and trigs 9%, 13%, and 11%
Phytosterol-supplemented foods (e.g., stanol ester margarine) lowers LDL-C avg. 10%
Meta-analysis of garlic studies showed 9% total cholesterol reduction (1/2-1 clove daily for 6 months).

18. Controversy regarding efficacy of Soy Protein

19. 2006 AHA Statement on Diet

20. Goals for CVD Risk Reduction

21. AHA 2006 Diet and Lifestyle Recommendations

22. Tips to Implementation of Diet and Lifestyle Interventions

23. Food Choices and Preparation Tips

24. Examples of Dietary Patterns Consistent with AHA Dietary Goals at 2000 Calories

25. Trans Fatty Acids

26. Therapeutic Lifestyle Changes in LDL-Lowering Therapy: Major Features
Saturated fats <7% of total calories
Dietary cholesterol <200 mg per day
Plant stanols/sterols (2 g per day)
Viscous (soluble) fiber (10–25 g per day)
Weight reduction
Increased physical activity

27. Therapeutic Lifestyle Changes Nutrient Composition of TLC Diet
Nutrient Recommended Intake
Saturated fat Less than 7% of total calories
Polyunsaturated fat Up to 10% of total calories
Monounsaturated fat Up to 20% of total calories
Total fat 25–35% of total calories
Carbohydrate 50–60% of total calories
Fiber 20–30 grams per day
Protein Approximately 15% of total calories
Cholesterol Less than 200 mg/day
Total calories (energy) Balance energy intake and expenditure to maintain desirable body weight/ prevent weight gain

28. A Model of Steps in Therapeutic Lifestyle Changes (TLC)
Visit 2
Evaluate LDL response
If LDL goal not achieved, intensify LDL-Lowering Tx
Visit 3
Evaluate LDL response
If LDL goal not achieved, consider adding drug Tx
Visit N
Visit I
Begin Lifestyle Therapies
6 wks
6 wks
Q 4-6 mo
Monitor Adherence to TLC
Emphasize reduction in saturated fat & cholesterol
Encourage moderate physical activity
Consider referral to a dietitian
Reinforce reduction in saturated fat and cholesterol
Consider adding plant stanols/sterols
Increase fiber intake
Consider referral to a dietitian
Initiate Tx for Metabolic Syndrome
Intensify weight management & physical activity
Consider referral to a dietitian

29. Steps in Therapeutic Lifestyle Changes (TLC)
First Visit
Begin Therapeutic Lifestyle Changes
Emphasize reduction in saturated fats and cholesterol
Initiate moderate physical activity
Consider referral to a dietitian (medical nutrition therapy)
Return visit in about 6 weeks

30. Steps in Therapeutic Lifestyle Changes (TLC) (continued)
Second Visit
Evaluate LDL response
Intensify LDL-lowering therapy (if goal not achieved)
Reinforce reduction in saturated fat and cholesterol
Consider plant stanols/sterols
Increase viscous (soluble) fiber
Consider referral for medical nutrition therapy
Return visit in about 6 weeks

31. Steps in Therapeutic Lifestyle Changes (TLC) (continued)
Third Visit
Evaluate LDL response
Continue lifestyle therapy (if LDL goal is achieved)
Consider LDL-lowering drug (if LDL goal not achieved)
Initiate management of metabolic syndrome (if necessary)
Intensify weight management and physical activity
Consider referral to a dietitian

32. Dietary Approaches to Stop Hypertension (DASH)
Diet high in fruits and vegetables and low-fat dairy products lowers blood pressure (11 mmHg SBP/ 5 mmHg DBP lower than traditional US diet), including more than a sodium-restricted diet
Recommends 7-8 servings/day of grain/grain products, 4-5 vegetable, 4-5 fruit, 2-3 low- or non-fat dairy products, 2 or less meat, poultry, and fish.
NEJM 1997; 366:

33. Dietary fats* Fat SFA MUFA PUFA Cholesterol Canola oil† 6 62 31 0
Corn oil
Olive oil
Palm oil
Safflower oil
Soybean oil†
Sunflower oil
*Values for SFA, MUFA, and PUFA represent percentage of total fat calories, whereas those for cholesterol
are expressed as mg per tablespoon. SFA is the sum of lauric, myristic, palmitic, and stearic acids.
†Contain a considerable amount (>5%) of alpha-linolenic acid.
‡Some are high in trans fatty acids: vegetable shortening>margarine fat>animal fat shortening>butter fat.
SFA, saturated fatty acids; MUFA, monounsaturated fatty acids; PUFA, polyunsaturated fatty acids.

34. USDA FOOD PYRAMID Daily Food Intake Recommendations
I servings of bread, cereal, rice or pasta
1 serving is 1 slice of bread, 1 ounce of ready to eat cereal,
or a ½ cup of cereal, rice, or pasta.
II servings of vegetables
1 serving is 1 cup of leafy vegetables, a ½ cup
of other vegetables (cooked or chopped), or 3/4 cup of vegetable juice.
III servings of fruit
1 serving is 1 apple, banana, or orange, a ½ cup of chopped,
cooked, or canned fruit, or 3/4 cup of fruit juice.
IV servings of milk, yogurt, or cheese
1 serving is 1 cup of low fat or skimmed milk or yogurt,
1½ ounces of natural cheese, or 2 ounces of processed cheese.
V servings of meat, poultry, fish, dried beans, or nuts
1 serving is 2-3 ounces of lean meat,
poultry (white meat without skin), or fish, or 1 cup of beans or nuts.
VI. Use fats, oils, and sugars (including syrup) sparingly

35. Recommendations for CHD risk reduction and weight loss
Decrease calories and increase energy expenditure
Decrease saturated fat and cholesterol (animal fats)
Increase essential fatty acids, especially n-3 (alpha-linolenic or fish oil-EPA/DHA)
Decrease sugar intake and increase intake of vegetables, fruits and grains
Decrease hydrogenated fat and tropical oil intake
Replace butter with soft no trans margarine or oil (canola and soybean) or plant sterol margarine
Decrease caloric density and increase fibre

36. Dietary Approaches: Dean Ornish
Reversal Diet: 10% fat, 70-75% carbohydrate, 15-20% protein, 5 mg cholesterol/day, excludes all animal products (including seafood) except nonfat milk and yogurt, also excludes high-fat vegetarian foods, including oils, nuts, seeds, and avocados.
Prevention Diet: Allows up to twice as much fat as the Reversal Diet, as long as blood cholesterol remains at 150 or less, allows meat and seafood, substitutes egg whites for yolks, use of canola oil.

37. Lifestyle Heart Trial 41 male and female CHD patients
Randomized to <10% fat diet, exercise and meditation (Rx group) vs. Step 1 diet
At one year 37% LDL-C reduction, 22% weight loss, and 1.8 % regression in Rx group vs 2.3% progression in control group (quantitative coronary angiography)
At 5 years 20% LDL-C reduction, 3.1% regression in Rx group vs 11.8% progression in control group (n=35)
Ornish et al. Lancet 1990; 336: , and JAMA 1998; 280:

38. Dietary Approaches: Zone/Soy Zone
Premise is to reduce insulin levels and stabilize glucose control by limiting starchy carbohydrates, emphasize low-density carbohydrates.
Emphasis on protein (avg. 75g/day for women and 100 g/day for men) (one-third of plate) (soy protein products for Soy Zone) and carbohydrates (primarily from vegetables, fruits to a lesser extent). Allows limited monounsaturated fats.
Metaanalysis of clinical trial on soy protein (avg. 47g/day) showed reduction in total cholesterol of 9%, LDL-C 13%, and triglycerides 11% (NEJM 1995; 333: )

39. Dietary Approaches: Atkins
Intended to correct unbalanced metabolism by restriction of carbohydrates to reduce insulin production and conversion of excess carbohydrates into stored body fat
Induction diet limits carbohydrate intake to 20 gms/day (e.g., 3 cups of salad veg or 2 cups salad + 2/3 cup cooked vegs) to induce ketosis/ lypolysis. Maintenance diet gms/day.
Pure proteins, fats, and protein/fat allowed (all meats, fish, foul, eggs, cheese, veg oils, butter)
Most carbohydrates are not allowed--fruits, bread, grains, starchy vegs, or dairy products.

40. Data on Atkins and Zone diets
Medline analysis 2001
No large scale (>50 subjects) long term (>6months) follow-up studies could be identified with weight loss, cardiovascular risk assessment or clinical outcome data

41. Pritikin Lifestyle Program
3-week residential program with exercise and ad libitum low fat (<10% of calories) plant based diet
4566 men and woman
Mean LDL-C reduction 25% in men and 20% in woman
Significant reductions in TG and HDL-C
Significant 3.2% reduction in body weight
Limited long-term follow up
Barnard et al. Arch Intern Med 1991;151:

42. Very Low Fat Diets: AHA Science Advisory (Circ. 1998; 98: 935-39)
Diets <15% cal from fat, 15% protein, 70% carbohydrates; shown to be associated with lower CVD rates.
Reducing fat intake from 35-40% to 15-20% reduces total and LDL-C 10-20%, but can increase TG and lower HDL-C. Long-term effects after weight stabilization not known.
Effect on nutrient adequacy and density not well-known. Concern on meeting essential fatty acid requirements, esp. in youth (low-fat diets not recommended <2 yrs).
Selected, high-risk persons with elevated LDL-C or CVD may benefit with proper supervision. Advice needed for optimal substitution of complex carbohydrates for fat.
Clinical trials needed to show if there is added benefit

43. Barriers to Dietary Adherence
Restrictive dietary pattern
Required changes in lifestyle and behavior
Symptom relief may not be noticable
Interference of diet with family/personal habits
Cost, access to proper foods, preparation effort
Denial or perceiving disease not serious
Poor understanding of diet/disease link
Misinformation from unreliable sources

44. Strategies for Maintaining Dietary Change
Tailoring diet to patient’s needs
Using social support inside and outside healthcare setting
Providing patient and caretaker with skills and training
Ensuring an effective patient-counselor relationship
Evaluation, follow-up, and reinforcement