Research on Nutritional Contributors to Obesity Neal D. Barnard, M.D. Physicians Committee for...

Research on Nutritional Research on Nutritional Contributors to ObesityContributors to Obesity

Neal D. Barnard, M.D.

Physicians Committee for Responsible Medicine

5100 Wisconsin Avenue NW, Suite 400

Washington, DC 20016

Obesity in the U.S. and JapanObesity in the U.S. and JapanBMI BMI ≥≥ 30 30

Yoshiike N. Obes Rev 2002;3:183-90. Flegal KM. Int J Obesity 1998;22:39-47.

United States

Japan

%

0

5

10

15

20

25

30

1960 1971- 1976- 1988- 1999- 1974 1980 1994 2000

Overweight in U.S. and JapanOverweight in U.S. and Japan

Yoshiike N. Obes Rev 2002;3:183-90. Flegal KM. Int J Obesity 1998;22:39-47.

39.1 39.4

14.5

20.5

0

10

20

30

40

50

c.1980 c. 1990

BMI 25–29.9 kg/m2

U.S.

Japan

% %

%

%

%

Overweight and Obesity in JapanOverweight and Obesity in Japan

Yoshiike N. Obes Rev 2002;3:183-90. Yoshiike N. Asia Pac J Clin Nutr 2002;11(Suppl 8):S727-31.

24.5

20.5

14.5

2.32.010.8

0

10

20

30

1976-80 1991-95 2000

BMI 25-29.9

BMI ≥ 30

%

%

%

%% %

%

Prevalence in MenPrevalence in Men

Falling Carbohydrate Intake in Japan

Murata M. Am J Clin Nutr 2000;72(suppl):1379S-83S.

Carbohydrate (grams/day)

250

280

310

340

370

400

430

1955 1965 1975 1985 1994

Rising Fat Intake in Japan

Murata M. Am J Clin Nutr 2000;72(suppl):1379S-83S.

Fat (grams/day)

0

10

20

30

40

50

60

1955 1965 1975 1985 1994

Dietary Patterns and ObesityDietary Patterns and Obesity

Asia

Grain-Centered Diet

Obesity Is Rare

U.S., Prior to 1980

Meat-Centered Diet

Obesity Is Common

U.S. After 1980

Meat-Centered Diet + Extra

Calories

Obesity Is an Epidemic

Differential Roles for CarbohydrateDifferential Roles for Carbohydrate

Asia

Carbohydrate-rich foods are staples:

Rice

Starchy vegetables

Noodles

U.S.

Carbohydrate-rich foods are vehicles for dietary fat:

Toast and butter

Potatoes and gravy

Spaghetti and meat

Pizza and cheese

A Randomized, Controlled Study of A Randomized, Controlled Study of the Effect of a Low-Fat, Vegan Diet the Effect of a Low-Fat, Vegan Diet on Body Weight and Metabolism in on Body Weight and Metabolism in

Postmenopausal WomenPostmenopausal Women

Neal D. Barnard, M.D., Anthony R. Scialli, M.D.,Neal D. Barnard, M.D., Anthony R. Scialli, M.D.,Gabrielle Turner-McGrievy, M.S., R.D.,Gabrielle Turner-McGrievy, M.S., R.D.,Amy J. Lanou, Ph.D., Jolie Glass, M.S.Amy J. Lanou, Ph.D., Jolie Glass, M.S.

Funded by the Cancer Project of the Physicians Committee for Responsible MedicineFunded by the Cancer Project of the Physicians Committee for Responsible Medicine

MethodsMethods

• 59 overweight (BMI 26-44 kg/m59 overweight (BMI 26-44 kg/m22) ) postmenopausal womenpostmenopausal women

• Randomly assigned to a low-fat vegan or Randomly assigned to a low-fat vegan or control dietcontrol diet

• Exercise levels held constantExercise levels held constant

• Data collected at baseline and 14 weeksData collected at baseline and 14 weeks

DietsDiets

Low-Fat, Vegan DietLow-Fat, Vegan Diet• Grains, vegetables, legumes, and fruitsGrains, vegetables, legumes, and fruits• No limit on energy intake or portion sizesNo limit on energy intake or portion sizes• Excluded animal products, oils, high-fat plant foodsExcluded animal products, oils, high-fat plant foods• ~10% of energy from fat, 15% from protein, and 75% from ~10% of energy from fat, 15% from protein, and 75% from

carbohydratescarbohydrates

Control DietControl Diet• NCEP Step II guidelinesNCEP Step II guidelines• No limit on energy intakeNo limit on energy intake• Meat intake Meat intake << 6 ounces/day and fat grams 6 ounces/day and fat grams << 60 per day 60 per day• Total fat limited to 30% of energyTotal fat limited to 30% of energy• ~15% of energy from protein and > 55% from carbohydrates~15% of energy from protein and > 55% from carbohydrates

Nutrient Intake Nutrient Intake

0

50

100

150

200

250

300

Protein* Carbohydrates** Total Fat** Total Fiber**

Gra

ms Baseline-Vegan

14 Weeks-Vegan

Baseline-Control

14 Weeks-Control

* P = 0.05* P = 0.05

** P < 0.05** P < 0.05

For comparison of For comparison of low-fat vegan versus low-fat vegan versus control diet changes control diet changes (baseline to 14 (baseline to 14 weeks).weeks).

Fiber Reduces Calorie IntakeFiber Reduces Calorie Intake

Every 14 grams of fiber in the daily diet

reduces energy intake by approximately 10%.

Vegan Diet vs. NCEP Step II DietVegan Diet vs. NCEP Step II Diet

Energy (kcal)

1429

1784

1396

1762

1300

1500

1700

0 14

Weeks

Step II Diet (N=30)

Vegan Diet (N=29)


Fat (grams)

18

32

59

62

10

20

30

40

50

60

0 14

Weeks

Step II Diet (N=30)

Vegan Diet (N=29)


Carbohydrate (grams)

230

272

222

235

220

230

240

250

260

270

280

0 14

Weeks

Step II Diet (N=30)

Vegan Diet (N=29)

Changes in Body CompositionChanges in Body Compositionand Metabolism and Metabolism

-8

-6

-4

-2

0

2

4

6

Wei

ght

(kg)

**

BM

I (k

g/m

2)**

Bod

y F

at (

%)

Lea

n M

ass

(kg)

Wai

st (

in)*

*

Hip

(in

)**

RM

R/L

BM

(kca

l/d/

kg)

TE

F (

kca

l/3h

r)

Low-Fat Vegan(n=29)

Control (n=30)

** P < 0.05** P < 0.05

For comparison of For comparison of low-fat vegan versus low-fat vegan versus control diet changes control diet changes (baseline to 14 (baseline to 14 weeks).weeks).

Insulin SensitivityInsulin Sensitivity

We found an average 24% increase in insulin sensitivity in the vegan

group, with no significant change in this

variable in the Step II group.

Lanou A, Scialli AR, Turner-McGrievy G, Glass J. Unpublished Data. 2003.

Fat ContentFat Content(Percentage of Calories from Fat)(Percentage of Calories from Fat)

• Leanest beef 29%

• Skinless chicken breast 23%

• Sea trout 32%

• White tuna 16%

• Broccoli 8%

• Beans 4%

• Rice 1–5%

• Potato 1%

Casomorphins

Opiates that form as casein (milk protein) is digested.

Casomorphins

From ß-casein:

ß-casomorphin-7 Try-Pro-Phe-Pro-Gly-Pro-Ile

ß-casomorphin 5 (bovine) Tyr-Pro-Phe-Pro-Gly

ß-casomorphin 5 (human) Tyr-Pro-Phe-Val-Glu

Morphiceptin Tyr-Pro-Phe-Pro-NH2

From as1-casein:a-Casein exorphin Arg-Gly-Phe-Gin-Asn-Ala

Shah NP. Br J Nutr 2000;84(suppl 1):S3-S10.Teschemacher H. J Dairy Res 1986;53:135-8.

Super-Sizing, 1977–98 (U.S.)

Nielsen SJ. JAMA 2003;289:450-3.

Portion Sizes in Ounces

0

2

4

6

8

10

12

14

16

18

20

1977-19781989-19911994-1996

Soft Fruit Ham- Cheese- Drinks Drinks burgers burgers

U.S. Cheese Intake Has Doubled

0

5

10

15

20

25

30

35

1975 1999

Wendy’s “Cheddar Lover’s Bacon Cheeseburger”

promotion sold:

• 2.25 million pounds of cheese

• 380 tons of fat

• 1.2 tons of pure cholesterol

USDA Report to Congress on the Dairy Promotion Programs, 2000

The U.S. Government at WorkThe U.S. Government at Work

• Wendy’s “Cheddar Lover’s Bacon Cheeseburger”

• Subway’s “Chicken Cordon Bleu,” “Honey Pepper Melt”

• Pizza Hut’s “Ultimate Cheese Pizza”

• Burger King, Taco Bell

USDA Report to Congress on the Dairy Promotion Programs, 2000

The U.S. Government at WorkThe U.S. Government at Work

Dick Cooper, Vice President of Cheese Marketing, Dairy Management, Inc., at the “Cheese Forum,” December 5, 2000. USDA Report to Congress on the Dairy Promotion Programs, 2000

BMI of Meat-Eaters and Vegetarians

Appleby PN. Int J Obes 1998;22:454-60.

Oxford Vegetarian Study (age-adjusted means)

Male Meat-Eaters 23.2 kg/m2

Male Non-Meat-Eaters 22.1 kg/m2

Female Meat-Eaters 22.3 kg/m2

Female Non-Meat-Eaters 21.3 kg/m2

All participants were non-smokers.N = 2,445 meat-eaters, 2,287 non-meat-eaters

Loma Linda Study

Haddad. Am J Clin Nutr 1999;70(suppl):586S-93S.

Mean Age (years) 33.5 36.0Mean BMI (kg/m2) 25.5 20.5

Non-Vegetarians (20) Vegans (25)

Bread (servings) 10.9 11.7Vegetables (servings) 1.4 3.3Fruit (servings) 2.6 5.6Legumes (1/2 cup servings) 0.3 1.2Nuts and seeds (ounces) 0.2 0.9Meat (ounces) 6.3 0Milk (cups) 0.9 0

Diet Characteristics

Loma Linda Study

Haddad. Am J Clin Nutr 1999;70(suppl):586S-93S.

0

2

4

6

8

10

12

Bread Vegetables Fruit Legumes Nuts & Meat Milk (servings) (servings) (servings) (1/2 cup Seeds (ounces) (ounces)

servings) (ounces)

Non-Vegetarians (20) Mean Age — 33.5 yearsMean BMI — 25.5 kg/m2

Vegans (25)Mean Age — 36.0

Mean BMI — 20.5 kg/m2

=

=

Dangers of Low-Carbohydrate, High-Dangers of Low-Carbohydrate, High-Protein DietsProtein Diets

Low-Carbohydrate, High-Protein Low-Carbohydrate, High-Protein (“Atkins”) Diet(“Atkins”) Diet

Induction Phase=20 grams carbohydrate

Excluded:Fruit

Starchy vegetablesLegumes

GrainsMilk

AlcoholCaffeine

Permitted:MeatsEggs

Cheese (3-4 oz.)Nonstarchy vegetables

Salad vegetables

(3 cups maximum for all vegetables)

Low-Carbohydrate, High-Protein Low-Carbohydrate, High-Protein (“Atkins”) Diet(“Atkins”) Diet

Transition Phases (“Ongoing Weight Loss,” “Pre-Maintenance”)Slowly increase carbohydrates until weight loss stalls.

Maintenance PhaseMaintain carbohydrate restriction for life.

Nutrient Analysis of Atkins Nutrient Analysis of Atkins Sample MenusSample Menus

Nutrient intakes are based on Dr. Atkins’ New Diet Revolution (M. Evans & Co., 1999), using Nutritionist V., Version 2.0, for Windows 98 (First DataBank, Inc., Hearst Corporation, San Bruno, CA).

Atkins Atkins Induction Maintenance

Energy, kcal 1759 2173Protein, g (% energy) 143 (33%) 135 (25%)Carbohydrate, g (% energy) 15 (3%) 116 (22%)Fat, g (% energy) 125 (64%) 110 (45%)Saturated fat, g 42 38Cholesterol, mg 886 834Fiber, g 2 18

Initial Weight Loss Initial Weight Loss on Low-Carbohydrate Dietson Low-Carbohydrate Diets

Water loss:

1 pound of glycogen holds 3 pounds of water

Fiber (grams)Fiber (grams)53

25

2

18

Atkins Diet nutrient intakes are based on Dr. Atkins’ New Diet Revolution (M. Evans & Co., 1999), using Nutritionist V., Version 2.0, for Windows 98 (First DataBank, Inc., Hearst Corporation, San Bruno, CA).

Low-Fat Pyramid Atkins Atkins Vegan Induction Maintenance

Saturated Fat (grams)Saturated Fat (grams) Cholesterol (milligrams)Cholesterol (milligrams)

= Low-Fat Vegan = Pyramid = Atkins Maintenance

4

24

38

0

235

834

Protein (grams)Protein (grams)

66

93

143135

Atkins Diet nutrient intakes are based on Dr. Atkins’ New Diet Revolution (M. Evans & Co., 1999), using Nutritionist V., Version 2.0, for Windows 98 (First DataBank, Inc., Hearst Corporation, San Bruno, CA).

Low-Fat Pyramid Atkins Atkins Vegan Induction Maintenance

Effects on CholesterolEffects on CholesterolLCHP (“Atkins”) Diets Plus ExerciseLCHP (“Atkins”) Diets Plus Exercise

*Randomized controlled trials and crossover trialsBravata DM. JAMA 2003;289:1837-50.

Stanford University review, 200394 intervention trials

≤ 60 g CHO/d: No effects on TC, LDL, HDL

> 60 g CHO/d: All studies: TC ↓ 8.1 ± 1.4 mg/dl, no other effects Controlled* studies: no effect on lipids

Most studies were confounded by exercise.Most studies did not isolate effects of weight changes on lipids.

LCHP Diets and Serum CholesterolLCHP Diets and Serum Cholesterol

Serum Cholesterol

Saturated Fat

Dietary Cholesterol

Serum Cholesterol

Weight Loss

As Weight Falls, So Does CholesterolAs Weight Falls, So Does Cholesterol

Conversion forumla: Cholesterol in mg/dl x 0.02586 = mmol/LDattilo AM, Kris-Etherton PM. Am J Clin Nutr 1992;56:320-8.

Meta-analysis, Pennsylvania State University

1 lb weight TC 1 mg/dl (US units) LDL 0.4 mg/dl

1 kg weight TC 0.05 mmol/L (SI units) LDL 0.02 mmol/L

The higher the initial cholesterol level, the greater the cholesterol drop during weight loss.

Protein and Loss of Kidney Protein and Loss of Kidney FunctionFunction

Harvard Nurses’ Health Study:

Among women with mild renal insufficiency (GFR 55 to < 80 mL/min per 1.73 m2) followed for 11 years:

Every 10 g non-dairy animal protein → 1.21 mL/min per

1.73 m2 drop in GFR

Atkins Maintenance Diet suggested menu: 135 g protein per day

GFR = Glomerular filtration rate

Knight EL Ann Intern Med 2003;138:460-7.

Prevalence of Decreased Kidney FunctionPrevalence of Decreased Kidney Function

GFR = Glomerular filtration rate, mL/min per 1.73 m2

Coresh J. Am J Kidney Dis 2003;41:1-12.

Mild (GFR 60-89) Moderate (GFR 30-59)

Total population 31.2% (0.8) 4.3% (0.2)

20-39 years 13.7% (0.9) 0.21% (0.07)

40-59 years 42.4% (1.1) 1.8% (0.3)

60-69 years 53.8% (1.8) 7.1% (0.9)

70+ years 48.5% (1.1) 24.6% (1.1)






20-39 years 13.7% (0.9) 0.21% (0.07)

40-59 years 42.4% (1.1) 1.8% (0.3)

60-69 years 53.8% (1.8) 7.1% (0.9)

70+ years 48.5% (1.1) 24.6% (1.1)

With diabetes 40.4% (1.9) 14.2% (1.3)






20-39 years 13.7% (0.9) 0.21% (0.07)

40-59 years 42.4% (1.1) 1.8% (0.3)

60-69 years 53.8% (1.8) 7.1% (0.9)

70+ years 48.5% (1.1) 24.6% (1.1)

With diabetes 40.4% (1.9) 14.2% (1.3)

Hypertension, no meds 43.2% (1.5) 7.9% (0.7)

Hypertension, on meds 46.0% (1.9) 17.5% (0.9)

Most studies of high-protein diets:

Bravata DM. JAMA 2003;289:1837-50.

• Do not report effects on kidney function

• Do not track long-term effects

Calcium LossesVia Kidney (milligrams/day)

160

258 248

Regular Diet

Atkins Induction

Atkins Maintenance

Reddy ST. Am J Kidney Dis 2002;40:265-74.

Most studies of high-protein diets do not track:

Bravata DM. JAMA 2003;289:1837-50.

• calcium losses

• bone density

•long-term fracture risk

Meat Eating and Colon Cancer

1. Giovannucci E. Cancer Research 1994;54:2390-7. 2. Willett WC. N Engl J Med 1990;323:1664-72.

Risk of Colon Cancer from Eating Beef, Pork, or Lamb

Rarely or Never

≥ 5/wk, Men1

Daily, Women2

1.0

3.6

2.5

Studies of high-protein diets have been too brief to assess colon

cancer risk.

Fat and Alzheimer’s DiseaseFat and Alzheimer’s DiseaseChicago Health and Aging Project

815 healthy individuals, = 65 years old

3.9 year follow-up

Saturated fat: Highest quintile:Lowest quintile:

25.1 g/day

13.0 g/day

Risk 2.2 (CI, 1.1-4.7)

Rush-Presbyterian/St. Luke’s Medical CenterMorris MC. Arch Neurol 2003;60:194-200.

Fat and Alzheimer’s DiseaseFat and Alzheimer’s DiseaseChicago Health and Aging Project

815 healthy individuals, = 65 years old

3.9 year follow-up

Saturated fat: Highest quintile:Lowest quintile:

25.1 g/day

13.0 g/day

Risk 2.2 (CI, 1.1-4.7)

Trans fat: Highest quintile:Lowest quintile:

2.3-4.8 g/day

1.8 g/day

Risk 1.8-2.9*

n-6 fats: Highest quintile:Lowest quintile:

14.5 g/day

7.4 g/day

Risk 0.3

(CI, 0.1-0.9)

Rush-Presbyterian/St. Luke’s Medical CenterMorris MC. Arch Neurol 2003;60:194-200.*Significant for 2nd and 3rd quintiles only

Three Different ApproachesThree Different Approaches

Sugar Fruits Beans Grains Vegetables Dairy Eggs Meat Fats

Sugar Fruits Beans Grains Vegetables Dairy

Dairy Eggs Meat Fats

Atkins DietAtkins Diet

Vegan DietVegan Diet

Low-Calorie DietLow-Calorie Diet

0

19

0

5

10

15

20

25

0 10 20 30

Weight Loss: 1 lb/week

1. Barnard ND, in press. 2. Wadden TA. Ann Int Med 1993;119:688-93. 3. Westman EC. Am J Med 2002;113:30-6.

= Vegan diet, no exercise (14 weeks)1

= 1200-calorie diet (21 weeks)2

= Atkins Diet plus exercise, supplements

(26 weeks)3

0

20

0

5

10

15

20

25

0 10 20 30

0

13

0

5

10

15

20

25

0 10 20 30Weeks

Poun

ds L

ost

Weight Loss per Week (pounds)

0.8

0.9 0.9

0

0.5

1

1. Westman EC. Am J Med 2002;113:30-6; 2. Wadden TA. Ann Int Med 1993;119:688-93; 3. Barnard ND, in press.

Vegan (14 weeks)1

1200-calorie (21 weeks)2

Atkins + exercise (26 weeks)3

Long-Term Weight Loss

1. Westman EC. Am J Med 2002;113:30-6.2. Ornish D. JAMA 1998;280:2001-7.

= Vegetarian diet plus exercise2

= Atkins Diet plus exercise,

supplements1

0

5

10

15

20

25

0 1 2 3 4 50

5

10

15

20

25

0 1 2 3 4 5

The Latest Industry MythThe Latest Industry Myth“Dairy products promote weight loss.”

Evidence based solely on mouse studies or experiments using calorie-restricted diets.

Randomized trials adding dairy products to normal diets either have no effect on weight or cause weight gain.

Non-fat milk derives 55% of calories from sugar (lactose.)

Typical cheeses derive approximately 70% of calories from fat, mostly saturated fat.

The New FourFood Groups

• Grains (rice, bread, pasta, corn, oatmeal, etc.)

• Legumes (beans, peas, lentils)

• Vegetables (carrots, broccoli, spinach, squash, etc.)

• Fruits (apples, bananas, pears, cherries, etc.)

Physicians Committee for Physicians Committee for Responsible MedicineResponsible Medicine

Neal D. Barnard, M.D.

5100 Wisconsin Avenue NW, Suite 400

Washington, DC 20016

202-686-2210

[email protected]

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