MANAGEMENT OF OBESITY AND RELATED CONDITIONS:Does Diet Composition Matter?

Lisa M. Neff, MD, MSAssistant Professor of EndocrinologyNorthwestern UniversityPresented at Obesity 2010, San Diego, CA

Objectives

To review the evidence regarding the effects of dietary macronutrient composition on weight loss outcomes.

To review the evidence regarding the effects of diet composition on metabolic parameters in the absence of weight loss. the DASH diet the low glycemic index diet

DIETARY MACRONUTRIENTCOMPOSITION AND WEIGHT LOSS

Expected mean body weight over time, by diet group

Yancy W S et al. Ann Intern Med 2004;140:769-777

©2004 by American College of Physicians

Low fat -6.5 kg

Low carb -12.0 kg

Dietary Macronutrient Composition and Weight Loss: Positive Studies

Study n Duration

Mean Weight Change by Diet

Shai I, NEJM, 2008

322 2 yr LC - 4.7 kgMed - 4.4 kgLF - 2.9 kg

Gardner CD, JAMA, 2007

311 1 yr LC (Atkins) - 4.7 kgHP (Zone) -1.6 kgLF (Ornish) - 2.2 kgLF (LEARN) - 2.6 kg

LC = low carb, Med = Mediterranean, LF = low fat, HP = high protein

Gardner, C. D. et al. JAMA 2007;297:969-977.

Weight Change Relative to Baseline

Predicted absolute mean change in body weight for participants in the low-fat and low-carbohydrate diet groups, based on a random-effects linear model.

Error bars represent 95% CIs.

Foster G D et al. Ann Intern Med 2010;153:147-157

©2010 by American College of Physicians

Dietary Macronutrient Composition and Weight Loss: Negative Studies

Study n Duration

Mean Weight Change by Diet

Foster GD, Ann Intern Med, 2010

307 2 yr LC - 6.3 kgLF - 7.4 kg

Sacks FM, NEJM, 2009

811 2 yr LF/SP LF/HP HF/SP - 3.0 to - 3.6 kgHF/HP

Brinkworth GD, AJCN, 2009

107 1 yr LC -13.1 kgLF - 11.6 kg

LC = low carb, LF = low fat, HF = high fat, SP = standard protein, HP = high protein

Dietary Macronutrient Composition and Weight Loss: Negative Studies

Study n Duration

Mean Weight Change by Diet

Frisch S, Cardiovasc Diabetol, 2009

200 1 yr LC -5.8 kgLF -4.3 kg

Layman DK, J Nutr, 2009

130 1 yr HP - 9.3 kgLF - 7.4 kg

Keogh JB, Br J Nutr, 2007

73 1 yr HM -7.6 kgHP - 4.8 kg

LC = low carb, HP = high protein , LF = low fat, HM = high MUFA

Dietary Macronutrient Composition and Weight Loss: Negative Studies

Study n Duration

Mean Weight Change by Diet

Ebbeling CB, JAMA, 2007

73 18 mo LG = LF (~ - 2 kg)

Das SK, AJCN, 2007

34 1 yr LG -7.8%LF – 8.0%

Dansinger ML, JAMA, 2005

160 1 yr LC (Atkins) - 2.1 kgHP (Zone) - 3.2 kgLF (Wt Watchers) - 3.0 kgLF (Ornish) -3.3 kg

LG = low glycemic load, LC = low carb, HP = high protein, LF = low fat

Dietary Macronutrient Composition and Weight Loss: Negative Studies

Study n Duration

Mean Weight Change by Diet

Stern L, Ann Intern Med, 2004

132 1 yr LC - 5.1 kgLF - 3.1 kg

Due A, Int J Obes, 2004

50 1 yr HP/LF - 6.2 kgSP/LF - 4.3 kg

Foster GD, NEJM 2003

63 1 yr LC - 4.4%LF - 2.5%

HP = high protein, LF = low fat, SP = standard protein, LC = low carb

Dietary Macronutrient Composition and Body Composition ChangesPositive StudiesHP > LF Body fat:

Layman DK et al., J Nutr, 2009

Abdominal fat, waist circ: Due A, Int J Obes, 2004

LC > LF Waist circ:

Frisch S, Cardiovasc Diabetol, 2009

Negative StudiesLC = LF Foster GD, Ann Intern

Med, 2010 Brinkworth GD, AJCN

2009

HM = HP Keogh JB, Br J Nutr, 2007

LG = LF Ebbeling CB, JAMA, 2007 Das SK, AJCN, 2007

HP = high protein, LF = low fat, LC = low carb, HM = high MUFA, LG = low glycemic load

Individual percent weight changes at 2 year for 270 subjects completing the DIRECT intervention, comparing a low fat diet, a Mediterranean diet, and a low carb diet. From Greenberg I, J Am Coll Nutr, 2009

Dansinger, M. L. et al. JAMA 2005;293:43-53.

One-Year Changes in Body Weight as a Function of Dietary Adherence Level

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Weight Loss Outcomes May Be Influenced by Metabolic Profile Ebbeling CB, JAMA, 2007

Subjects with high insulin secretion after an OGTT lost more weight (and more fat) on a low GL diet than on a standard LF diet. Those with low insulin secretion lost the same with a low GL or LF diet.

Pittas A, Diabetes Care, 2005. Subjects with high insulin secretion after an OGTT lost

more weight on a HP, low GL diet than on a high carb, high GL diet. Those with low insulin secretion tended to lose more weight with a high GL diet (NS).

Cornier MA, Obes Res, 2005. Insulin sensitive women lost more weight with a LF diet,

whereas insulin resistant women lost more weight with a HP diet.

However…

Other studies suggest low fat, low carb, and low glycemic load diets are equally effective for long-term weight loss in patients with type 2 diabetes: Davis NJ, Diabetes Care, 2009 Wolever TM, AJCN, 2008 Brinkworth GD, Diabetologia, 2004

DIETARY COMPOSITION AND METABOLIC PARAMETERSIN THE ABSENCE OF WEIGHT LOSS

The DASH Diet

High in fruits and vegetables (typically 10 servings/day or more), whole grains, and low fat dairy products(2-3 servings/day or more)

Moderate amounts of nuts, beans, fish and poultry

Limited red meat, fried foods, and sweets Low in cholesterol, saturated fat, sugars,

and sodium High in calcium, magnesium, potassium,

vitamins, phytochemicals, and fiber

The DASH Diet

High in fruits and vegetables (typically 10 servings/day or more), whole grains, and low fat dairy products(2-3 servings/day or more)

Moderate amounts of nuts, beans, fish and poultry

Limited red meat, fried foods, and sweets Low in cholesterol, saturated fat, sugars,

and sodium High in calcium, magnesium,

potassium, vitamins, phytochemicals, and fiber

The DASH Diet

At weight stability, the DASH diet: Lowers blood pressure in normotensive and

hypertensive adults (Appel, NEJM 1997, Sacks, NEJM 2001)

Reduces LDL cholesterol (Obarzanek, AJCN 2001)

But, it may also: Reduce HDL cholesterol, like other low-fat

diets (Obarzanek, AJCN, 2001) Increase TG in some patients, like other high

carbohydrate diets (Erlinger, Circulation, 2003)

The DASH Diet

Weight loss studies suggest the diet: May reduce fasting glucose and improve

insulin sensitivity more than standard weight loss diets (Azadbakht, Diabetes Care 2005, Ard, Diabetes Care 2004)

May reduce inflammatory markers such as C-reactive protein and increase levels of adiponectin (Lien, Obesity, 2006)

May increase antioxidant capacity and reduce oxidative stress (Lopes, Hypertension, 2003)

Ludwig, D. S. JAMA 2002;287:2414-2423.

Foods with similar carbohydrate content can affect blood glucose levels differently

Glycemic Index

Potato Instant oatmeal White bread Watermelon

Basmati rice Stoneground whole wheat

bread Raisins Pineapple

Kidney beans Chocolate ice cream Oatmeal made with steel-

cut oats Spaghetti, al dente

Low Glycemic Index Diets

Without weight loss, low GI diets: Reduce postprandial glucose levels in

normal individuals and people with diabetes (Ludwig, JAMA, 2002)

Produce modest improvements in HbA1c in patients with diabetes (Thomas D, Cochrane Database Syst Rev, 2009)

May or may not affect insulin sensitivity

Low Glycemic Index Diets

Without weight loss, low GI diets may:

increase HDL (Luscombe, EJCN, 1999)

reduce inflammatory markers such as IL-1β and IL-6 (Kallio, AJCN, 2008)

increase antioxidant capacity (Botero, Obesity, 2009)

Low Glycemic Index Diets

With weight loss:In overweight and obese adults (n=39), a low GI diet produced greater improvements in the following, as compared to a low fat diet (despite identical weight loss of 10%) :

insulin resistanceTGCRP blood pressure(Pereira MA, JAMA, 2004)

Summary

Dietary macronutrient composition does not influence weight loss outcomes in the general population.

Dietary adherence influences weight loss outcomes.

Other factors (such as insulin resistance) might influence weight loss outcomes.

Dietary micronutrient and macronutrient composition may influence metabolic parameters in the absence of weight loss.

Future Directions

Wt Stable on Western

DietTesting

#1

Wt Stable on Western

Diet

Wt Stable on DASH Diet

Wt Stable on Low GI

DietTesting #2 Testing #2 Testing #2

Subjects: n=39, ages 18-65, with insulin resistance and the metabolic syndrome.

Outcomes: insulin sensitivity, glycemic control, lipids, blood pressure, inflammatory markers

2 weeksInpatient

2 weeksInpatient