Mel i ta Schuster, DOMike LaFonta ine , PhD

Marian Univers i tyCo l lege o f Osteopath ic Medic ine

Deconstructing Diets

Why do we care about diet?

Obesity is a risk factor in most of the leading causes of death in the US.

Diet and Exercise influence many of these as well.

Top Ten Causes of Death in the US Heart Disease Cancer Chronic Respiratory Diseases Accident Alzheimer’s Disease Diabetes Kidney Disorders Influenza and Pneumonia Suicide

From CDC

Obesity in the United States

1985

-6 States with greater than 10% obesity

1994

-First year with data from all 50 states

-50 states with greater than 10% obesity

-No state with greater than 20% obesity

2005

-Only Colorado with less than 20% obesity

2009

-Last year for Colorado under 20%

ENERGY METABOLITES AND BIOMOLECULAR BUILDING

BLOCKS.Carbohydrates

LipidsProteins/Amino Acid

VITAMINS AND MINERALSVariety of uses, but NOT an energy source.

Nutritional Components

Simple Sugars Complex Carbohydrates

Carbohydrates

Carbohydrates in Diet

Complex carbohydrates require digestion, slowly enter circulation.

Simple sugars are rapidly absorbed.

Excess blood glucose increases fat storage, increased glycosylation of LDLs. Simple Sugar

Complex Carbohydrate

Dietary Proteins and Amino Acids

Typically require 0.8g/kg/day

Protein toxicity can occur with as little as 2g/kg/day in individuals with pre-existing renal disease.

Animal derived proteins typically have sufficient spectrum of amino acid content.

Grains lack lysine, legumes low in methionine.

Lipids

Diverse category that includes cholesterol, phosphoglycerides, triglycerides, sphingolipids.

Source of fatty acids, omega-3 and omega-6 are essential dietary components.

Dietary Fats and Prostaglandins, Thromboxanes, and Leukotrienes.

Dietary intake influences precursors for synthesis of prostaglandins, thromboxanes, and leukotrienes.

Hormonal Role in Hunger

Cholecystokinin

Short-term satiety signal released from I-cells.

Leptin

Satiety signal released from adipose tissue.

Ghrelin

First identified circulating hunger-inducing hormone. Released from fundus and pancreatic epsilon cells.

NPY neuron

GI L

NPY

What Diet Is Best?

Weight Watchers

Zone

Atkins

Jenny CraigFlexitarian

LEARNVolumetrics

Mediterranean diet

Anti-Inflammatory diet

TLC diet

Engine 2 Diet

Biggest Loser diet

Eco-Atkins

Flat Belly diet

Spark Solution diet South Beach

diet

Macrobiotic

Raw Food diet

Slimfast

Acid Alkaline diet

Nutrisystem

New Glucose Revolution

Paleo Dukan

DASH

Mayo Clinic dietOrnish

Vegetarian

Vegan

The Debate

What type of diet is most effective for losing weight? Those that emphasize protein? Those that emphasize carbohydrates? Those that emphasize fats?

Variable studies: some show benefit with low-CHO, high-protein diets over high-CHO, low-fat diets, but other studies do not show this effect.

Other studies have shown benefit with vegetarian (high CHO, low fat) over conventional high CHO, low fat diet

Low fat vs. moderate fat: mixed reviews

Let’s Look at Some Studies

ARTICLE:

“Comparison of the Atkins, Zone, Ornish, and LEARN Diets for Change in Weight and Related Risk Factors Among Overweight Premenopausal Women: The A to Z Weight Loss Study: A Randomized Trial”

JAMA 2007

Outcomes: Weight loss Lipid profile Body fat Waist-hip ratio Fasting insulin and glucose levels Blood pressure

JAMA. 2007;297(9):969-977.doi:10.1001/

jama.297.9.969.

RESULTS

Atkins: lost more weight and experienced more favorable overall metabolic effects at 12 months.

Weight loss: (at 12 months) Atkins: 4.7kg LEARN 2.6kg Ornish 2.2kg Zone: 1.6kg

Date of download: 4/30/2014Copyright © 2014 American Medical Association.

All rights reserved.

From: Comparison of the Atkins, Zone, Ornish, and LEARN Diets for Change in Weight and Related Risk Factors Among Overweight Premenopausal Women:  The A TO Z Weight Loss Study: A Randomized Trial

JAMA. 2007;297(9):969-977. doi:10.1001/jama.297.9.969

Baseline values were carried forward for any missing values. The overall diet group × time interaction was significant (P<.001). The analysis of variance test for differences among diet groups in weight change from baseline was significant at 2 and 6 months (P<.001), and at 12 months (P = .01). Analyses of all pairwise differences by the Tukey standardized range test (<.05) indicate that the Atkins diet group was significantly different than all other diet groups at 2 and 6 months and that the Atkins diet group was significantly different than the Zone diet group at 12 months. There were no significant differences among the Zone, LEARN, or Ornish diet groups at any time point. Error bars indicate standard error of the mean.

Figure Legend:

Mean Changes in Outcomes at 12 Months

Atkins Zone LEARN Ornish P value

Body mass

-1.65 -.53 -.92 -.12 0.01

Body fat %

-2.9 -1.3 -1.0 -1.5 0.07

Waist/hip ratio

-0.019 -0.013 -o.009 -0.012 .10

LDL-C 0.8 0.0 0.6 -3.8 .49

HDL-C 4.9 2.2 2.8 0 0.002

TG -29.3 -4.2 -14.6 -14.9 .01

Non HDLc

-5.1 -0.5 -4.0 -6.8 .36

Insulin -1.8 -1.5 -1.8 -0.2 .17

Glucose -1.8 -1.2 0.5 -0.8 .54

Systolic BP

-7.6 -3.3 -3.1 -1.9 <.001

Diastolic BP

-4.4 -2.1 -2.2 -0.7 .009

Very Low CHO diet vs. Calorie Restricted Low Fat diet

2003 study on very low CHO diet and calorie restricted low fat diet: (53 patients)

Very low CHO: lost more weight and body fat than the low fat diet.

Over 6 months: no deleterious effects noted for CV risks

Blood pressure, Glucose, lipids, Insulin : same changes in both groups

(J Clin Endocrinol Metab 88:1617–1623, 2003)

2005: Comparison Atkins, Ornish, Weight Watchers, Zone

2005 JAMA: (161#) Weight loss:

Atkins: 2.1kg Zone: 3.2kg Weight Watchers: 3.3kg Ornish 3.3kg

Each diet decreased LDL/HDL ratio by 10%. No effect on BP and glucose

JAMA. 2005;293(1):43-53. doi:10.1001/jama.293.1.43.

2006: Low CHO vs. Low fat on Weight Loss and CV Risks

447 people

At 6 months: Low CHO lost more weight, but at 12 months, there was no difference in weight loss between the 2 groups

No change in BP

Low CHO: TG and HDL improvedLow Fat: total cholesterol and LDL improvedArch Intern Med. 2006;166(3):285-293. doi:10.1001/archinte.166.3.285.

Conclusion:

“Low-carbohydrate, non–energy-restricted diets appear to be at least as effective as low-fat, energy-restricted diets in inducing weight loss for up to 1 year.

However, potential favorable changes in triglyceride and high-density lipoprotein cholesterol values should be weighed against potential unfavorable changes in low-density lipoprotein cholesterol values when low-carbohydrate diets to induce weight loss are considered.”

Arch Intern Med. 2006;166(3):285-293. doi:10.1001/archinte.166.3.285

“Effect of an energy-restricted, high-protein, low-fat diet relative to a conventional high-carbohydrate, low-fat diet on weight loss, body composition, nutritional status, and markers of cardiovascular health in obese women.”

2005 study

Weight loss: both diets: 7.3# in 12 weeks

High protein diet: Decreased TG Decreased body fat

Both diets improved LDL, HDL, glucose, insulin, C-reactive protein

Conclusion: “An energy-restricted, high-protein, low-fat diet provides nutritional and metabolic benefits that are equal to and sometimes greater than those observed with a high-carbohydrate diet.”

Am J Clin Nutr. 2005 Jun;81(6):1298-306

“A Dietary Quality Comparison of Popular Weight-Loss Plans”

Compared: New Glucose Revolution: low glycemic index Weight Watchers: point system based on energy, fat, fiber Atkins: low CHO, high fat diet (4 phases) South Beach: 3 phases (recommends certain CHO and fats) Zone: reduced CHO, low energy diet 40% CHO, 30%protein,

30% fat Ornish: <10% from fat. All animal products are excluded 2005 US Dept of Agriculture Food Guide Pyramid

Dietary quality was measured by the Alternate Healthy Eating Index (AHEI)

Purpose of study: compared dietary quality as well as other nutrients associated with CVD

J Am Diet Assoc. Oct. 2007: 107(10): 1786-1791

Dietary quality is defined as the degree to which a diet reduces risk for CVD disease

Obesity is associated with an increased risk for CV disease

Given that obesity is a risk factor for CVD, a weight loss plan that is optimal will not only facilitate weight loss, but will reduce CVD reduction.

AHEI

Was developed to improve the Health Eating IndexAHEI is twice as strong a predictor of CVD over the

HEINine components:

Fruit Vegetables Nuts and soy Ratio of white to red meat Ceral fiber Trans fat Ratio of polyunsaturated fat to saturated fat Alcohol Duration of multivitamin use

Several nutrients important for CVD risk reduction were also analyzed: CHO Fat Protein Percent energy from saturated and monounsaturated

fat N-3 fatty acids Total fiber Sodium

AHEI Scores

Diet Optimal: 70

Ornish 64.6

Weight Watchers- high CHO

57.4

New Glucose Revolution 57.2

South Beach/Phase 2 50.7

Zone 49.8

2005 Food Guide Pyramid 48.7

Weight Watchers high protein

47.3

Atkins 100g CHO 46

South Beach/Phase 3 45.6

Atkin 45g CHO 42.3

HEI vs. AHEI

HEI: created at first to identify dietary factors associated with reduced CVD risk and to evaluate a plan’s potential to improve lipid levels and obesity.

It did not predict CVD mortality however because it did not distinguish between the different types of CHO and fats

AHEI: found to be twice as good at predicting CVDHow is this helpful? The AHEI may help to establish

long term plans for weight loss and thus affecting CVD risks as well.

Most plans can lose weight in the short term, but it’s the long term effects over time that matters.

OmniHeart Study

Compared 3 diets: Carbohydrate-rich diet, similar to the DASH diet; Diet rich in protein, approximately half from plant

sources; Diet rich in unsaturated fat, predominantly

monounsaturated fat.Goal: all 3 diets are low in saturated fat. The

study looked at blood pressure and serum lipids

OmniHeart Study

Compared with CHO diet: Protein diet:

Decreased systolic BP 1.4mmHg without HTN, and 3.5 with HTN Decreased LDL 3.3mg/dL, Decreased HDL 1.3 md/dL Decreased TG 15.7mg/dL

Unsaturated fat diet: Decreased systolic BP 1.3mmg without HTN, 2.9 with HTN No change in LDL Increased HDL 1.1mg/dL Decreased TG 9.6mg/dL

Conclusion: partial substitution of CHO with either protein or a monounsaturated fat diet can further lower BP, improve lipids and decrease CV risk.

JAMA. 2005;294(19):2455-2464. doi:10.1001/jama.294.19.2455.

Lyon Heart Study

300 subjectsStudy stopped early because of benefits on

heart disease50-70% lower risk of recurrent heart diseaseThis is a secondary prevention trial

Circulation. 2001;103:1823-1825

PREDIMED Study

Primary Prevention of Cardiovascular Disease with a Mediterranean Diet

Studied efficacy of 2 Mediterranean diets: One supplemented with extra virgin olive oil and the

other supplemented with nuts. Compared with low fat diet

Conclusion: the results supported a Mediterranean diet for primary prevention of cardiovascular disease

N Engl J Med 2013; 368:1279-1290April 4, 2013DOI: 10.1056/NEJMoa1200303

Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease

American Journal of Clinical Nutrition: published Jan. 10, 2010: provided a lot of controversy about saturated fat

Meta-analysis of 21 studiesConclusion:

“A meta-analysis of prospective epidemiologic studies showed that there is no significant evidence for concluding that dietary saturated fat is associated with an increased risk of CHD or CVD. More data are needed to elucidate whether CVD risks are likely to be influenced by the specific nutrients used to replace saturated fat.”

DASH Diet

“Comparison of Weight-Loss Diets with Different Compositions of Fat, Protein and Carbohydrates”

811 overweight subjectsAssigned to 4 dietsStudy : 2 yearsPrimary outcome: change in body weight

after 2 years comparing different diets

N Engl J Med 2009: 360: 859-873, Feb. 26, 2009

Diets Studied:

Diet Fat Protein CHO

1: low fat, average protein

20% 15% 65%

2: low fat, high protein

20% 25% 55%

3: high-fat, average protein

40% 15% 45%

4: high fat, high protein

40% 25% 35%

BMI 25-40-30-70 years old-2x2 factorial design: 2 diets low-fat, 2 diets high-fat, and

2 diets were average protein, and 2 were high protein-<8% saturated fat, 20 g fiber/day, 150mg cholesterol per

1000 kcalDiets were randomized, daily meal plans provided-deficit of 750 kcal per day from baselineGroup sessions/individual sessionsPhysical activity goal: 90 minutes moderate exercise per

weekBody weight and waist circumference measures

Primary outcome: change in body weight over 2 year period

Secondary outcome: change in waist circumferenceNote:

Most of the weight loss occurred in first 6 months (6.5kg) After 12 months, all groups on average, slowly regained body

weight 23% continued to lose weight from 6 months to 2 years

At 2 years: 31-37% had lost at least 5% of initial body weight 14-15% had lost at least 10% of their initial weight 2-4% lost 20kg or more

All diets reduced risk factors for CV disease and diabetes at 6 months and 2 years

The 2 low fat diets and highest CHO diet decreased LDL more than the high fat diet or lowest CHO diet

Lowest CHO diet increased HDL more than High CHO diet

All diets decreased TG similarlySerum insulin levels: all diets except high CHOBP decreased 1-2mmHg in all dietsMetabolic syndrome: present in 32% at start and

after 2 years 19-22% overall

HDL: increased in the lowest CHO diet than in highest CHO diet

Attendance at group sessions strongly predicted weight loss at 2 years

Principal finding: Diets were equally successful in promoting weight loss

that was clinically meaningful Adherence to the diets was the most challenging

Conclusion: “Reduced calorie diets result in clinically meaningful

weight loss regardless of which macronutrients they emphasize.”

Mean Change in Body Weight and Waist Circumference from Baseline to 2 Years According to Dietary Macronutrient Content.

Sacks FM et al. N Engl J Med 2009;360:859-873.

So what does this mean?

When looking at the studies, there is not clear evidence that one diet prevails over another for weight loss.

There are strong studies regarding the Mediterranean diet in both primary and secondary prevention in cardiovascular disease.

So what advice do I give to patients?

There are lots of “fad” diets out there. Become familiar with the popular diets and

be ready to discuss them with your patient. The key is finding something that the patient

will adhere to and stay withDIET is a 4 letter word and is not allowed!Rather, “lifestyle changes” is the goal!

US News and World Report: Best Diets

Best Diets OverallBest Weight LossBest Diabetes DietsBest Heart Healthy DietsBest Commercial Diet PlansBest Diets for Healthy EatingEasiest Diets to FollowBest Plant Based Diets

USDA Food Guide Pyramid

The original pyramid did not point the way to healthy eating

In 2005 it was replaced with My Pyramid: the old pyramid turned on it’s side, but it was vague and confusing

June 2011: replaced it with My PlateThe plate still falls short on the nutrition

advice they need to choose healthy diets.

Healthy Eating Pyramid/Healthy Eating Plate

Developed by Harvard School of Public Health, updated in 2008

Developed the Healthy Eating Plate to replace My Plate (2011)

Based on best available scientific evident about links between diet and health

The pyramid has a foundation of daily exercise and weight control.

Simple rule of energy balance: Weight change = calories in – calories out

Problems

Nutrition advice by law must be considered for revision every 5 years

Government seeks a panel of expertsThe panelists are subject to intense lobbying from

National Dairy Council, United Fresh Fruit and Vegetable Association, the Soft Drink Assn, the American Meat Institute, the National Cattlemen’s Beef Assn, the Salt Institute, and the Wheat Foods Council.

The guidelines can determine what food products Americans buy and determine how billions of dollars are spent.

“Can We Say What Diet is Best for Health?”

Drs. Katz and Dr. Meller: Ann Rev Public Health 2014. 34:83-103

There have been no long term studies comparing diets

The weight of evidence supports a theme of healthful eating, with variations among this theme.

Compared: Low CHO, Low fat, Low glycemic, Mediterranean, Mixed balanced, paleolithic, vegan, other

If diet denotes a set of rigid principles, then, no, we can’t say what diet is best.

However, if by diet, we mean a more general dietary pattern, then yes, we can say what diet is best:

Evidence supports: Diets consisting of minimally processed foods Diet of foods mostly direct from nature Diets with exaggerated emphasis on any one nutrient

or food is ill advised Diets need to consist of a complete dietary pattern

New Evidence: March 2014

“Fruit and vegetable consumption and all-cause, cancer and CVD mortality: analysis of Health Survey for England data” J Epidemiol Community Health doi: 10.1136/jech-

2013-203500 An inverse association exists between fruit and

vegetable consumption and mortality Benefits seen in up to 7+ portions daily

Fruit and vegetable consumption: associated with reduced cancer and CV mortality

Vegetables may have a stronger association with mortality than fruit

Fresh vegetables were most protective, while frozen/canned fruit showed increased mortality

Eating 7 or more portions of fruit and vegetables can reduce the risk of death by 42%

Bottom Line

Eat more vegetables and fruitEat less processed foodsEat whole grainsEat white meat over red meat, eat fish at

leasttwice weeklyEat healthy oils and fatIncrease intake of nuts, seeds, beansDairy 1-2 servings a dayExercise more

THANK YOU!

Questions?