Deconstructing Diets
Melita Schuster, DO
Mike LaFontaine, PhD
Marian University
College of Osteopathic Medicine
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%
Nutritional Components
ENERGY METABOLITES AND
BIOMOLECULAR BUILDING
BLOCKS.
Carbohydrates
Lipids
Proteins/Amino Acid
VITAMINS AND MINERALS
Variety of uses, but NOT an energy source.
Carbohydrates
Simple Sugars
Complex 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.
I
L
Leptin
NPY neuron
Satiety signal released
from adipose tissue.
Ghrelin
First identified circulating
hunger-inducing hormone.
Released from fundus and
pancreatic epsilon cells.
G
NPY
What Diet Is Best?
Eco-Atkins
Macrobiotic
Ornish
DASH
Mayo Clinic diet
TLC diet
Mediterranean diet
Raw Food diet
Weight Watchers
Spark Solution diet
Vegetarian
Anti-Inflammatory diet
Vegan
Flat Belly diet
Jenny Craig
Paleo
Engine 2 Diet
Nutrisystem
Zone
Atkins
New Glucose Revolution
LEARN
Biggest Loser diet
Acid Alkaline diet
Volumetrics
Flexitarian
Slimfast
Dukan
South Beach diet
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”
 Outcomes:
 Weight loss
 Lipid profile
 Body fat
 Waist-hip ratio
 Fasting insulin and glucose levels
 Blood pressure
JAMA 2007
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)

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Atkins: 4.7kg
LEARN 2.6kg
Ornish 2.2kg
Zone: 1.6kg
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
Figure Legend:
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 atCopyright
12 months.
There
were no
significant differences among the Zone, LEARN, or
© 2014
American
Medical
Date
of download:
Ornish
diet groups4/30/2014
at any time point. Error bars indicate
standard
error
of
the
mean.
Association. All rights reserved.
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 improved
 Low Fat: total cholesterol and LDL improved
Arch 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, energyrestricted 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
 Weight loss: both diets: 7.3# in 12 weeks
“Effect of an energyrestricted, highprotein, low-fat diet
relative to a
conventional highcarbohydrate, lowfat diet on weight
loss, body
composition,
nutritional status,
and markers of
cardiovascular
health in obese
women.”
 High protein diet:
Decreased TG
 Decreased body fat
 Both diets improved LDL, HDL, glucose,
insulin, C-reactive protein

 Conclusion: “An energy-restricted, high-protein, lowfat diet provides nutritional and metabolic benefits that
are equal to and sometimes greater than those observed
with a high-carbohydrate diet.”
2005 study
Am J Clin Nutr. 2005 Jun;81(6):1298-306
“A Dietary Quality Comparison of Popular
Weight-Loss Plans”
 Compared:
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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 Index
 AHEI is twice as strong a predictor of CVD over the HEI
 Nine components:
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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:
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


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 CVD
How 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 subjects
 Study stopped early because of benefits on heart
disease
 50-70% lower risk of recurrent heart disease
 This 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 studies
 Conclusion:

“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 subjects
 Assigned to 4 diets
 Study : 2 years
 Primary 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 kcal
Diets were randomized, daily meal plans provided
-deficit of 750 kcal per day from baseline
Group sessions/individual sessions
Physical activity goal: 90 minutes moderate exercise per
week
Body weight and waist circumference measures
 Primary outcome: change in body weight over 2 year
period
 Secondary outcome: change in waist circumference
 Note:



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 similarly
Serum insulin levels: all diets except high CHO
BP decreased 1-2mmHg in all diets
Metabolic 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 with
 DIET is a 4 letter word and is not allowed!
 Rather, “lifestyle changes” is the goal!
US News and World Report: Best Diets
 Best Diets Overall
 Best Weight Loss
 Best Diabetes Diets
 Best Heart Healthy Diets
 Best Commercial Diet Plans
 Best Diets for Healthy Eating
 Easiest Diets to Follow
 Best 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 Plate
 The 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 experts
 The 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-2013203500
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 fruit
 Eat less processed foods
 Eat whole grains
 Eat white meat over red meat, eat fish at leasttwice




weekly
Eat healthy oils and fat
Increase intake of nuts, seeds, beans
Dairy 1-2 servings a day
Exercise more
Questions?
THANK YOU!