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Food matters: why we are getting fatter and what can we do about it? Simon Thornley Public Health Physician & Lecturer University of Auckland

Food Matters

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Talk given at St George's Anglican Church, 7/05/2011. The link to the video is: http://www.youtube.com/watch?v=8hcAjyOFX1M

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Page 1: Food Matters

Food matters: why we are getting fatter and what can we do about

it? Simon Thornley

Public Health Physician & Lecturer

University of Auckland

Page 2: Food Matters

Summary

What is science?

Is there an obesity epidemic?

A brief history of nutrition

I get involved…

Food addiction

What next?

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Dairy photo

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Museum photo…

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What is science?

“In God we trust, all others bring data”

“First establish the facts, then seek to

explain them” Aristotle

Anarchistic

Consensus not useful

Hypothesis and argument

Disproof useful, not proof.

Probabilities over absolutes

Page 6: Food Matters

The obesity epidemic

Where has it occurred?

Over what time period?

Explanations?

What have we been told to eat?

Is it working?

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Is there an obesity epidemic?

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What happened in the 1960s?

Diet-Heart Hypothesis

Heart disease caused by saturated fat

Response: reduce fat (↑sugar or carb.)

Cheap sugar (HFCS)

American Heart Assoc.– spread to other

English speaking countries Taubes G. The Diet Delusion. New York: Vermilion; 2007.

Page 9: Food Matters

Laws of thermodynamics

A – B = C

A = Energy in (food)

B = Energy out (burned, exercise/basal

metabolic rate)

C = Energy stored (as fat)

δA - environmental change (Coke ads/vending

machines)

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MY STORY

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My thoughts on obesity

Medical training

Traditional

Nutritional theory

- Energy density

Public Health

Understanding

addiction

Research

Similarities

between

obesity and

smoking

Research

Critique of

energy density

Focus on sugar

1994 2005 2007 2011

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Tobacco withdrawal

Page 13: Food Matters

In detail

Signs and

symptoms

Duration

(weeks)

Proportion

(%)

Irritability < 4 50

Depression < 4 60

Restlessness < 4 60

Poor concentration <2 60

Increased appetite >10 70

Sleep disturbance <1 25

Urges to smoke >2 70

Mouth ulcers <4 40

Constipation >4 17

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Addiction? Automatic behaviour

Rational behaviour

e.g. Planning,

Picking up children

after work

Addiction –

Automatic,

withdrawal, can‘t

stop, causes harm

e.g. heroine

Automatic

behaviour?

e.g. breathing

Cortex Mid brain/brain

stem

Page 15: Food Matters

Negative re-inforcement

Withdrawal

discomfort

Puff

cigarette

Withdrawal

relief More

puffs

Nicotine

metabolised

Page 16: Food Matters

How to profit from tobacco...?

Nicotine delivery

Royal College of Physicians, Nicotine in Britain, 2000

Page 17: Food Matters

FOOD ADDICTION?

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Carbohydrate?

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Eating and addiction?

―Atkins Diet‖

An executive who had tried obesity surgery, laxatives, diets, everything…

“Often I would shake until I could put some sugar in my mouth”

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“I had an hour’s drive from my office to

my home, and I knew every

restaurant, every candy machine and

every soft drink dispenser along the

whole route.”

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What about glucose?

Glycemic index very similar for glucose

Is carbohydrate the same as nicotine?

Is low GI a way out like nicotine patch or

gum?

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Bread - White vs Vogel’s

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Glucose: glycemic index?

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What about sugar?

Sugar is actually moderate GI

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WHAT DO WE KNOW ABOUT SUGAR?

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BIG SUGAR Brian Mckenna

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What does the good book say?

“It is not yet clear whether any single

attribute of the Western way of life is

particularly important in increasing the risk

of diabetes. Excess sucrose has largely

been exonerated as an important dietary

factor in the aetiology of type 2 diabetes...”

J. I. Mann and A. S. Truswell Diseases of overnourished societies and the need for dietary change: in the Oxford

Textbook of Medicine, 4th Edition.

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Sugar – traditional views

30% increase over last 30 years Popkin BM, Nielsen SJ. The sweetening of the world's diet. Obesity Research 2003;11(11):1325-32.

―empty calorie‖ Nestle M. Soft drink "pouring rights": marketing empty calories to children. Public Health Reports

2000;115(4):308-19.

Sucrose and other free sugars restricted to

up to <15% of total caloric intake, due to

excess energy and dental caries. Food and nutrition guidelines (Ministry of Health) 2003.

Fructose not mentioned

Page 31: Food Matters

Average NZ consumption:

UN statistics (‗07)– 153g/day

= 38 teaspoons/ day

17% of total energy

Compare – 1961 – 33 teaspoons/day

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Average daily dose

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Absorption

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Recent guidelines

American Heart Association 2002 Circulation 2002;106;523-527

“No definitive evidence... Rely on

professional judgement”

“Consuming fructose either free or in the

form of sucrose has neither beneficial or

adverse effects”

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BIG SUGAR Brian Mckenna

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Update...

“Originally proposed as the ideal sweetener

for people with diabetes... Fructose... has

been indirectly implicated in the epidemics

of obesity and type 2 diabetes” Circulation 2009;120;1011-1020

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Update

Upper limit set to reduce heart disease risk

and maintain healthy weight

“6 teaspoons per day” for women

“9 teaspoons per day” for men

Page 39: Food Matters

Health effects?

1990s ADA encouraged diabetics to eat

sugar/HFCS

2000s about face due to ↑triglycerides

Small RCTs:

Rots teeth; raises triglycerides, ↓HDL, ↑BP,

↑urate. Johnson, R.J., et al., Hypothesis: Could Excessive Fructose Intake and Uric Acid Cause Type 2 Diabetes? Endocr

Rev, 2009. 30(1): p. 96-116.

Segal, M.S., E. Gollub, and R.J. Johnson, Is the fructose index more relevant with regards to cardiovascular disease

than the glycemic index? European Journal of Nutrition, 2007. 46(7): p. 406-17.

Page 40: Food Matters

Sugar - What has changed?

GI ignores fructose –Sugar half fructose (half

glucose)

4x as sweet as glucose

Links to gout, diabetes

Human studies limited,

Does not trigger satiety hormones→↑hunger E.g. Insulin, CCK

Johnson, R.J., et al., Hypothesis: Could Excessive Fructose Intake and Uric Acid Cause Type 2 Diabetes? Endocr Rev, 2009. 30(1): p. 96-

116.

Segal, M.S., E. Gollub, and R.J. Johnson, Is the fructose index more relevant with regards to cardiovascular disease than the glycemic index?

European Journal of Nutrition, 2007. 46(7): p. 406-17.

Page 41: Food Matters

Refined carbohydrate (high GI)

Reduced risk of chronic disease

Heart disease, cancer, gallstones. Barclay A, Petocz P, McMillan-Price J, Flood V, Prvan T, Mitchell P, et al. Glycemic

index, glycemic load, and chronic disease risk—a metaanalysis of observational

studies. Am J Clin Nutr 2008;87:627-37

Modest weight loss Thomas D, Elliott E, Baur L. Low glycaemic index or low glycaemic load diets for

overweight and obesity. Cochrane Database of Systematic Reviews 2007;Art. No.:

CD005105. DOI: 10.1002/14651858.CD005105.pub2(3).

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What about saturated fat?

Meta-analyses now show no link between

eating saturated fat and heart disease.

Skeaff CM, Miller J. Dietary Fat and Coronary Heart Disease: Summary of Evidence

from Prospective Cohort and Randomised Controlled Trials. Ann Nutr Metab

2009;55:173–201

Mente A, de Koning L, Shannon HS, Anand SS (April 2009). A systematic review of the

evidence supporting a causal link between dietary factors and coronary heart

disease. Arch. Intern. Med. 169 (7): 659–69.

Page 43: Food Matters

Sugar and CHD?

Dental caries Coronary Heart

Disease

Sugar

consumption

Page 44: Food Matters

Sugar addiction?

Yes in rats

Anecdote in humans

Page 45: Food Matters

Food addiction-evidence

Neural pathways (dopamine)

Correlation between obesity & receptor density like other addictions

Automaticity – serving size, availability

Rise in sugar consumption worldwide over last 40 years.

Rodents – sugar induces withdrawal; fat does not.

Page 46: Food Matters

Dairy photo

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Food addiction in the headlines…

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After the publicity... my inbox...

“For the first three weeks I cut all

processed sugar and flour from my diet

and suffered mood swings with extreme

tension and depression, even a sense of

hopelessness at times, I had horrible

stomach pains, all my joints and muscles

throbbed, and I had the shakes

constantly.”

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“I don't even know how to describe the

horrible headaches that went along with

all this. People who knew me started

thinking I was hiding a drug problem.”

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“The worst physical symptoms have been

gone for about two weeks now, and the

cravings are finally starting to subside… I

look at birthday cake today and all I see is

myself curled up in the foetal position

crying in bed. “

Page 51: Food Matters

Overeater’s Anonymous

“When you are addicted to drugs you put

the tiger in the cage to recover; when you

are addicted to food, you put the tiger in the

cage, but take it out three times for a walk”

Kerri-Lynn Murphy Kriz

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Critique: Academia

“Any addictive type of hypothesis can't

explain the rise that we've seen over the

last 20 to 30 years of obesity. It's not that

the whole population becoming more of

an addictive personality type or whatever.

I think there are other factors to explain

obesity at a population level.”

Prof. Boyd Swinburn, Professor of Population Health,

Deakin University 13 Jan 2009

Page 53: Food Matters

Citique: Academia and Industry

“We write in response to Thornley et al’s

viewpoint article “The New Zealand sugar

(fructose) fountain...” The data quoted on

sugar consumption in New Zealand are

presented misleadingly and are not

correctly referenced to primary sources.” Parnell and colleagues NZMJ 2010

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“Sugar Research Advisory Service”

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BIG SUGAR

Brian McKenna

http://www.youtube.com/watch?v=8hcAjyOFX1M

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SO WHAT?

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Conclusions

Nutrition ignores motivation to eat, instead

focuses on energy

Low energy or low fat approach has been

unhelpful for populations

Sugar intake continues to rise

Likely subtle addiction to refined carb and

sugar

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Conclusions

↓ sugar likely to ↓

Heart disease

Obesity

Diabetes

Dental caries

Other diseases?

No downsides except $$$

Page 60: Food Matters

What about children?

Big sugar

Page 61: Food Matters

My advice…

Zero sugar (alternatives)

Whole grains over white flour (low GI)

No low fat food – tends to be high in

sugar or refined carbohydrate

Page 62: Food Matters

Other lessons

Ink is a powerful weapon

The ideals of science are only that

‗Authorities‘ hold power over junior

scientists (jobs, grants)

Going alone takes courage

History over latest and greatest

Page 63: Food Matters

The book

―Sickly sweet: sugar, refined carbohydrate,

addiction and global obesity‖

Nova

To be released in about three months.

Page 64: Food Matters

Publications

Thornley S et al. The New Zealand sugar (fructose) fountain: time

to turn the tide? NZMJ 2010.

Thornley S et al. Carbohydrate withdrawal: is recognition the first

step to recovery? NZMJ 2010

Thornley S et al. Per capita sugar consumption is associated with

childhood asthma prevalence. Primary Care Respiratory Journal.

2011.

Thornley S et al. The obesity epidemic: is glycemic index the key to

unlocking a hidden addiction? Medical Hypotheses. 2008

Page 65: Food Matters

Other reading

Freedman ―Wrong: Why experts keep

failing us and how to know when not to

trust them‖. Little, Brown and Company,

2010. (journalist)

Taubes G. The Diet Delusion. New York:

Vermilion; 2007. (physicist/writer)

Gillespie D. Sweet poison. Sydney:

Penguin; 2008 (lawyer)

Page 66: Food Matters

Thank you!