Transcript Slide 1

Another review:
http://kitses.com/animation/swfs/digestion.swf
Dr. Montville
Fall 2010
AMA – Nutrition is, “The science of food, the
nutrients and substances therein, their
interaction, action, and balance in relation to
health and disease….” and the digestive
and metabolic processes therein.
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1 calorie = Amount of energy
required to raise temp of 1g of water
by 1C
Relating to food and nuts, 1,000 cal
= 1 Kilo calorie = 1 Calorie
Energy needs:
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Basal metabolism = f(lean body mass)
60 – 70 % of basal requirement is from
muscle.
25-40% from physical activity
10% “keeping warm”
 Calories count
– Intake > used: Gain weight
– Intake < used: Lose weight
– Intake = used: Maintain weight
Easier to keep weight off than lose it
 Body has “set point”
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Controlled by:
 Exercise
 Intake
control
 Behavior modification
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Calories and exercise- Dr. Montville’s cycling
odyssey
Moving 175 lbs at 16.2 mph requires 700
calories per hour
M.S. ride: 80 miles at 16.2 mph = 5 hours
Caloric expenditure = 3,500 calories
Weight: Gain or lose?
cycling 2004
m iles
3200
3000
2800
2600
2400
2200
2000
1800
1600
1400
1200
1000
800
600
400
200
0
day of year
4
cumulative mile
19
37
73
89
119 133 143 157 169 183 206 230 250
230
weight
220
% body fat x 10
Log. (% body fat x
10)
210
Linear (weight)
200
190
180
4
19
37
73
89
119 133 143 157 169 183 206 230 250
 Ways
to monitor “appropriate weight”:
Height and weight tables
– Body mass index (BMI)
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 BMI
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= Weight (kgs) % (height in meters)2
“Should” be 18-25
> 30 = obese;
 Over-estimates
(athletes)
risk in muscular people
“I’m not overweight, I’m under height.”
Under height:
 Heart disease, diabetes,
stroke
 Shorter life span
 ~10% dip in earning
 Less likely to finish
college
 Smaller lungs, narrower
vessels
 U.S. losing height
President Barack Obama
6 foot, two inches
 175 pounds
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 BMI
= ~23
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Remember? Eating serves
*many* social, cultural, and
physiological roles
 Endorphins
 Serotonin
Eating Disorders
 Anorexia Nervosa
 Bulimia
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Extreme weight loss
<85% of ideal body
weight
Distorted body image
Societal pressure
Control needs
90% women, 10% male
Amenorrhea
Can be Fatal
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Lower body temperature
Lanuga (downy hair on skin)
Rough dry skin
Low blood pressure
Low white blood cell count
Depression
Tooth loss
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Binge and purge 2x/week for 2-3 months
Single binge up to 12,000 calories
Lack of control and inappropriate compensation
40% male, 60% female, 5-17% of college age
females
They recognize behavior as:
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Abnormal
Secretive
½ have major depression
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Slightly above normal body weight
Tooth demineralization
Esophageal damage
Low potassium, arrhythmia
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Disordered Eating
No Menstruation
Osteoporosis
“Nutritionism” defined The tenants of
nutritionism:
Well, he actually doesn’t define
“nutritionism” but basically:
-The key to understanding food
is in the individual nutrients and
chemicals (that we recognize). Corollary – Foods are not a
system.
-The whole food isn’t important.
-Manufactured = natural based
on defined nutrients.
-It’s an ideology.
-Nutrition defines it, Food
Science manufactures it.
- It’s good for business.
In Defense of Food
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It’s not food, and it’s not eating.
Who do we have to defend ourselves from?
Nutrition Science and Food Science
“The Nutritional Industrial Complex”
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It’s not about the food, it’s about the nutrition.
We need experts to tell us what to eat.
“Health” is narrowly defined.
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Ominvores can eat just about anything.
Eat food, or thousands of “food like”
substances?
Food marketing = $32 billion
“Lipid hypothesis” unsupported. (Carbs and
proteins too)
“Salt hypothesis” unsupported.
If the “French Paradox” really so
paradoxical?
Foods are very complex
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Studied using scientific reductionism.
Food consumption is relatively inelastic; if
you are eating more of one thing, you are
eating less of something else.
Pollan Claims
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25% suffer from metabolic syndrome
2/3 over weight
Diet related disease are killing the majority of
us.
Aborigines experiment – take them back to
the bush.
Acknowledges (just once) that the only way
to reduce disease is to return to the diet and
lifestyle of our ancestors.
Margarine as a
Vehicle for Nutrients
Food Industry
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The whole food system is organized to
produce lots of calories cheaply.
From complex to simple
From quality to quantity
“Fast, cheap, and easy.”
My defense of the food industry
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Has preserved the nutritional quality of “real
foods” by canning, freezing, refrigeration, etc.
Has made “real foods” more readily available
geographically and seasonally.
Has lowered cost. Should foods really be
more expensive? Isn’t that already a matter
of personal choice?
Pollon is reductionist
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Nutrionism is responsible for all our faults. If
we ate better, we’d live longer happier lives.
Pollan’s advice
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Just eat food.
Don’t eat anything that will never spoil.
Don’t eat anything that your great grandmother
would not recognize as food.
Avoid ingredients that you don’t recognize
and/or can’t pronounce.
Avoid High Fructose Corn Syrup.
Avoid foods that make health claims.
Don’t get your calories from the same place your
car does.
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Eat a variety of foods – best source of nutrients is
their natural source.
Eat a balanced diet – don’t over-consume any one
product Single food diets hard to maintain long term.
Eat in moderation – beware of “super-sizing” and
“special occasion” eating.
Be aware of nutrient density – ideally % daily
calories should about equal daily nutritional needs.
Beware of energy (calorie) density – nuts have
more calories per unit weight than fruits do. Fried
foods have more calories than the same food baked
or broiled.
INCREASE ACTIVITY!!!! Building muscle mass
increases basal rate of caloric burn.
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Nutrition is more than weight control (from last lecture)
Weight Control
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% Body fat
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case study, Dr. Montville weight
“Diets”
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Calories count
Methods of monitoring “weight”
A diet that works
Akins and Pritkins
Eating Disorders
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Anorexia nervosa
Bulimia