Mexico: Highest Obesity in World - PowerPoint Presentation

Slide1

Mexico: Highest Obesity in WorldSlide2

What should be done?

Public Health Officials:

Reduce soda consumption

Food & Beverage Producer’s Lobby:

“Obesity comes from taking in more calories than you spend,” said Jaime

Zabludovsky

, chair of the board of

ConMexico

, the processed food and beverage producers’ group. “If Michael Phelps eats 5,000 calories a day and swims 10km, there is no problem. If you eat 2,000 calories per day but don’t move, you have a problem. The source can be soda, tortillas, chocolate, sandwiches, bagels- there is not any product that in itself causes obesity”Slide3

“The idea of balancing calories in with calories out is now the mantra of the soda industry worldwide. An active lifestyle is the solution – not dietary change, and certainly not soda taxes.”Slide4

Conventional Wisdom: it’s all about the calories

Eating just

150 calories more a day than you burn can lead to an extra 5 pounds over 6 months. That’s a gain of 10 pounds a year. If you don't want this weight gain to happen, or you want to lose the extra weight, you can either reduce your ENERGY IN or increase your ENERGY OUT. Doing both is the best way to achieve and maintain a healthy body weight.Slide5

Calories in/calories out?

Energy Balance Model

WHO: “

The fundamental cause of obesity and overweight is an energy imbalance between calories consumed on one hand, and calories expended on the other hand

”Slide6

Conventional Wisdom Explanations for Obesity

We eat too much- too many calories

We exercise too little

We don’t pay attention to what we eat

We live in a “toxic food environment”- fast food, etc.Slide7

Usual Recommendations For Losing Weight

Eat fewer calories

Exercise more

Avoid fatSlide8

Gary Taubes: The Man who shows conventional wisdom is wrongSlide9

Yet, no evidence this works

1960: 1/9 Americans obese

2010: 1/3 Americans obese

2/3 Overweight

Childhood obesity skyrocketingSlide10

Is the person to blame, or the advice?

“We have been told that we must not take in more calories than we burn, that we cannot lose weight if we don’t exercise consistently. That few of us are able to actually follow this advice is either our fault or the fault of the advice

”Slide11

Common Explanations: Blame the person

People Don’t follow advice and eat too much

People Don’t Follow advice and exercise too little

Lack of discipline

Failure of willpowerSlide12

What actually happens when people try to diet?Slide13

Why diets don’t work

It’s not just about caloriesSlide14

Proietto study (NEJM; 2011):

Long-Term Persistence of Hormonal Adaptations to Weight Loss

Recruited 50 obese subjects (M: 233lbs; F: 200 lbs)

Optifast

and 2 cups low-starch diet (500 cal/day)

Lost an average of 30 lbs in 10 weeksSlide15

Maintenance Phase

Individual Nutritionist Support

Promoted exercise and eating less fat, more vegetables

But, slowly began putting on weight

Reported feeling far more hungry and obsessed with foodSlide16

Hormonal Alterations after Starvation

Body acts as though it is starving, tries to regain lost weight

Hormones Measured:

Ghrelin

:

hormone released when hungry

Leptin

:

hormone that suppresses hunger & increases metabolism

Peptide YY:

hormone that suppresses hungerSlide17

Results

Ghrelin

-

higher than at beginning of study

hormone released when hungry

Result:

Hungrier after diet

Leptin

:

lower than at beginning

hormone that suppresses hunger & increases metabolism

Result:

hungrier; lower metabolism

Peptide YY:

lower than at beginning of study

hormone that suppresses hunger

Result:

hungrierSlide18

Implications

Just eating less and exercising more is NOT enough

Body fights against weight loss after dieting stops

Can eat same number of calories after diet, and still gain weightSlide19

Keys Starvation Study

During WW II, conscientious objectors

12 week control phase: establish baseline

24 week starvation phase: goal of decreasing weight by 25%

Cut 1560 calories/day

Potatoes, macaroni, rutabagas

Recovery PhaseSlide20

Results

Calorie restrictions had to be adjusted for each subject to obtain 25% weight loss

Most found it hard to lose weight

Some had trouble losing 10 lbs

Dramatic changes in mood, attitudes towards foodSlide21

all they thought about was food.

would go to restaurants just so they could smell the food.

They lost all desire for anything that didn’t involve food

desire for sex was nonexistent. Slide22

Vermont Prison Overeating Studies

Fed 7,000 calories daily for 6 months

3500 extra/day = 1 lb weight gain

Should have gained 170 lbs over 6 months

Actually gained:Slide23

Argues against calorie hypothesis

The deficit, in Keys’ study, started off at 1,640 calories a day.

Assuming that the deficit remained at 1,640 for the 24 week ‘starvation’ period, if the 3,500 formula were correct, during the 24 weeks, every man should have lost at least 78 pounds in fat alone and more on top of this in water and lean tissue. The average weight loss of the men was less than half of this – 37 pounds – 1.5 pounds per weekSlide24

Results

Vermont Prison Overeating Studies:

Fed 7,000 calories daily for 6 months

3500 extra/day = 1 lb weight gain

Should have gained 170 lbs over 6 months

Actually gained: 40 lbs

Argues against simple calorie explanationSlide25

Calories vs

Diet Composition

3 types of diets, all 1000 calories/day

High

carb

, low fat

Atkins style, high fat

Mediteranean

style

High

carb

diet can actually lead to weight gainSlide26

Bouchard & Tremblay Twin Studies

Genetic Factors in Weight Control Slide27

Overfeeding Stage

12 pairs of identical twins

2 week baseline

Overfed by 1000 calories/day, 6 days/week for 84 days ( total 84,000 extra calories)

24 hour supervision in dorm; limited to 30 min daily walk for exercise

Recorded body fat composition, weight gainedSlide28

Results

Weight gain similar between brothers, but varied considerably between pairs

10 -24 pounds

Pattern of fat distribution also similar between brothers, but varied between pairs

Some gained 3 times as much around abdomenSlide29

Specific Genes?

Speliotes

, et. Al ( 2010) : identified 32 possible genetic variations associated with obesity

Frayling

, et al (2007: FTO gene variant (

Fat mass and obesity-associated protein)

associated with:

Higher insulin levels, glucose, and triglycerides

Lower HDL cholesterol

30% risk of obesity with one copy; 60% with twoSlide30

FTO Gene EffectsSlide31

Is FTO the “Fat Gene”?

Palmer ( 2009) study

Children with this gene consume more calories, after pre-loading

Insulin-resistant

Seem to lack satiety signal

No impact on energy expenditure

Correlation: gene linked with overeating

Does gene

cause

overeating or is overeating the result of other factors?

Can’t tell from this studySlide32

Losing Weight is HardSlide33

People Can Do ItSlide34

But, Keeping Weight Off is Harder

“It’s one of the hardest things there is,” she says. “It’s something that has to be focused on every minute. I’m not always thinking about food, but I am always aware of food.”

Janice Bridge, maintained 135 lb loss for 5 yearsSlide35

Behavior in those who keep it off

National Weight Control Registry

Tracks 10,000 people who have lost at least 30 lbs

Consistent Behavior:

Exercise at least 60 min daily

Daily weigh-ins

Rigid food intake

Eat less ( ~300 fewer calories)Slide36

Dieting Changes Brain Activity

After Weight loss

Bigger response in brain activity in reward centers

Lower response in areas associated with controlSlide37

Perfect Storm

Metabolic changes: body burns fewer calories

Brain Changes: food is more appealing; restraint is lower

Changes can last for up to 6 years post weight-lossSlide38

All Calories not the same(

NYTimes

, 4/15/2012)Slide39

K-E Diet (Ketogenic

Enteric Diet)

Nasogastric

Tube

Provides Protein, Fat, No

Carbs

800 calories a day

Rapid Weight Loss

Induces ketosis: body burns fat

Report little or no hungerSlide40

Are All Calories Actually Equal??Slide41

Conventional Wisdom:” A calorie is a calorie”

Energy Balance Mode:

Calories in/calories out

WHO: “

The fundamental cause of obesity and overweight is an energy imbalance between calories consumed on one hand, and calories expended on the other hand

”Slide42
Slide43
Slide44
Slide45
Slide46

Big Food Angle To Calorie ArgumentSlide47

Coca-Cola Coming Together Campaign

"...beating obesity will take action by all of us, based on one simple, common-sense fact: All calories count, no matter where they come from. ...And if you eat and drink more calories than you burn off, you'll gain weight.”Slide48

Promotes idea that all calories are equalSlide49

Evidence Against “ Calorie is a Calorie”Slide50

All foods are not equalSlide51

Differences Within Given Food

Fruits & Vegetables: if more cell walls broken down, we get more net calories; if walls remain intact, we get fewer

Cooked carrots > raw carrots

Orange Juice > whole orangeSlide52

Diet-Induced Thermogensis

Some foods require us to do more work ( expend heat-energy) to digest

Peanuts, pistachios, almonds

170 calories/label vs. 128 usable

Proteins: require 10-20 times as much heat-energy to digest as fats.

Well-done meat > raw/rare meatSlide53

Carmody, et al., 2011Slide54

Methods

Monitored the weight of mice fed different diets. :

Measured how much the mice moved and how much weight they gained as an indication of the amount of energy that was not being lost through inefficiency as feces.

All things equal, the bigger the mice got on a given diet, the more calories they were getting.

Slide55

Fed adult, male mice organic sweet potatoes (to, in essence, retest what was already known) or organic, lean beef.

served up raw and whole, raw and pounded, cooked and whole, or cooked and pounded.

Standard system of calories, the one used to put the numbers on the food you buy in the store, assumes (and hence also predicts) these have no effect on calorie content; but would they? Slide56

Results

Didn’t differ in level of activity

Did differ in how much they weighed at end of studySlide57

Changes in body mass on tuber diets.

Carmody

R N et al. PNAS 2011;108:19199-19203

©2011 by National Academy of SciencesSlide58

Food preferences on tuber diets.

Carmody

R N et al. PNAS 2011;108:19199-19203

©2011 by National Academy of SciencesSlide59

Changes in body mass on meat diets.

Carmody

R N et al. PNAS 2011;108:19199-19203

©2011 by National Academy of SciencesSlide60

Food preferences on meat diets.

Carmody

R N et al. PNAS 2011;108:19199-19203

©2011 by National Academy of SciencesSlide61

Conclusions

The more foods are processed, the more calories they actually give us

Lost 4

g

on raw Sweet potatoes; gained with cooked

Lost 2

g

on raw meat; lost only 1 on cooked

Mice prefer cooked to rawSlide62

What about Industrial Processing?Slide63

Sadie, et al, 2010Slide64

Methods

People given identical calorie portions of bread & cheese; cross-over design

The meals were either ‘whole’: multi-grain bread & Cheddar cheese (

Sargento

Deli-Slice)

or ‘processed’ cheese sandwiches: white bread & processed cheese (Kraft singles) Slide65

Measured:

energy expended to digest it for 5-6 hrs post meal (post-

prandial

energy expenditure)

Satiety ( how full they felt)Slide66

Comparison of two mealsSlide67

ResultsSlide68

Conclusion: What you eat, not how many calories

-Processed food meal has

requires less energy to digest

-Reduction in energy

“

has

potential implications for diets comprised heavily of

PFs

and their associations with obesity.

”

-

Slightly

larger effect for

females

-No

Difference in satietySlide69

Food Composition of Diet MattersSlide70

Ludwig,et

al JAMA (2012):Effects of dietary composition on energy expenditure during weight-loss maintenance

.

Clinical trial comparing weight loss diets

Put obese subjects on diet to lose 10-15% of body weight

Now susceptible to gaining weight back

Decreased energy expenditure- burn fewer calories than people who naturally weigh the sameSlide71

Diet 1:

low-fat; high in carbohydrates

diet we’re all advised to eat: whole grains, fruits, vegetables, lean sources of protein.

Diet 2:

low

glycemic

index: fewer carbohydrates in total

from beans, non-starchy vegetables and other minimally processed sources

Diet 3:

Atkins: low

carbs

, high fat & proteinSlide72

Results

the fewer carbohydrates consumed, the more energy weight-reduced people expended.

Atkins diet: there was virtually no metabolic adaptation to the weight loss.

subjects expended, on average, only 100 fewer calories a day than they did at their full weights. Eight of the 21 subjects expended

more than they did at their full weights — the opposite of the predicted metabolic compensation.Slide73

On the very low-carbohydrate diet, Dr. Ludwig’s subjects expended 300 more calories a day than they did on the low-fat diet and 150 calories more than on the low-

glycemic

-index dietSlide74

Implications

If subjects were eating low-fat diets, they’d have to add an hour of moderate-intensity physical activity each day to expend as much energy as they would effortlessly on the very-low-

carb

diet. And this while consuming the same amount of calories.

SAME CALORIES, DIFFERENT EFFECTS Slide75

Conclusion

nutrient composition

of the diet can trigger the predisposition to get fat, independent of the calories consumed.Slide76

Ludwig concludes

: “the low-fat diet that has been the primary approach for more than a generation is actually the worst for most outcomes, with the worst effects on insulin resistance, triglycerides and HDL, or good cholesterol.” Slide77

People are different

Even if two people were to somehow eat the same sweet potato cooked the same way they would not get the same number of calories. Slide78

Carmody

et al:

studied a single strain of heavily inbred lab mice such that their mice were as similar to each other as possible.

Yet

the mice still varied in terms of how much they grew or shrank on a given diet, thanks presumably to subtle differences in their behavior or bodies.

Bouchard & Tremblay:

individual variability in weight gain on identical dietsSlide79

Each of us gets different number of calories from same food

People vary because of who we are and who ancestors are:

-amylase ( breaks down starch) & lactose ( breaks down sugar in milk) levels differ across ethnic groups

-lactose-intolerant: get fewer calories from milk products if consumed

-Russians have intestines 5 feet longer than Italians ( get more calories out of same nutrients)

- type of gut microbes differs across populations

Slide80

A Calorie is NOT a Calorie

You could lose weight while keeping the precise tally of the calories you consume exactly the same.

However how much weight you lose depends on the biology of the plants and animals you choose to eat and who you and your microbes are Slide81

Taubes View

Fault is in the advice given by medical orthodoxy

We don’t get fat because we eat too much and move too little

We can’t solve problem or prevent it by doing the oppositeSlide82

Evidence Against

“Common sense isn’t common”Slide83

Problems

1. Fat is associated with poverty

First reported in 1960: obese women 6 times more likely to be poor than rich

2. Obesity is found in populations without so-called

obesigenic

environment

- no fast food

- no prosperitySlide84

Pima Indians 1908Slide85

“exhibit a degree of obesity that is in striking contrast with the ‘tall and sinewy’ Indian conventionalized in popular thought”

“especially well-nourished individuals … occur in every tribe … but real obesity is found almost exclusively among the Indians on the reservation”Slide86

What caused obesity??

1846: Pima were hunters and farmers

Affluent

“abundance of food”

During Gold Rush, game overhunted; water diverted

1870: living through “years of famine”

Relied on government rationsSlide87

Inactivity?

Claim: “change from past active life to … indolence”

Problems:

Women were primarily affected, yet did all hard labor

Other tribe, Pueblo, was sedentary, yet thinSlide88

Diet??

“eating everything that enters into the dietary of the white man”

Sugar, white flour

Lower in quantity than todaySlide89

Numerous Examples

Naples, 1951: “little meat…butter

unknown..half

a loaf of bread…pasta eaten everyday”

Obesity in working class, not rich

Less food available per capita than rest of Europe

Pima, 1954: 50% children obese; ‘widespread poverty”Slide90

Facts at odds with overeating hypothesis

Yet, hypothesis stands

Leads to circular arguments:

if people didn’t eat too much, they must be inactive.

If people were obviously physically active, claim they ate too much.Slide91

1. Undereating

doesn’t cure obesity

WHI Study:

20, 000 women randomly instructed to eat diet high in vegetables, fiber

Resulted in consumption of 350 fewer calories/day

Results: after eight years, lost average of 2 lbs. Waist circumference

increasedSlide92

Cognitive Dissonance?

Low calorie diet are consistently unsuccessful

Yet, experts continue to recommend them

“ reduction of energy intake continues to be the basis of successful weight reduction programs”

Few paragraphs later: results

“are known to be poor and not long-lasting”Slide93

2. Elusive Benefits of Exercise

Does increasing energy output lead to weight loss?

People who do physically demanding work are obese

Rise in obesity parallels rise of aerobics, health clubs, spinning

AHA & ACSM 2007 statement: “reasonable to assume that persons with relatively high daily energy expenditures would be less likely to gain weight… So far,

data to support this hypothesis are not particularly compelling”Slide94

Mayers Study : Claimed exercise led to weight loss

Rats forced to exercise few hours every day

Reported to eat less on those days than rats that didn’t exerciseSlide95

Actual results

But, rats ate more on days they didn’t exercise; expended less energy on those days as well

Weighed same as non-exercising rats

When they stopped exercising: ate more and gained weight with age more rapidly than sedentary ratsSlide96

Scientific vs. Popular Press

NIH, 1977:

“importance of exercise on weight control is less than might be believed because increases in energy expenditure due to exercise also tend to increase food consumption”

NYTimes

, 1977

“now strong evidence that regular exercise can ad does result in substantial and – so long as the exercise is continued

- permanent

weight loss”Slide97

3. Decreasing fat doesn’t workSlide98

1984 Food Pyramid

Eat more carbohydrates

Eat more fruits. vegetables

Eat less fat

High fat diets thought to be linked to heart disease

Thought to raise cholesterol levels ( 1970 science)

Results???Slide99

Post-Food Pyramid EffectsSlide100

Scorecard for Recommendations

Eat less: no evidence

Exercise more: no evidence

Avoid fat: increase weightSlide101

Why do we get fat?

Carbohydrates make us so; Protein and fat do not

Body fat is carefully regulated

Genetics

Sex hormones

Obesity can be caused by disruptions to regulatory process

What ever makes us fat will also make us overeatSlide102

What to do about it

Weight-loss regimens succeed when they get rid of fattening

carbs

in the diet; need sufficient fat & protein

Diets that reduce fat and protein starve the body and resultant hunger leads to failureSlide103

Questions

Isn’t fat bad for us?

Doesn’t it increase cholesterol levels?

Aren’t cholesterol levels the cause of heart attacks?Slide104

Two types of cholesterol

LDL and HDL

LDL: small, dense type associated with vascular disease

Specific Fats have different Effects

Saturated: increases HDL & LDL

Unsaturated: Increases HDL; decreases LDL

Transfat

: increase LDL; decreases HDLSlide105

What do high fat diets do?

Raise HDL

Decrease triglycerides

Make LDL “fluffier”, decreases harmful effectsSlide106

What do carb

-rich diets do?

Decrease HDL

Raise triglycerides

Make LDL small and dense- “

atherogenic

”

Garner, et al (2007) JAMASlide107

Primer on Regulation of Fat

Biological factors regulate amount of fat in our bodies

Modified by genetics

Diets can affect this processSlide108

The Basics

Why do we store fat?

Conventional view:

Long-term savings account

Body takes excess calories, stores them as fat

Stay there until you need it

Dieting

exercisingSlide109

Correct view

Fat continuously flowing out of fat cells and circulating around body to be used as fuel

If not used as fuel, returns to fat

Goes on regardless of whether we’ve recently eaten or exerciseSlide110

Cells burn carbohydrates before fat

Eat meal with both

carbs

& fat

Fat is digested, sent off to fat cells

As

carbs

are digested, they are sent to bloodstream as glucose

Cells in body burn some glucose immediately as fuel; store some for later useSlide111

Role of Insulin

Insulin secreted in anticipation of eating

Increases rate at which cells in body take in glucose

Muscle cells store some as glycogen; store some as fat

Fat cells store it as fatSlide112

Fat is used when insulin is low

As blood glucose ( and insulin) levels decrease, fat stored during meal is released for fuel

Fat is like a wallet, not savings bank: you’re always putting fat in and taking it out

In ideal world, calories stored as fat during meals are balanced by calories burned in digesting meal and overnightSlide113

How do cells decide which fat stays in fat cell and which goes?

Depends on form of fat

Fat flows in and out as “fatty acids”

Used as fuel

Small enough to flow in & out of cells

Fat is stored as “triglycerides”

Composed of 3 fatty acids

Too large to flow outSlide114

Anything that promotes fatty acid conversion to triglycerides works to make you fatter

Anything that works to break down triglycerides so they can leave cell works to make you leanerSlide115

Insulin regulates fat metabolism

Turns on mechanism in fat cells to pump in glucose

Increases glycerol molecules, which bind fatty acids into triglycerides

Works to create new fat cells to store fat Slide116

Implications

When insulin levels go up, we store fat; when they go down, we mobilize fat and use it for fuel.

Suggests that anything that makes us secrete more insulin will extend periods during which we store fat and shorten the periods we burn itSlide117

Results

Obesity

Hunger

Can’t use carbohydrates stored in liver and muscle for fuel

Vicious cycle:

bodies getting bigger, so we need more fuel

Energy demands increase, as does appetite