1. Mexico: Highest Obesity in World

2. 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”

3. “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.”

4. 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.

5. 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”

6. 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.

7. Usual Recommendations For Losing Weight
Eat fewer calories
Exercise more
Avoid fat

8. Gary Taubes: The Man who shows conventional wisdom is wrong

9. Yet, no evidence this works
1960: 1/9 Americans obese
2010: 1/3 Americans obese
2/3 Overweight
Childhood obesity skyrocketing

10. 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”

11. 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 willpower

12. What actually happens when people try to diet?

13. It’s not just about calories
Why diets don’t work
It’s not just about calories

14. 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 weeks

15. 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 food

16. 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 hunger

17. 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: hungrier

18. 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 weight

19. 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 Phase

20. 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 food

21. 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.

22. 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:

23. 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 week

24. 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 explanation

25. 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 gain

26. Bouchard & Tremblay Twin Studies
Genetic Factors in Weight Control

27. 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 gained

28. Results
Weight gain similar between brothers, but varied considerably between pairs
pounds
Pattern of fat distribution also similar between brothers, but varied between pairs
Some gained 3 times as much around abdomen

29. 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 two

30. FTO Gene Effects

31. 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 study

32. Losing Weight is Hard

33. People Can Do It

34. 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 years

35. 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)

36. Dieting Changes Brain Activity
After Weight loss
Bigger response in brain activity in reward centers
Lower response in areas associated with control

37. 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-loss

38. All Calories not the same( NYTimes, 4/15/2012)

39. 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 hunger

40. Are All Calories Actually Equal??

41. 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”

46. Big Food Angle To Calorie Argument
Accept that, and you buy into the contention that consuming 100 calories’ worth of sugar water (like Coke or Gatorade), white bread or French fries is the same as eating 100 calories of broccoli or beans. And Big Food — which has little interest in selling broccoli or beans — would have you believe that if you expend enough energy to work off those 100 calories, it simply doesn’t matter.

47. 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.”

48. Promotes idea that all calories are equal

49. Evidence Against “ Calorie is a Calorie”

50. All foods are not equal

51. 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 orange

52. 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 times as much heat-energy to digest as fats.
Well-done meat > raw/rare meat

53. Carmody, et al., 2011

54. 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.

55. 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?

56. Results Didn’t differ in level of activity
Did differ in how much they weighed at end of study

57. Changes in body mass on tuber diets.
Changes in body mass on tuber diets. Mean cumulative change in body mass [±95% confidence interval (CI)] over 4 d in mice (n = 17) fed standardized ad libitum diets of organic sweet potato (I. batatas) served raw and whole (RW), raw and pounded (RP), cooked and whole (CW), and cooked and pounded (CP). Diets were administered based on a counterbalanced within-subjects study design.
Carmody R N et al. PNAS 2011;108:
©2011 by National Academy of Sciences

58. Food preferences on tuber diets.
Food preferences on tuber diets. Relative preferences among mice (n = 17) in the naïve (before exposure to any tuber diet) and experienced (after exposure to all tuber diets) conditions for organic sweet potato (I. batatas) served raw and whole (RW), raw and pounded (RP), cooked and whole (CW), and cooked and pounded (CP). Values shown reflect composite data from the two metrics of preference used in this study: first bite (diet consumed first given concurrent presentation of all diets) and total intake (grams consumed in 3 h corrected for desiccation). The composite value for a given diet is calculated as the average of the percentage of first bites and the percentage of total intake attributable to that diet. Naïve mice strongly preferred pounded tuber treatments (composite value χ2; cooking: P = 0.489, pounding: P < 0.001), whereas experienced mice strongly preferred cooked tuber treatments (composite value χ2; cooking: P < 0.001, pounding: P = 0.519).
Carmody R N et al. PNAS 2011;108:
©2011 by National Academy of Sciences

59. Changes in body mass on meat diets.
Changes in body mass on meat diets. Mean cumulative change in body mass (±95% CI) over 4 d in mice (n = 16) fed standardized ad libitum diets of organic beef (B. taurus) eye round served raw and whole (RW), raw and pounded (RP), cooked and whole (CW), and cooked and pounded (CP). Diets were administered based on a counterbalanced within-subjects study design.
Carmody R N et al. PNAS 2011;108:
©2011 by National Academy of Sciences

60. Food preferences on meat diets.
Food preferences on meat diets. Relative preferences among mice (n = 16) in the naïve (before exposure to any meat diet) and experienced (after exposure to all meat diets) conditions for organic beef (B. taurus) eye round served raw and whole (RW), raw and pounded (RP), cooked and whole (CW), and cooked and pounded (CP). Values shown reflect composite data from the two metrics of preference used in this study: first bite (diet consumed first given concurrent presentation of all diets) and total intake (grams consumed in 3 h corrected for desiccation). The composite value for a given diet is calculated as the average of the percentage of first bites and the percentage of total intake attributable to that diet. Mice preferred cooked meat diets in both the naïve condition (composite value χ2; cooking: P < 0.001, pounding: P = 0.049) and experienced condition (composite value χ2; cooking: P < 0.001, pounding: P = 0.386).
Carmody R N et al. PNAS 2011;108:
©2011 by National Academy of Sciences

61. 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 raw

62. What about Industrial Processing?

63. Sadie, et al, 2010

64. 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)

65. Measured:
energy expended to digest it for 5-6 hrs post meal (post-prandial energy expenditure)
Satiety ( how full they felt)

66. Comparison of two meals

67. Results

68. 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 satiety

69. Food Composition of Diet Matters

70. Clinical trial comparing weight loss diets
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 same

71. 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 & protein

72. 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.

73. On the very low-carbohydrate diet, Dr
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 diet

74. 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

75. Conclusion
nutrient composition of the diet can trigger the predisposition to get fat, independent of the calories consumed.

76. 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.”

77. 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.

78. 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 diets

79. 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

80. 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

81. 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 opposite

82. “Common sense isn’t common”
Evidence Against
“Common sense isn’t common”

83. 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 prosperity

84. Pima Indians 1908

85. “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”

86. 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 rations

87. 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 thin

88. Diet??
“eating everything that enters into the dietary of the white man”
Sugar, white flour
Lower in quantity than today

89. 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”

90. 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.

91. 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 increased

92. 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”

93. 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 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”

94. 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 exercise

95. 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 rats

96. 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”

97. 3. Decreasing fat doesn’t work

98. 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???

99. Post-Food Pyramid Effects

100. Scorecard for Recommendations
Eat less: no evidence
Exercise more: no evidence
Avoid fat: increase weight

101. 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 overeat

102. 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 failure

103. Questions Isn’t fat bad for us?
Doesn’t it increase cholesterol levels?
Aren’t cholesterol levels the cause of heart attacks?

104. 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 HDL

105. What do high fat diets do?
Raise HDL
Decrease triglycerides
Make LDL “fluffier”, decreases harmful effects

106. What do carb-rich diets do?
Decrease HDL
Raise triglycerides
Make LDL small and dense- “atherogenic”
Garner, et al (2007) JAMA

107. Primer on Regulation of Fat
Biological factors regulate amount of fat in our bodies
Modified by genetics
Diets can affect this process

108. 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
exercising

109. 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 exercise

110. 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 use

111. 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 fat

112. 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 overnight

113. 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 out

114. 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 leaner

115. 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

116. 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 it

117. Results Obesity Hunger Vicious cycle:
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