Honey, we blew up the kids! Contributions of the food and built environments to the current childhood obesity epidemic

Transcription

1 Honey, we blew up the kids! Contributions of the food and built environments to the current childhood obesity epidemic Robert Lustig, M.D. Division of Endocrinology Department of Pediatrics UCSF Richard Jackson, M.D., M.P.H. Chairman, Dept. of Environmental Health UCLA Childhood Obesity 2010, Milton Marks Auditorium, Feb. 27, 2010

2 No disclosures for Drs. Lustig or Jackson

3 The First Law of Thermodynamics

4 The First Law of Thermodynamics Calories In

5 The First Law of Thermodynamics Calories Out Calories In

6 The First Law of Thermodynamics Weight Gain Calories Out Calories In

7 The First Law of Thermodynamics Weight Gain Calories Out Calories In

8 Just a caloric bachanalia?

9 Just a caloric bachanalia? +187 kcal/d (men), +335 kcal/d (women), +275 kcal/d (teens) In last 25 years CDC, 2005

10 Behavior? Personal responsibility?

11 Behavior? Personal responsibility? Three reasons to doubt this formulation: 1. No child chooses to obese. The quality of life of an obese child is equivalent to those on cancer chemotherapy. (Schwimmer et al. JAMA 289: , 2003)

12 2. Summary of meta-analyses results of randomized trials of treatments for pediatric obesity CONCLUSIONS: Limited evidence supports the short-term efficacy of medications and lifestyle interventions. The long-term efficacy and safety of pediatric obesity treatments remain unclear. McGovern et al. J Clin Endocrinol Metab 93::4600, 2008

13 2. Summary of meta-analyses results of randomized trials of treatments for pediatric obesity Epstein? CONCLUSIONS: Limited evidence supports the short-term efficacy of medications and lifestyle interventions. The long-term efficacy and safety of pediatric obesity treatments remain unclear. McGovern et al. J Clin Endocrinol Metab 93::4600, 2008

14 2. Exercise for treatment of obesity Main results: The 43 studies included 3476 participants. When compared with no treatment, exercise resulted in small weight losses across studies. Exercise combined with diet resulted in a greater weight reduction than diet alone (WMD kg; 95% confidence interval (CI) -1.3 to -0.7). Increasing exercise intensity increased the magnitude of weight loss (WMD kg; 95% CI -2.3 to -0.7). Shaw et al. Cochrane Reviews 2006, Issue 4: CD DOI: / CD pub3.

15 2. Summary of meta-analyses results of randomized trials of preventions for pediatric obesity CONCLUSION: Pediatric obesity prevention programs caused small changes in target behaviors and no significant effect on BMI compared with control. Trials evaluating promising interventions applied over a long period, using responsive outcomes, with longer measurement timeframes are urgently needed. Kamath et al. J Clin Endocrinol Metab 93:4606, 2008

16 3. We even have an epidemic of obese 6-month olds They don t t exhibit any of these behaviors (Kim et al, Obesity 15:1107, 2006) So any hypothesis that attempts to explain the obesity epidemic, must be able to explain this as well

17 Behavior Stedmanʼs s Medical Dictionary Def. A stereotyped motor response to a physiological stimulus

18 Behavior Stedmanʼs s Medical Dictionary Def. A stereotyped motor response to a physiological stimulus Corollary: Behavior has a biochemical basis

19 Behavior Stedmanʼs s Medical Dictionary Def. A stereotyped motor response to a physiological stimulus Corollary: Behavior has a biochemical basis What are the biochemical underpinnings of gluttony and sloth?

20 Three reasons to eat Hunger (insulin) Reward (dopamine) Stress (cortisol)

21 The toxic environment Modern eating and exercise conditions Food: Activity: Available 24 hours/day Decreased walking and biking Accessible as never before Little P.E. Sold in places unrelated to eating Screen time makes kids inactive Cheap Parents reluctant to let children Promoted heavily play outside for fear of crime Designed to taste really good to keep people eating Brownell and Horgen, Food Fight, McGraw-Hill, New York, 2004, ISBN

22 The toxic environment (as Brownell defines it) is a euphemism for our altered behaviors

23 The toxic environment (as Brownell defines it) is a euphemism for our altered behaviors Is there something truly poisonous in our current environment, causing the obesity epidemic?

24 Can exposure to environmental toxins cause obesity? (Gordon Conference, 2006) (AAAS Symposium, 2007) Estrogens (DES, bisphenol-a, genistein) Phthalates (Monobutyryl phthalate, DEHP) Organochlorines (atrazine, trans-nonachlor, oxychlordane) Dioxins and polychlorinated biphenyls Organotins (tributyltin, triphenyltin) Our diet?

25 Total Caloric Intake 275 kcal in teen boys Children 2-17 yrs, CSFII (USDA) vs

26 Fat Intake: Grams 5 g (45 cal) in teen boys Children 2-17 yrs, CSFII (USDA) vs

27 Secular trends in specific food intake Chanmugam et al. J Am Diet Assoc 103:867, 2003

28 Secular trends in specific food intake Fats Chanmugam et al. J Am Diet Assoc 103:867, 2003

29 Prevalence of Obesity Compared to Percent Calories from Fat Among U.S. Adults Percent Year

30 Carbohydrate Intake: Grams 57 g (228 cal) in teen boys Children 2-17 yrs, CSFII (USDA) vs

31 Secular trends in specific food intake Fats CHO Chanmugam et al. J Am Diet Assoc 103:867, 2003

32 Beverage Intake 41% soft drinks 35% fruit drinks Children 2-17 yrs, CSFII (USDA) vs

33 Beverage Intake 41% soft drinks 35% fruit drinks Children 2-17 yrs, CSFII (USDA) vs One can of soda/day = 150 cal x 365 d/yr 3500 cal/lb = 15.6 lbs/yr!

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35 Meta-Analysis of Soft Drinks and Obesity 88 cross-sectional and longitudinal studies regressing soft drink consumption with energy intake r = 0.16 (P < 0.001) body weight r = 0.08 (P < 0.001) milk and calcium intake r = (P < 0.001) adequate nutrition r = (P < 0.001) Those studies funded by the beverage industry demonstrated smaller effects than independent studies Vartanian et al. Am J Public Health 97:667, 2007

36 Curtailing soft drinks limits childhood obesity Obesity Prevalence (%) James et al. BMJ 328:1237, 2004

37 High Fructose Corn Syrup Current US annual consumption of HFCS 63 pounds per person

38 Relative sweetness of various carbohydrates Fructose 173 invert sugar* 120 HFCS (42-55% fructose) 120 Sucrose 100 Xylitol 100 Tagatose 92 Glucose 74 high-de corn syrup 70 Sorbitol 55 Mannitol 50 Trehalose 45 regular corn syrup 40 Galactose 32 Maltose 32 Lactose 15

39 High Fructose Corn Syrup is 42-55% Fructose; Sucrose is 50% Fructose Glucose Fructose Sucrose

40 Press Release, February 6, 2008 Unlikely Duo Opposes San Francisco Soft Drink Tax Plan Corn Refiners and CSPI Agree High-Fructose Corn Syrup No Worse Than Sugar WASHINGTON The nonprofit Center for Science in the Public Interest has long supported small taxes on soft drinks to help pay for bike paths, nutrition education, and other obesity-prevention programs. But CSPI opposes a measure proposed by San Francisco Mayor Gavin Newsom because it would tax only drinks made with high-fructose corn syrup and not drinks made with other forms of sugar. Less surprisingly, the Corn Refiners Association also opposes the measure, but the two groups cosigned an unusual joint letter to Mayor Newsom urging him to reconsider his plan. We respectfully urge that the proposal be revised as soon as possible to reflect the scientific evidence that demonstrates no material differences in the health effects of high-fructose corn syrup and sugar, wrote CSPI executive director Michael F. Jacobson and Corn Refiners Association president Audrae Erickson. The real issue is that excessive consumption of any sugars may lead to health problems. The letter goes on to explain that high-fructose corn syrup and sucrose, or table sugar, are similar in composition and that several studies have shown that the two types of sugars are similarly metabolized by the body.

41 Secular trend in fructose consumption Natural consumption of fruits and vegetables 15 gm/day Prior to WWII (estimated): gm/day (USDA Nationwide Food Consumption Survey): 37 gm/day (8% of total caloric intake) 1994 (NHANES III): 54.7 gm/day (10.2% of total caloric intake) Adolescents: 72.8 gm/day (12.1% of total caloric intake) 25% consumed at least 15% of calories from fructose Bray, Am J Clin Nutr 86:895, 2007; Vos et al. Medscape Med J 10:160, 2008

42 The perfect storm from three political winds

43 The perfect storm from three political winds 1. Richard Nixon and USDA Secretary Earl Butz (1973) food should never be an issue in a presidential election

44 The perfect storm from three political winds 1. Richard Nixon and USDA Secretary Earl Butz (1973) food should never be an issue in a presidential election 2. The advent of High Fructose Corn Syrup invented in 1966 in Japan introduced to the American market in 1975

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46 Sucrose High Fructose Corn Syrup

47 Juice is sucrose: Change in BMI z-score in lower socioeconomic status children versus number of fruit juice servings per day Faith MS et al. Pediatrics 118:2066, 2006

48 MOST FRUCTOSE ITEMS Sucrose JUICE High Fructose Corn Syrup

49 The perfect storm from three political winds 1. Richard Nixon and USDA Secretary Earl Butz (1973) food should never be an issue in a presidential election 2. The advent of High Fructose Corn Syrup invented in 1966 in Japan introduced to the American market in The USDA, AMA, and AHA call for dietary fat reduction Early 1970 s: discovery of LDL Mid 1970 s: Dietary fat raises LDL (A B) Late 1970 s: LDL correlated with CVD (B C) 1982: If A B, and B C, then A C, therefore no A, no C

50 The macronutrient wars , 1986

51 Seven Countries Correlation of CHD with dietary fat

52 Seven Countries Correlation of CHD with dietary fat Page 262: Diet

53 The low-fat craze The content of low-fat home-cooked food can be controlled But low-fat processed food means substitution with carbohydrate Which carbohydrate? Either High fructose corn syrup (55% fructose) Sucrose (50% fructose) e.g. Nabisco Snackwells Oreos ( 2g fat, +13g CHO (+4g sugars))

54 Adulteration of our food supply Addition of fructose palatability (esp. with decreased fat) browning agent Removal of fiber shelf life freezing Substitution of trans-fats hardening agent, shelf life now being removed due to CVD risk

55 Fructose is not glucose Fructose is 7 times more likely than glucose to form Advanced Glycation End-Products (AGE s) Fructose does not suppress ghrelin Acute fructose does not stimulate insulin (or leptin) Hepatic fructose metabolism is different Chronic fructose exposure promotes the Metabolic Syndrome Elliot et al. Am J Clin Nutr, 2002 Bray et al. Am J Clin Nutr, 2004 Teff et al. J Clin Endocrinol Metab, 2004 Gaby, Alt Med Rev, 2005 Le and Tappy, Curr Opin Clin Nutr Metab Care, 2006 Wei et al. J Nutr Biochem, 2006

56 24 kcal Hepatocyte 96 kcal

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64 Ethanol is a carbohydrate

65 Ethanol is a carbohydrate CH 3 -CH 2 -OH

66 Ethanol is a carbohydrate CH 3 -CH 2 -OH But ethanol is also a toxin

67 Acute ethanol exposure Acute fructose exposure CNS depression Vasodilatation, decreased BP Hypothermia Tachycardia Myocardial depression Variable pupillary responses Respiratory depression Diuresis Hypoglycemia Loss of fine motor control

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79 60 kcal (+ 12 kcal glucose) 48 kcal

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95 Chronic ethanol exposure Hematologic disorders Electrolyte abnormalities Hypertension Cardiac dilatation Cardiomyopathy Dyslipidemia Pancreatitis Malnutrition Obesity Hepatic dysfunction (ASH) Fetal alcohol syndrome Addiction

96 Chronic ethanol exposure Chronic fructose exposure Hematologic disorders Electrolyte abnormalities Hypertension Hypertension Cardiac dilatation Cardiomyopathy Dyslipidemia Pancreatitis Myocardial infarction Dyslipidemia Pancreatitis (2 o dyslipidemia) Malnutrition Obesity Hepatic dysfunction (ASH) Fetal alcohol syndrome Addiction Obesity Hepatic dysfunction (NASH) Fetal insulin resistance Habituation, if not addiction

97 What s s the difference? Calories Percent CHO 10.5% (sucrose) 3.6% (alcohol) Calories from fructose 75 (4.1 kcal/gm) other carbs 75 (glucose) 60 (maltose) alcohol 90 (7 kcal/gm) 1st pass GI metabolism 0% 10% Calories reaching liver 90 92

98 What s s the difference? Calories Percent CHO 10.5% (sucrose) 3.6% (alcohol) Calories from fructose 75 (4.1 kcal/gm) other carbs 75 (glucose) 60 (maltose) alcohol 90 (7 kcal/gm) 1st pass GI metabolism 0% 10% Calories reaching liver 90 92

99 What s s the difference? Calories Percent CHO 10.5% (sucrose) 3.6% (alcohol) Calories from fructose 75 (4.1 kcal/gm) other carbs 75 (glucose) 60 (maltose) alcohol 90 (7 kcal/gm) 1st pass GI metabolism 0% 10% Calories reaching liver 90 92

100 Fructose is a carbohydrate

101 Fructose is a carbohydrate Fructose is metabolized like fat

102 Fructose is a carbohydrate Fructose is metabolized like fat (corollary: a low fat diet isn t really low fat, because the fructose/sucrose doubles as fat)

103 Fructose is a carbohydrate Fructose is metabolized like fat Fructose is also a toxin

104 Could this be the reason for obesity in 6-month olds? INGREDIENTS (Powder) 43.2% Corn syrup solids, 14.6% soy protein isolate (genistein), 11.5% high oleic safflower oil, 10.3% sugar (sucrose), 8.4% soy oil, 8.1% coconut oil Plus a baby bottle (bisphenol-a) Courtesy of M. Walker

105 Recognition at the AHA Recommends reduction in sugar intake from 22 tsp/day to 9 tsp/day (males) and 6 tsp/day (females) Circulation 120:1011, 2009

106 Why is exercise important in obesity? Because it burns calories?

107 Why is exercise important in obesity? Because it burns calories? Because it improves skeletal muscle insulin sensitivity Because it reduces stress, and resultant cortisol release Because it makes the TCA cycle run faster, and detoxifies fructose, improving hepatic insulin sensitivity

108 So what s s with Colorado?

109 So what s s with Colorado? Four factors increase the hepatic TCA cycle Cold Altitude Thyroid hormone Exercise

110 Why is fiber important in obesity?

111 Why is fiber important in obesity? When G-d made the poison, he packaged it with the antidote.

112 Why is fiber important in obesity? When G-d made the poison, he packaged it with the antidote. Fiber: 1. Reduces rate of intestinal carbohydrate absorption, reducing insulin response 2. Increases speed of transit of intestinal contents to ileum, to raise PYY 3-36, and induce satiety 3. Inhibits absorption of some free fatty acids to the colon, which are metabolized by colonic bacteria to shortchain fatty acids (SCFA), which suppress insulin

113 Diet is about pounds Exercise is about inches Diet is about weight Exercise is about health

114 The First Law of Thermodynamics

115 The First Law of Thermodynamics Weight Gain

116 The First Law of Thermodynamics Weight Gain Calories Out

117 The First Law of Thermodynamics Weight Gain Calories Out Calories In

118 Mietus-Snyder and Lustig, Ann Rev Med 59:147, 2008 The limbic triangle

119 Summary The toxic environment is not just a euphemism We are all exposed to environmental obesogens; the most important is sugar Hunger, reward, and stress all drive excessive food, esp. fructose, consumption Hepatic fructose metabolism promotes all manifestations of the Metabolic Syndrome: hypertension de novo lipogenesis, dyslipidemia, and hepatic steatosis inflammation hepatic insulin resistance obesity CNS leptin resistance, promoting continuous consumption Fructose qualifies as a chronic dose-dependent hepatotoxin; it s alcohol without the buzz Eat less doesn t work; but eat less sugar does (most of the time) Behavioral change is difficult (reward, stress are tough to undo) Environmental change is also difficult, but possible, and essential

120 Collaborators UCSF Dept. of Pediatrics Michele Mietus-Snyder, M.D. Andrea Garber, Ph.D., R.D. Joan Valente, Ph.D./Lisa Groesz, Ph.D. Kristine Madsen, M.D., M.P.H. Patrika Tsai, M.D., M.P.H. Stephanie Nguyen, M.D., M.A.S. Carolyn Jasik, M.D., M.P.H. Clement Cheung, M.D., Ph.D. UCSF Dept. of Epidemiology and Biostatistics Ann Lazar, Ph.D. Peter Bacchetti, Ph.D. Saunak Sen, Ph.D. UC Berkeley Dept. of Nutritional Sciences Jean-Marc Schwarz, Ph.D. Brenda Eskenasi, Ph.D. Sharon Fleming, Ph.D. Lorene Ritchie, Ph.D.