1.Nahmias E, Morris S, Nadelhoffer T et al. (2005) Surveying freedom: folk intuitions about free will and moral responsibility. Philos Psychol 18, 561–584.
3.Caballero B (2007) The global epidemic of obesity: an overview. Epidemiol Rev 29, 1–5.
5.Hamilton MT, Hamilton DG & Zderic TW (2007) Role of low energy expenditure and sitting in obesity, metabolic syndrome, type 2 diabetes, and cardiovascular disease. Diabetes 56, 2655–2667.
6.Heath GW (2009) Physical activity transitions and chronic disease. Am J Lifestyle Med 3, issue 1, 27S–31S.
7.Levine JA & Miller JM (2007) The energy expenditure of using a ‘walk-and-work’ desk for office workers with obesity. Br J Sports Med 41, 558–561.
8.Millward DJ (2010) Energy expenditure and the obesity epidemic. Am J Clin Nutr 91, 1801–1802.
9.Goran MI & Treuth MS (2001) Energy expenditure, physical activity, and obesity in children. Pediatr Clin North Am 48, 931–953.
10.Ravussin E, Lillioja S, Knowler WC et al. (1988) Reduced rate of energy expenditure as a risk factor for body-weight gain. N Engl J Med 318, 467–472.
11.Westerterp KR & Speakman JR (2008) Physical activity energy expenditure has not declined since the 1980s and matches energy expenditures of wild mammals. Int J Obes (Lond) 32, 1256–1263.
13.Bruce MJ & Katzmarzyk PT (2002) Canadian population trends in leisure-time physical activity levels, 1981–1998. Can J Appl Physiol 27, 681–690.
14.Petersen CB, Thygesen LC, Helge JW et al. (2010) Time trends in physical activity in leisure time in the Danish population from 1987 to 2005. Scand J Public Health 38, 121–128.
15.Steffen LM, Arnett DK, Blackburn H et al. (2006) Population trends in leisure-time physical activity: Minnesota Heart Survey, 1980–2000. Med Sci Sports Exerc 38, 1716–1723.
16.Talbot LA, Fleg JL & Metter EJ (2003) Secular trends in leisure-time physical activity in men and women across four decades. Prev Med 37, 52–60.
17.Hall KD, Guo J, Dore M et al. (2009) The progressive increase of food waste in America and its environmental impact. PLoS One 4, e7940.
18.Flegal KM, Graubard BI, Williamson DF et al. (2005) Excess deaths associated with underweight, overweight, and obesity. JAMA 293, 1861–1867.
19.Potier M, Darcel N & Tome D (2009) Protein, amino acids and the control of food intake. Curr Opin Clin Nutr Metab Care 12, 54–58.
20.Strazzullo P, D'Elia L, Cairella G et al. (2010) Excess body weight and incidence of stroke: meta-analysis of prospective studies with 2 million participants. Stroke 41, e418–e426.
21.Fantuzzi G & Mazzone T (2007) Adipose tissue and atherosclerosis: exploring the connection. Arterioscler Thromb Vasc Biol 27, 996–1003.
22.Kotsis V, Stabouli S, Bouldin M et al. (2005) Impact of obesity on 24-hour ambulatory blood pressure and hypertension. Hypertension 45, 602–607.
23.Kahn SE, Hull RL & Utzschneider KM (2006) Mechanisms linking obesity to insulin resistance and type 2 diabetes. Nature 444, 840–846.
24.Leveille SG, Wee CC & Iezzoni LI (2005) Trends in obesity and arthritis among baby boomers and their predecessors, 1971–2002. Am J Public Health 95, 1607–1613.
25.Pischon T, Nothlings U & Boeing H (2008) Obesity and cancer. Proc Nutr Soc 67, 128–145.
27.Levy DT, Mabry PL, Wang YC et al. (2011) Simulation models of obesity: a review of the literature and implications for research and policy. Obes Rev 12, 378–394.
28.Hill JO (2009) Can a small-changes approach help address the obesity epidemic? A report of the Joint Task Force of the American Society for Nutrition, Institute of Food Technologists, and International Food Information Council. Am J Clin Nutr 89, 477–484.
29.Werner WB, Feonstein AH & Hardigree CE (2007) The risk to the American fast-food industry of obesity litigation. Cornell Hotel Restaurant Admin Q 48, 201–214.
31.Bish CL, Blanck HM, Serdula MK et al. (2005) Diet and physical activity behaviors among Americans trying to lose weight: 2000 Behavioral Risk Factor Surveillance System. Obes Res 13, 596–607.
32.Zhao G, Ford ES, Li C et al. (2009) Weight control behaviors in overweight/obese US adults with diagnosed hypertension and diabetes. Cardiovasc Diabetol 8, 13.
33.Andreyeva T, Long MW, Henderson KE et al. (2010) Trying to lose weight: diet strategies among Americans with overweight or obesity in 1996 and 2003. J Am Diet Assoc 110, 535–542.
34.Anderson JW, Konz EC, Frederich RC et al. (2001) Long-term weight-loss maintenance: a meta-analysis of US studies. Am J Clin Nutr 74, 579–584.
35.Inelmen EM, Toffanello ED, Enzi G et al. (2005) Predictors of drop-out in overweight and obese outpatients. Int J Obes (Lond) 29, 122–128.
36.Finley CE, Barlow CE, Greenway FL et al. (2007) Retention rates and weight loss in a commercial weight loss program. Int J Obes (Lond) 31, 292–298.
37.Sjostrom L, Lindroos AK, Peltonen M et al. (2004) Lifestyle, diabetes, and cardiovascular risk factors 10 years after bariatric surgery. N Engl J Med 351, 2683–2693.
38.Maggard MA, Shugarman LR, Suttorp M et al. (2005) Meta-analysis: surgical treatment of obesity. Ann Intern Med 142, 547–559.
39.Poitou Bernert C, Ciangura C, Coupaye M et al. (2007) Nutritional deficiency after gastric bypass: diagnosis, prevention and treatment. Diabetes Metab 33, 13–24.
40.Imaz I, Martinez-Cervell C, Garcia-Alvarez EE et al. (2008) Safety and effectiveness of the intragastric balloon for obesity. A meta-analysis. Obes Surg 18, 841–846.
41.Goldstein DJ (1992) Beneficial health effects of modest weight loss. Int J Obes Relat Metab Disord 16, 397–415.
42.Heymsfield SB, van Mierlo CA, van der Knaap HC et al. (2003) Weight management using a meal replacement strategy: meta and pooling analysis from six studies. Int J Obes Relat Metab Disord 27, 537–549.
43.Davis LM, Coleman C, Kiel J et al. (2010) Efficacy of a meal replacement diet plan compared to a food-based diet plan after a period of weight loss and weight maintenance: a randomized controlled trial. Nutr J 9, 11.
44.Annunziato RA, Timko CA, Crerand CE et al. (2009) A randomized trial examining differential meal replacement adherence in a weight loss maintenance program after one-year follow-up. Eat Behav 10, 176–183.
45.Barnes A, Goodrick K, Pavlik VN et al. (2009) A pilot study using partial meal replacement for weight loss in low-income patients. J Gen Intern Med 24, 7–8.
46.Cabanillas M, Moya Chimenti E, Gonzalez Candela C et al. (2009) Usefulness of meal replacement: analysis of the principal meal replacement products commercialised in Spain. Nutr Hosp 24, 535–542.
47.Lee K, Lee J, Bae WK et al. (2009) Efficacy of low-calorie, partial meal replacement diet plans on weight and abdominal fat in obese subjects with metabolic syndrome: a double-blind, randomised controlled trial of two diet plans – one high in protein and one nutritionally balanced. Int J Clin Pract 63, 195–201.
48.Heber D, Ashley JM, Wang HJ et al. (1994) Clinical evaluation of a minimal intervention meal replacement regimen for weight reduction. J Am Coll Nutr 13, 608–614.
49.Ditschuneit HH, Flechtner-Mors M, Johnson TD et al. (1999) Metabolic and weight-loss effects of a long-term dietary intervention in obese patients. Am J Clin Nutr 69, 198–204.
50.Flechtner-Mors M, Ditschuneit HH, Johnson TD et al. (2000) Metabolic and weight loss effects of long-term dietary intervention in obese patients: four-year results. Obes Res 8, 399–402.
51.Mattes RD (2002) Ready-to-eat cereal used as a meal replacement promotes weight loss in humans. J Am Coll Nutr 21, 570–577.
52.Vander Wal JS, McBurney MI, Cho S et al. (2007) Ready-to-eat cereal products as meal replacements for weight loss. Int J Food Sci Nutr 58, 331–340.
53.Wing RR, Jeffery RW, Burton LR et al. (1996) Food provision vs structured meal plans in the behavioral treatment of obesity. Int J Obes Relat Metab Disord 20, 56–62.
54.McCarron DA & Reusser ME (2001) Reducing cardiovascular disease risk with diet. Obes Res 9, Suppl. 4, 335S–340S.
55.Metz JA, Stern JS, Kris-Etherton P et al. (2000) A randomized trial of improved weight loss with a prepared meal plan in overweight and obese patients: impact on cardiovascular risk reduction. Arch Intern Med 160, 2150–2158.
56.Gorin AA, Raynor HA, Niemeier HM et al. (2007) Home grocery delivery improves the household food environments of behavioral weight loss participants: results of an 8-week pilot study. Int J Behav Nutr Phys Act 4, 58.
57.Hannum SM, Carson L, Evans EM et al. (2004) Use of portion-controlled entrees enhances weight loss in women. Obes Res 12, 538–546.
58.Gucciardi E, Demelo M, Lee RN et al. (2007) Assessment of two culturally competent diabetes education methods: individual versus individual plus group education in Canadian Portuguese adults with type 2 diabetes. Ethn Health 12, 163–187.
59.Renjilian DA, Perri MG, Nezu AM et al. (2001) Individual versus group therapy for obesity: effects of matching participants to their treatment preferences. J Consult Clin Psychol 69, 717–721.
60.Ashley JM, St Jeor ST, Schrage JP et al. (2001) Weight control in the physician's office. Arch Intern Med 161, 1599–1604.
61.Martin CK, Talamini L, Johnson A et al. (2010) Weight loss and retention in a commercial weight-loss program and the effect of corporate partnership. Int J Obes (Lond) 34, 742–750.
62.Smith DE, Heckemeyer CM, Kratt PP et al. (1997) Motivational interviewing to improve adherence to a behavioral weight-control program for older obese women with NIDDM. A pilot study. Diabetes Care 20, 52–54.
63.West DS, DiLillo V, Bursac Z et al. (2007) Motivational interviewing improves weight loss in women with type 2 diabetes. Diabetes Care 30, 1081–1087.
64.Lowe MR, Miller-Kovach K & Phelan S (2001) Weight-loss maintenance in overweight individuals one to five years following successful completion of a commercial weight loss program. Int J Obes Relat Metab Disord 25, 325–331.
65.Lowe MR, Kral TVE & Miller-Kovach K (2008) Weight-loss maintenance 1, 2 and 5 years after successful completion of a weight-loss programme. Br J Nutr 99, 925–930.
66.National Task Force on the Prevention and Treatment of Obesity (2000) Dieting and the development of eating disorders in overweight and obese adults. Arch Intern Med 160, 2581–2589.
67.Lutz TA (2009) Control of food intake and energy expenditure by amylin – therapeutic implications. Int J Obes (Lond) 33, Suppl. 1, S24–S27.
68.Moran TH (2009) Gut peptides in the control of food intake. Int J Obes (Lond) 33, Suppl. 1, S7–S10.
69.Beckers S, Zegers D, Van Gaal LF et al. (2009) The role of the leptin–melanocortin signalling pathway in the control of food intake. Crit Rev Eukaryot Gene Expr 19, 267–287.
70.Woods SC (2009) The control of food intake: behavioral versus molecular perspectives. Cell Metab 9, 489–498.
71.Goel MS, McCarthy EP, Phillips RS et al. (2004) Obesity among US immigrant subgroups by duration of residence. JAMA 292, 2860–2867.
72.Kaplan MS, Huguet N, Newsom JT et al. (2004) The association between length of residence and obesity among Hispanic immigrants. Am J Prev Med 27, 323–326.
73.Cairney J & Ostbye T (1999) Time since immigration and excess body weight. Can J Public Health 90, 120–124.
75.Levitsky DA & DeRosimo L (2010) One day of food restriction does not result in an increase in subsequent daily food intake in humans. Physiol Behav 99, 495–499.
76.Heilbronn LK, Smith SR, Martin CK et al. (2005) Alternate-day fasting in nonobese subjects: effects on body weight, body composition, and energy metabolism. Am J Clin Nutr 81, 69–73.
77.Rolls BJ, Roe LS & Meengs JS (2006) Reductions in portion size and energy density of foods are additive and lead to sustained decreases in energy intake. Am J Clin Nutr 83, 11–17.
78.Rolls BJ, Morris EL & Roe LS (2002) Portion size of food affects energy intake in normal-weight and overweight men and women. Am J Clin Nutr 76, 1207–1213.
79.Rolls BJ, Roe LS, Kral TV et al. (2004) Increasing the portion size of a packaged snack increases energy intake in men and women. Appetite 42, 63–69.
80.Kral TV, Roe LS & Rolls BJ (2004) Combined effects of energy density and portion size on energy intake in women. Am J Clin Nutr 79, 962–968.
81.Mattes R (1990) Hunger ratings are not a valid proxy measure of reported food intake in humans. Appetite 15, 103–113.
82.Diliberti N, Bordi PL, Conklin MT et al. (2004) Increased portion size leads to increased energy intake in a restaurant meal. Obes Res 12, 562–568.
83.Fisher JO, Arreola A, Birch LL et al. (2007) Portion size effects on daily energy intake in low-income Hispanic and African American children and their mothers. Am J Clin Nutr 86, 1709–1716.
84.Jeffery RW, Rydell S, Dunn CL et al. (2007) Effects of portion size on chronic energy intake. Int J Behav Nutr Phys Act 4, 27.
85.Levitsky DA & Youn T (2004) The more food young adults are served, the more they overeat. J Nutr 134, 2546–2549.
86.Levitsky DA, Obarzanek E, Mrdjenovic G et al. (2005) Imprecise control of energy intake: absence of a reduction in food intake following overfeeding in young adults. Physiol Behav 84, 669–675.
87.Rolls BJ, Roe LS & Meengs JS (2006) Larger portion sizes lead to a sustained increase in energy intake over 2 days. J Am Diet Assoc 106, 543–549.
88.Kelly MT, Wallace JM, Robson PJ et al. (2009) Increased portion size leads to a sustained increase in energy intake over 4 d in normal-weight and overweight men and women. Br J Nutr 102, 470–477.
89.Rolls BJ, Roe LS & Meengs JS (2007) The effect of large portion sizes on energy intake is sustained for 11 days. Obesity (Silver Spring) 15, 1535–1543.
90.Raynor HA, Van Walleghen EL, Niemeier H et al. (2009) Do food provisions packaged in single-servings reduce energy intake at breakfast during a brief behavioral weight-loss intervention? J Am Diet Assoc 109, 1922–1925.
91.Raynor HA & Wing RR (2007) Package unit size and amount of food: do both influence intake? Obesity (Silver Spring) 15, 2311–2319.
92.Wansink B (1996) Can package size accelerate usage volume? J Mark 60, 1–14.
93.Pliner P & Mann N (2004) Influence of social norms and palatability on amount consumed and food choice. Appetite 42, 227–237.
94.Roth DA, Herman CP, Polivy J et al. (2001) Self-presentational conflict in social eating situations: a normative perspective. Appetite 36, 165–171.
95.Young LR & Nestle M (2002) The contribution of expanding portion sizes to the US obesity epidemic. Am J Public Health 92, 246–249.
96.Nielsen SJ & Popkin BM (2003) Patterns and trends in food portion sizes, 1977–1998. JAMA 289, 450–453.
97.Wansink B (2004) Environmental factors that increase the food intake and consumption volume of unknowing consumers. Annu Rev Nutr 24, 455–479.
98.Herman CP, Roth DA & Polivy J (2003) Effects of the presence of others on food intake: a normative interpretation. Psychol Bull 129, 873–886.
99.Vartanian LR, Herman CP & Wansink B (2008) Are we aware of the external factors that influence our food intake? Health Psychol 27, 533–538.
100.Rozin P, Kabnick K, Pete E et al. (2003) The ecology of eating: smaller portion sizes in France than in the United States help explain the French paradox. Psychol Sci 14, 450–454.
101.Rolls BJ, Rowe EA, Rolls ET et al. (1981) Variety in a meal enhances food intake in man. Physiol Behav 26, 215–221.
102.Kahn BE & Wansink B (2004) The influence of assortment structure on perceived variety and consumption quantities. J Consum Res 30, 519–533.
103.Brondel L, Romer M, Van Wymelbeke V et al. (2009) Variety enhances food intake in humans: role of sensory-specific satiety. Physiol Behav 97, 44–51.
104.Levitsky DA (2008) The control of food intake and the regulation of body weight in humans. In Appetite and Food Intake: Behavioral and Physiological Considerations, pp. 21–42 [RBS Harris and RD Mattes, editors]. Boca Raton, FL: CRC Press.
105.Smicklas-Wright H, Krebs-Smith S & Krebs-Smith J (1986) Variety in foods. In What is America Eating?, pp. 126–140. [National Research Council (US), Food and Nutrition Board, editor]. Washington, DC: National Academy Press.
106.Levitsky DA (2005) The non-regulation of food intake in humans: hope for reversing the epidemic of obesity. Physiol Behav 86, 623–632.
107.Levitsky DA (2008) Macronutrients and the control of body weight. In Nutrition in the Prevention and Treatment of Disease, 2nd ed., pp. 407–430 [A Coulston and CJ Boushey, editors]. London: Elsevier Academic Press.
108.Lissner L, Levitsky DA, Strupp BJ et al. (1987) Dietary fat and the regulation of energy intake in human subjects. Am J Clin Nutr 46, 886–892.
109.Kendall A, Levitsky DA, Strupp BJ et al. (1991) Weight loss on a low-fat diet: consequence of the imprecision of the control of food intake in humans. Am J Clin Nutr 53, 1124–1129.
110.Levitsky DA (2008) The control of food intake and the regulation of body weight in humans. In Appetite and Food Intake: Behavioral and Physiological Considerations, pp. 21–42 [RBS Harris and RD Mattes, editors]. Boca Raton, FL: CRC Press.
111.de Castro JM & Brewer EM (1992) The amount eaten in meals by humans is a power function of the number of people present. Physiol Behav 51, 121–125.
112.Dietz WH (2001) The obesity epidemic in young children – reduce television viewing and promote playing. BMJ 322, 313–314.
113.Harris JL, Bargh JA & Brownell KD (2009) Priming effects of television food advertising on eating behavior. Health Psychol 28, 404–413.
114.Halford JC, Gillespie J, Brown V et al. (2004) Effect of television advertisements for foods on food consumption in children. Appetite 42, 221–225.
115.Halford JC, Boyland EJ, Hughes G et al. (2007) Beyond-brand effect of television (TV) food advertisements/commercials on caloric intake and food choice of 5–7-year-old children. Appetite 49, 263–267.
116.Halford JC, Boyland EJ, Hughes GM et al. (2008) Beyond-brand effect of television food advertisements on food choice in children: the effects of weight status. Public Health Nutr 11, 897–904.
117.Bargh JA, Gollwitzer PM, Lee-Chai A et al. (2001) The automated will: nonconscious activation and pursuit of behavioral goals. J Pers Soc Psychol 81, 1014–1027.
118.Bargh JA & Ferguson MJ (2000) Beyond behaviorism: on the automaticity of higher mental processes. Psychol Bull 126, 925–945.
119.Ferguson MJ & Bargh JA (2004) How social perception can automatically influence behavior. Trends Cogn Sci 8, 33–39.
120.Cohen D & Farley TA (2008) Eating as an automatic behavior. Prev Chronic Dis 5, A23.
121.Cohen DA (2008) Neurophysiological pathways to obesity: below awareness and beyond individual control. Diabetes 57, 1768–1773.
122.Cohen DA (2008) Obesity and the built environment: changes in environmental cues cause energy imbalances. Int J Obes (Lond) 32, Suppl. 7, S137–S142.
123.Flegal KM & Troiano RP (2000) Changes in the distribution of body mass index of adults and children in the US population. Int J Obes Relat Metab Disord 24, 807–818.
124.Schachter S (1968) Obesity and eating. Internal and external cues differentially affect the eating behavior of obese and normal subjects. Science 161, 751–756.
125.Rodin J (1981) Current status of the internal–external hypothesis for obesity: what went wrong? Am Psychol 36, 361–372.
126.Olshansky SJ, Passaro DJ, Hershow RC et al. (2005) A potential decline in life expectancy in the United States in the 21st century. N Engl J Med 352, 1138–1145.
127.Levitsky DA, Halbmaier CA & Mrdjenovic G (2004) The freshman weight gain: a model for the study of the epidemic of obesity. Int J Obes Relat Metab Disord 28, 1435–1442.
128.Vella-Zarb RA & Elgar FJ (2009) The ‘freshman 5’: a meta-analysis of weight gain in the freshman year of college. J Am Coll Health 58, 161–166.
129.Levitsky DA, Garay J, Nausbaum M et al. (2006) Monitoring weight daily blocks the freshman weight gain: a model for combating the epidemic of obesity. Int J Obes (Lond) 30, 1003–1010.
130.Polivy J (1996) Psychological consequences of food restriction. J Am Diet Assoc 96, 589–592.
131.Wadden TA, Foster GD, Sarwer DB et al. (2004) Dieting and the development of eating disorders in obese women: results of a randomized controlled trial. Am J Clin Nutr 80, 560–568.
132.Stice E, Presnell K, Groesz L et al. (2005) Effects of a weight maintenance diet on bulimic symptoms in adolescent girls: an experimental test of the dietary restraint theory. Health Psychol 24, 402–412.
133.Presnell K, Stice E & Tristan J (2008) Experimental investigation of the effects of naturalistic dieting on bulimic symptoms: moderating effects of depressive symptoms. Appetite 50, 91–101.
134.Vogels N & Westerterp-Plantenga MS (2007) Successful long-term weight maintenance: a 2-year follow-up. Obesity (Silver Spring) 15, 1258–1266.
135.Wing RR & Phelan S (2005) Long-term weight loss maintenance. Am J Clin Nutr 82, 1 Suppl., 222S–225S.
136.Racette SB, Weiss EP, Schechtman KB et al. (2008) Influence of weekend lifestyle patterns on body weight. Obesity (Silver Spring) 16, 1826–1830.
137.Linde JA, Jeffery RW, French SA et al. (2005) Self-weighing in weight gain prevention and weight loss trials. Ann Behav Med 30, 210–216.
138.Sarkissian H, Chatterlee A, de Brigard F et al. (2010) Is belief in free will a cultural universal? Mind Lang 25, 346–358.
139.Dalgard OS & Lund Haheim L (1998) Psychosocial risk factors and mortality: a prospective study with special focus on social support, social participation, and locus of control in Norway. J Epidemiol Community Health 52, 476–481.
140.Sturmer T, Hasselbach P & Amelang M (2006) Personality, lifestyle, and risk of cardiovascular disease and cancer: follow-up of population based cohort. BMJ 332, 1359.
141.Rosengren A, Hawken S, Ounpuu S et al. (2004) Association of psychosocial risk factors with risk of acute myocardial infarction in 11 119 cases and 13 648 controls from 52 countries (the INTERHEART study): case–control study. Lancet 364, 953–962.
142.Burger JM (1984) Desire for control, locus of control, and proneness to depression. J Pers 52, 71–89.
143.Nunn GD (1988) Concurrent validity between the Nowicki–Strickland locus of control scale and the state-trait anxiety inventory for children. Educ Psychol Meas 48, 435–438.
144.Mackenbach JP, Simon JG, Looman CW et al. (2002) Self-assessed health and mortality: could psychosocial factors explain the association? Int J Epidemiol 31, 1162–1168.
145.Redman LM & Ravussin E (2011) Caloric restriction in humans: impact on physiological, psychological and behavioral outcomes. Antioxid Redox Signal 14, 275–285.
146.Canto C & Auwerx J (2009) Caloric restriction, SIRT1 and longevity. Trends Endocrinol Metab 20, 325–331.
147.Anderson RM & Weindruch R (2010) Metabolic reprogramming, caloric restriction and aging. Trends Endocrinol Metab 21, 134–141.
148.Brownell KD, Kersh R, Ludwig DS et al. (2010) Personal responsibility and obesity: a constructive approach to a controversial issue. Health Aff (Millwood) 29, 379–387.
149.Pfohl M, Luft D, Blomberg I et al. (1994) Long-term changes of body weight and cardiovascular risk factors after weight reduction with group therapy and dexfenfluramine. Int J Obes Relat Metab Disord 18, 391–395.
150.Gallo A (1997) First major drop in food product introductions in over 20 years. Food Rev 20, 33–35.