het dopaminerge beloningssysteem

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1 het dopaminerge beloningssysteem 27/05/ mesolimbic DA system

2 lekker eten zorgt voor DA afgifte 27/05/ Bassareo and Di Chiara, 1997

3 palatable food and dopamine why would some people overeat and gain weight? hypersensitivity to reward DA response larger DA response time

4 palatable food and dopamine why would some people overeat and gain weight? DA response time

5 experiment Stoeckel et al., 2008 brain activation in response to different pictures overweight versus control presentation of visual stimuli fmri, brain regions associated with reward (VTA, NAc)

6 food reward and (over)weight higher activation in response to pictures of high-caloric food in overweight subjects. brain activation overweight control high cal low cal cars Adapted from Stoeckel et al., 2008

7 palatable food and dopamine positive relation between sensitivity to reward and BMI Sensitivity to reward BMI adapted from Davis et al., 2004

8 palatable food and dopamine why would some people overeat and gain weight? hyposensitivity to reward DA response lower DA response insensitive DA receptor self-medication to enhance DA activation and improve mood (Bowirrat & Oscar-Berman, 2005) time

9 chronic overeating leads to hyposensitivity 27/05/ [C-11]raclopride: radiotracer, binds to DA D2 receptors lower D2 binding in obese individuals Wang et al., 2001

10 chronic overeating leads to tolerance 27/05/ down-regulation of DA D2R caused by chronic overeating Wang et al., 2001

11 palatable food and dopamine negative relation between sensitivity to reward and BMI Adapted from Pagoto et al., 2006; Davis et al., 2004.

12 palatable food and reward hypersensitivity to reward hyposensitivity to reward?

13 obesity and reward for food hypersensitivity to reward hyposensitivity to reward normal to overweight subjects BMI: kg/m 2 obese subjects BMI 30 kg/m 2

14 obesity and reward for food Davis and Fox, 2008

15 obesity and reward for food reward dependence Davis and Fox, 2008

16 food addiction can be compared with drug dependence sensitization tolerance liking wanting

17 compulsief overeten 27/05/ overeten activeert het beloningssysteem in de hersenen R Simerly. Feeding signals and drugs meet in the midbrain. Nature Medicine - 12, (2006). Overeating may share neurobiological mechanisms with the addictive properties of drugs of abuse. - is overeten verslavend? comfort food, tolerantie (steeds meer nodig), rol van omgevingsfactoren en stress: alle kenmerken zijn aanwezig

18 compulsive overeating 27/05/ the problem usual treatment for addiction: - change the environment - stop intake of the drug (100%)

19 tolerantie 27/05/ tolerantie bij verslaving is het gevolg van conditionering door omgevingsfactoren

20 compulsive overeating 27/05/ the problem usual treatment for addiction: - change the environment - stop intake of the drug (100%) addicted to eating: - if you stop eating, you die..

21 voorkom overgewicht 27/05/ ) verminder het hedonisch overeten let op de invloed van de omgeving, stress, comfort food etc

22 regulatie van het lichaamsgewicht (set range) 27/05/ maximaal acceptabel niveau externe factoren: lichaams gewicht (vet) stress sociale factoren fysieke activiteit hedonics laagst acceptabel niveau leeftijd genen en homeostase bewaken de grenzen

23 regulatie van het lichaamsgewicht (set range) 27/05/ hioogst acceptabel niveau lichaams gewicht (vet) fysieke activiteit sport beweging (NEAT) laagst acceptabel niveau leeftijd genen en homeostase bewaken de grenzen

24 Obesity Trends* Among U.S. Adults BRFSS, 2010 (*BMI 30, or ~ 30 lbs. overweight for 5 4 person) No Data <10% 10% 14% 15% 19% 20% 24% 25% 29% 30% Source: Behavioral Risk Factor Surveillance System, CDC.

25 2008 estimates of leisure-time physical inactivity among adults aged 20 years 27/05/ Percent >

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27 verminderde fysieke activiteit 1950 vs 2000 vrijwel geen verschil in energie opname 27/05/ Nederland in 2002: minder dan 40% voldoet aan de minimum eis: 5x per week 30 min/dag matige inspanning

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30 voorkom overgewicht 27/05/ ) verminder het hedonisch overeten en 2) verhoog de fysieke activiteit life style interventie!

31 DPP Lifestyle: Weight Change + Weight Change (Kg) % in Risk Modest weight loss = Major health benefit Months in study Placebo Lifestyle 81

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33 NEAT 27/05/ percent of daily energy expenditure activity DIT BMR exercise non-exercise activity thermogenesis (NEAT) James A. Levine Science 1999

34 verkoop huishoudelijke apparaten en energie opname versus het % obesitas in de USA 27/05/ Levine, J. A. Am J Physiol Endocrinol Metab 286: E675-E

35 NEAT is belangrijk 27/05/ percent of daily energy expenditure Exercise NEAT DIT BMR JA Levine et al, Science 2005

36 lage activiteit 27/05/

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38 Environmental Change Policy Education 27/05/ steps -100 kcal/day Stop Weight Gain

39 pedometer / step counter 27/05/

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43 voorkom overgewicht 27/05/ ) verminder het hedonisch overeten en 2) verhoog de fysieke activiteit life style interventie!