Hedonic and incentive signals for body weight control

Here we review the emerging neurobiological understanding of the role of the brain’s reward system in the regulation of body weight in health and in disease. Common obesity is characterized by the over-consumption of palatable/rewarding foods, reflecting an imbalance in the relative importance of hedonic versus homeostatic signals. The popular ‘incentive salience theory’ of food reward recognises not only a hedonic/pleasure component (‘liking’) but also an incentive motivation component (‘wanting’ or ‘reward-seeking’). Central to the neurobiology of the reward mechanism is the mesoaccumbal dopamine system that confers incentive motivation not only for natural rewards such as food but also by artificial rewards (eg. addictive drugs). Indeed, this mesoaccumbal dopamine system receives and integrates information about the incentive (rewarding) value of foods with information about metabolic status. Problematic over-eating likely reflects a changing balance in the control exerted by hypothalamic versus reward circuits and/or it could reflect an allostatic shift in the hedonic set point for food reward. Certainly, for obesity to prevail, metabolic satiety signals such as leptin and insulin fail to regain control of appetitive brain networks, including those involved in food reward. On the other hand, metabolic control could reflect increased signalling by the stomach-derived orexigenic hormone, ghrelin. We have shown that ghrelin activates the mesoaccumbal dopamine system and that central ghrelin signalling is required for reward from both chemical drugs (eg alcohol) and also from palatable food. Future therapies for problematic over-eating and obesity may include drugs that interfere with incentive motivation, such as ghrelin antagonists

Implementing Achievable Benchmarks in Preventive Health: A Controlled Trial in Residency Education

Purpose: To evaluate the Preventive Health Achievable Benchmarks Curriculum, a multifaceted improvement intervention that included an objective, practice-based performance evaluation of internal medicine and pediatric residents’ delivery of preventive services. Method: The authors conducted a nonrandomized experiment of intervention versus control group residents with baseline and follow-up of performance audited for 2001-2004. All 130 internal medicine and 78 pediatric residents at two continuity clinics at the University of Alabama School of Medicine, Birmingham, participated. Performance of preventive care was assessed by structured chart review. The multifaceted feedback curriculum included individualized performance feedback, academic detailing by faculty, and collective didactic sessions. The main outcome was difference in receipt of preventive care for patients seen by intervention and control residents, comparing baseline and follow-up. Results: Charts were reviewed for 3,958 patients. Receipt of preventive care increased for patients of intervention residents, but not for patients of control residents. For the intervention group, significant increases occurred for five of six indicators in internal medicine: smoking screening, quit smoking advice, colon cancer screening, pneumonia vaccine, and lipid screening; and four of six in pediatrics: parental quit smoking advice, car seats, car restraints, and eye alignment (p \u3c .05 for all). For control residents, no consistent improvements were seen. There was greater improvement for intervention than for control residents for four of six indicators in internal medicine, and two of six in pediatrics. Conclusions: Using a multifaceted feedback curriculum, the authors taught residents about the care they provide and improved documented patient care

Development of Eating Patterns

As can be seen throughout this book, childhood and adolescent obesity is of great concern. Obesity during childhood and adolescence has been associated with physical, behavioral, and academic difficulties (Anderson & Butcher, 2006; Datar & Sturm, 2006). This chapter will discuss developmental patterns related to normative eating habits as well as eating patterns associated with problematic eating. Given that the behavioral correlates of eating habits and nutrition begin at birth, this chapter will cover eating patterns from infancy through adolescence. Because issues outside the family (such as the school environment and media) are also related to the development of eating patterns, they will be discussed briefly. The primary focus of this chapter, however, will be the influences of the family on the development of eating patterns