With food in mind

Abstract

According to the World Health Organization (WHO), overweight and obesity are defined as abnormal and/or excessive fat accumulation that may lead to life-long health complications, and it is typically quantified using the Body Mass Index (BMI). More specifically, a person with a BMI between 18.5 and 24.9 is considered to be healthy-weight, between 25 and 30 overweight, and over 30 obese. The obesity epidemic is globally recognized as a health crisis, threatening not only people's physical and mental health, but also governments' economies and health care systems. Obesity significantly increases the risk of severe health complications such as cancer, cardiovascular disease, type 2 diabetes, and mental health problems (e.g., depressive disorder, eating disorders; Caleyachetty et al., 2017;Danaei et al., 2009). According to a recent report of the World Health Organization (WHO), obesity has nearly tripled since 1975, with almost 2 billion adults with overweight and over 650 million with obesity (WHO, 2017). This amounts to 39% of the adult world population with overweight and 13% with obesity. Moreover, the same report estimated that 41 million children under the age of 5 years old suffer from overweight and/or obesity in 2016. The prevalence of overweight and obesity among adolescents (5-17 y. o.) has also risen dramatically from 4% in 1975 to over 18% in 2016. Therefore, in the year 2018, the estimated annual medical cost for the treatment and prevention of obesity was approximately $147 billion. Importantly, a crucial contributing factor to the obesity pandemic is the so-called obesogenic environment. The current Western environment is considered obesogenic, as people are surrounded by high caloric palatable foods, jobs require less physical effort, and not much time is left for sports and fitness (Hill et al., 2005;Morland & Evenson, 2009;Small, 2009). So, it is hard to stay or become lean in this obesogenic environment (Wadden et al., 2002). However, despite sharing the same environment, not everyone becomes CHAPTER 2 More complex than you might think: Neural representations of food reward value in obesity