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1. Introduction
Obesity is a chronic non-communicable disease with epidemic proportions worldwide. The World Health Organization (WHO) data confirms this statement: between 1975 and 2016 the obesity rates in the world tripled affecting about 39% of women and 39% of men aged 18 and over (WHO, 2017). Although the etiology of obesity involves a number of factors, including genetic, physiological, behavioral and environmental, the increase in these rates is mainly because of changes in the population’s feeding behavior, with an increase in the consumption of foods rich in sugars and fats (González-Muniesa et al., 2017; Romieu et al., 2017).
Cafeteria diets are animal models that attempt to mimic the poor eating habits that induce obesity in humans. For this purpose, highly palatable and caloric foods are offered to animals, which are mainly rich in sugars and saturated fats (Bortolin et al., 2018). The foods selected to be offered in a cafeteria diet usually have a very strong appeal for taste, causing in many cases induction of hyperphagia in animals, which is defined as caloric intake beyond energy needs (Macedo et al., 2016). Induction of hyperphagia with palatable diets has already been demonstrated with animals of adult age (Macedo et al., 2012; de Oliveira et al., 2014; Oliveira et al., 2015; Schimidt et al., 2018) or younger (Lazzarino et al., 2017; Teixeira et al., 2020), resulting in fat accumulation (Macedo et al., 2012; de Oliveira et al., 2014; Oliveira et al., 2015; Lazzarino et al., 2017; Schimidt et al., 2018; Teixeira et al., 2020). However, recent studies indicate that the cafeteria diet from birth to adulthood can be more harmful to the animals’ eating behavior (Guedine et al., 2018; Rocha-Gomes et al., 2019; Teixeira et al., 2020), as it increases the chances of compromising neurotransmitter systems (Wright et al., 2011; Rincel et al., 2016; Wolfrum and Peleg-Raibstein, 2019) as it is instituted during periods of brain vulnerability (Semple et al., 2013; Spencer, 2017).
The existing theory regarding the induction of hyperphagia through an animal cafeteria diet model is related to the dopaminergic receptors present in the nucleus accumbens (NAc). The constant stimulation of this...