<P> Studies have hypothesized the continuance of disordered eating patterns may be epiphenomena of starvation . The results of the Minnesota Starvation Experiment showed normal controls exhibit many of the behavioral patterns of anorexia nervosa (AN) when subjected to starvation . This may be due to the numerous changes in the neuroendocrine system, which results in a self - perpetuating cycle . </P> <P> Another hypothesis is that anorexia nervosa is more likely to occur in populations in which obesity is more prevalent, and results from a sexually selected evolutionary drive to appear youthful in populations in which size becomes the primary indicator of age . </P> <P> Anorexia nervosa is more likely to occur in a person's pubertal years . Some explanatory hypotheses for the rising prevalence of eating disorders in adolescence are "increase of adipose tissue in girls, hormonal changes of puberty, societal expectations of increased independence and autonomy that are particularly difficult for anorexic adolescents to meet; (and) increased influence of the peer group and its values ." </P> <P> Early theories of the cause of anorexia linked it to childhood sexual abuse or dysfunctional families; evidence is conflicting, and well - designed research is needed . The fear of food is known as sitiophobia, cibophobia, or sitophobia and is part of the differential diagnosis . Other psychological causes of anorexia include low self - esteem, feeling like there is lack of control, depression, anxiety, and loneliness . </P>

Which of the following is a physiological change often associated with anorexia nervosa