In other cases, lower to medium BMI values were also reported, partly related to restrictive eating behaviors. Nutritional status is perceived as a relevant factor when administering HT and seems to be influenced by this therapy. Transgender health is a new area in the field of nutrition, given the unique gender experience of this population, which may not follow the standard dietary and nutritional recommendations, as well as the specific nutritional concerns related to HT. During the mid-luteal phase, it is likely that high levels of progesterone serve to antagonize the typical protective action of elevated estradiol, and in the premenstrual phase, low progesterone likely permits the behavioral effects of low estradiol to be expressed. Genetic activation is reflected at the top half of each figure and refers to the developmental emergence of genetic influences (via heritabilty estimates) on eating pathology in boys, i.e., during adrenarche, or girls, i.e., during gonadarche. Pharmacological manipulation of androgens in women with BN provides further evidence of positive testosterone-pathological eating associations. In their review, the lack of consistency in measures used to assess ED outcomes made for more difficult comparisons across the screened studies . When these hormones fluctuate during menstrual cycles, due to contraception, or for other reasons, the body’s signals can become dysregulated, potentially lending to the development of eating disorders. Lastly, testosterone, a hormone that regulates sex drive and tissue development, has been found to stimulate hunger and food intake. This chemical can have significant effects on food intake when in the presence of estradiol in the body. Those who experience eating disorders often experience altered eating habits, obsessions and negative associations with food and eating, and an intense fixation on weight, size, or musculature. An eating disorder is a serious mental health condition characterized by intense, persistent changes in one’s relationship with food, eating, and/or body image. The same endocrinopathies seen in females with AN can also occur in males. In summary, AN is not only a disease in females but should also be suspected in males with multiple endocrine dysfunction. Biochemical parameters such as bone turnover markers, total and free testosterone, prolactin, LH, FSH, ACTH, IGF-1, GH, and total and free T3 levels were not universally assessed in all 4 patients during their admission and would have possibly provided an opportunity for further analysis and conclusions. Low levels of testosterone and dehydroepiandrosterone may contribute to low bone mass during puberty. Additionally, the loss of body fat leads to decreased aromatization of androgens to estrogens. A decrease in normal body weight by 10 to 15% can cause amenorrhea (17). The hypothalamic-pituitary-gonadal axis has welldescribed alterations in females with AN, which is similar to males with AN, as in our cohort. Although these effects (e.g., moderators of ovarian hormone effects) have been explored in several female studies, researchers have yet to explore sociocultural/psychological moderators of biological risk factors for eating pathology in boys/men. Furthermore, it is expected that sociocultural and psychological factors intersect with biological factors to impact individual and sex differences in risk for eating pathology. Consequently, between-sex and within-sex differences in risk for eating pathology seem to arise from a combination of, and interplay between, genetic, hormonal, and brain-driven processes. In contrast, none of the ten participants screened positive for disordered eating using the EAT-26 tool in the Linsenmeyer et al. case study . The participant also showed compensatory food behavior such as bingeing and purging via vomiting, as well as practicing a diet with restricted energy intake, excessive use of laxatives, and the usage of weight loss supplements . Linsenmeyer et al. used the EAT-26 and ecSI-2 tools to assess the degree of eating competence and the risk of ED . Wierckx et al. reported a significant increase in the total body fat in the participating TW . Conversely, significant changes were observed in the fat mass in the Berra et al. study . In fact, a female bias is evidenced by previous diagnostic criteria, which include amenorrhea but not low testosterone or decreased libido. Increased awareness of AN in males is vital, as its prevalence is likely underestimated and appropriate diagnosis and treatment can ameliorate the metabolic dysfunction in a majority of cases. This small case series highlights the importance of AN as a potential cause of multiple endocrinopathies in males. Most of the clinical effects from these endocrinopathies resolved with improved caloric intake and nutrition, although symptoms of hypogonadism persisted. Cortisol resistance is suspected based on elevated cortisol levels with normal adrenocorticotropic hormone levels. These men had an average BMI of 13.85 kg/m2 (range, 12 to 18 kg/m2), weight loss of 87.75 pounds (range, 35 to 141 pounds), temperature of 35.2°C (range, 33.9 to 36.4°C), heart rate of 39.75 beats per minute (range, 30 to 60 beats per minute), and blood pressure 87/57 mm Hg (range, 74/48 to 94/68 mm Hg). Following involvement of the endocrinology team, concern about a likely eating disorder as the etiology of his symptoms was discussed. An upper endoscopy was performed to further evaluate weight loss and persistent nausea and vomiting, which revealed chronic gastritis and Helicobacter pylori, without evidence of malabsorption. Article abstracts were screened for relevance, and studies were included if the study design and findings addressed some biological aspect of sex differences in the etiology of pathological eating symptoms or related behavior (e.g., hedonic eating). Notably, sex-specific biological factors/effects can contribute to differentiation of the sexes and may therefore inform sex differences in eating pathology. Because of the sex difference in eating disorder prevalence, a large proportion of biological research on eating pathology in humans has either exclusively focused on females or used samples that are predominantly comprised of females. This narrative review summarizes evidence of biological factors related to sex differences in eating pathology.
