Food cravings and food cue responding across the menstrual cycle in a non-eating disordered sample

Food craving, vitamin A, and menstrual disorders: A comprehensive study on university female students

BACKGROUND

Menstrual disorders, influenced by dietary habits like high fat intake and low fruit and vegetable consumption, are a global public health issue. This study assessed the prevalence of dysmenorrhea, premenstrual syndrome (PMS), and irregular menstrual cycle (IMC) among female university students in Bangladesh, focusing on food cravings and low vitamin A intake as risk factors.

METHODS

In this comprehensive study, data from randomly selected female university students were collected using a structured questionnaire. The associations were analyzed through chi-square tests and multivariable logistic regression, reported as adjusted odds ratios (AOR).

RESULTS

The most prevalent menstrual disorder was dysmenorrhea (68.3%) followed by PMS (33.8%), and IMC (24.3%). Food cravers for high-fat and sweet foods were likely to experience dysmenorrhea (AOR: 2.4, 95% CI: 1.5-3.9, P<0.001), suffer from PMS (AOR: 3.9, 95% CI: 2.3-6.6, P<0.001), and have IMC (AOR: 3.0, 95% CI: 1.6-5.3, P<0.001) vs. subjects who didn't. Subjects consuming vitamin A-rich plant foods had 40% (AOR: 0.6, 95% CI: 0.4-0.9, P < 0.01) and 60% (AOR: 0.4, 95% CI: 0.2-0.6, P<0.001) less likely suffering from dysmenorrhea and IMC vs. who didn't. Both underweight and overweight/obese subjects experienced more than 2-fold dysmenorrhea vs. normal-weight peers. The chance of IMC was nearly 3-fold among overweight/obese subjects. However, lower physical activity was associated with PMS and IMC whereas family history was associated with dysmenorrhea and PMS. Among the socio-demographic factors, maternal education, place of residence, and earlier menarche (≤12 years) were associated with dysmenorrhea while marital status was associated with IMC.

CONCLUSION

This study indicates that increasing the intake of vitamin A-rich plant foods and reducing high-fat, sweet foods can lower the risk of dysmenorrhea and IMC. Additionally, it highlights the need for regular exercise to mitigate the increased risk of PMS and IMC.

Resting energy metabolism and sweet taste preference during the menstrual cycle in healthy women

Differences in blood concentration of sex hormones in the follicular (FP) and luteal (LP) phases may influence energy metabolism in women. We compared fasting energy metabolism and sweet taste preference on a representative day of the FP and LP in twenty healthy women (25·3 (sd 5·1) years, BMI: 22·2 (sd 2·2) kg/m2) with regular self-reported menses and without the use of hormonal contraceptives. From the self-reported duration of the three prior menstrual cycles, the predicted FP and LP visits were scheduled for days 5-12 and 20-25 after menses, respectively. The order of the FP and LP visits was randomly assigned. On each visit, RMR and RQ by indirect calorimetry, sweet taste preference by the Monell two-series forced-choice tracking procedure, serum fibroblast growth factor 21 by a commercial ELISA (FGF21, a liver-derived protein with action in energy balance, fuel oxidation and sugar preference) and dietary food intake by a 24-h dietary recall were determined. Serum progesterone and oestradiol concentrations displayed the expected differences between phases. RMR was lower in the FP v. LP (5042 (sd 460) v. 5197 (sd 490) kJ/d, respectively; P = 0·04; Cohen effect size, d rm = 0·33), while RQ showed borderline significant higher values (0·84 (sd 0·05) v. 0·81 (sd 0·05), respectively; P = 0·07; d rm = 0·62). Also, in the FP v. LP, sweet taste preference was lower (12 (sd 8) v. 16 (sd 9) %; P = 0·04; d rm = 0·47) concomitant with higher serum FGF21 concentration (294 (sd 164) v. 197 (sd 104) pg/ml; P < 0·01; d rm = 0·66). The menstrual cycle is associated with changes in energy expenditure, sweet taste preference and oxidative fuel partitioning.

Neuroimaging and neuroendocrine insights into food cravings and appetite interventions in obesity

This article reviews the previous studies on the distinction between food cravings and appetite, and how they are regulated by hormones and reflected in brain activity. Based on existing research, food cravings are defined as individual preferences influenced by hormones and psychological factors, which differ from appetite, as they are not necessarily related to hunger or nutritional needs. The article also evaluates the neuroimaging findings about food cravings, and interventions to reduce food cravings, such as mindfulness training, alternative sweeteners, non-invasive brain stimulation techniques, cognitive-behavioral therapy, and imaginal retraining, and points out their advantages, disadvantages, and limitations. Furthermore, the article delves into the potential future directions in the field, emphasizing the need for a neuroendocrine perspective, considerations for associated psychiatric disorders, innovative clinical interventions, and emerging therapeutic frontiers in obesity management. The article outlines the neuro-endocrine basis of food cravings, including ghrelin, leptin, melanocortin, oxytocin, glucagon-like peptide-1, baclofen, and other hormones and their brain regions of action. The article argues that food cravings are an important target for obesity, and more research is needed to explore their complex characteristics and mechanisms, and how to effectively interact with their neuro-endocrine pathways. The article provides a new perspective and approach to the prevention and treatment of obesity.

Food preferences throughout the menstrual cycle - A computer-assisted neuro-endocrino-psychological investigation

BACKGROUND

As eating behavior changes in relation to the menstrual cycle and weight changes with menopausal transition, ovarian hormones appear to be involved in regulating eating behavior. However, observations are contradictory and are difficult to compare, due to methodological problems related to nutritional epidemiology. To better understand the relationship between ovarian steroid hormones and eating behavior, our study evaluates women's responses to visual food cues at different points in the menstrual cycle with their specific serum estrogen/progesterone levels and women's responses in the case of strong estrogen changes in the context of fertility treatments.

METHODS

We collected data from 129 women, 44 of whom received in vitro fertilization (IVF) at the Department of Reproductive Endocrinology, University Hospital Zurich. A total of 85 women with natural cycles were recruited at the University Hospital Zurich (n = 37) and at the Hannover Medical School (n = 48). Our observational study used 4 different measurement time points across the natural cycle and 2 measurement time points in women with supraphysiological estradiol levels during fertility treatments. Using a second cycle, we then tested our results for replication. At these predefined time points, women were shown pictures of 11 categories of food, with 4 items for each category and blood samples for measurement of hormone levels were taken. Food preferences registered at the time of the investigation were indicated on a visual analogue scale (0-100).

RESULTS

We did not find any statistically significant association between women's serum hormone levels and the rating of visually presented food, either during the menstrual cycle or during fertility treatments after controlling for multiple testing (all p > 0.005). Ratings for fruits, vegetables, and carbohydrates showed a significant linear decline throughout the first menstrual cycle (p < 0.01), which did not replicate in the second cycle (p > 0.05). In contrast, the ratings for sweets showed a significant linear decline in both cycles (both p < 0.01), with a mean rating of 54.2 and 48.8 in the menstrual phase of the first and second cycle, respectively, to a mean rating of 47.7 and 43.4 in the premenstrual phase of the first and second cycle, respectively. During fertility treatments, no food rating showed a significant change (all p > 0.05). Mood such as negative and positive affects did not influence ratings for visual food cues neither throughout the menstrual cycles nor during fertility treatment.

CONCLUSIONS

Serum levels of estradiol and progesterone do not correlate with food ratings in women, even when estradiol levels are above the physiological level of a natural menstrual cycle. Since, except for sweets, significant changes in food ratings in a first cycle did not replicate in a second menstrual cycle, significant findings from the literature based on animal or human studies focusing on a single-cycle have to be interpreted with caution.

Investigation of taste function and eating behavior in women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is the most common endocrine disorder in women of reproductive age that is associated with eating disorders and disordered eating. No data is available regarding taste function in women with PCOS. The aim of this study was to assess taste function and eating behavior in patients with PCOS compared to healthy women and investigate potential impact of oral contraceptive (OC) use on those. Forty-four patients with PCOS and 36 age and body-mass-index matched healthy controls were enrolled. Gustatory function was assessed by taste strips (sweet, sour, salty, bitter) and Food Cravings Questionnaire-Trait (FCQ-T), Night Eating Questionnaire (NEQ) and Three Factor Eating Questionnaire-R18 (TFEQ-R18) were applied. All measurements were repeated in patients after receiving an OC along with general lifestyle advice for 3 months. At baseline, PCOS group had lower total taste strip test (TST) scores compared to controls (11.7 ± 2.2 vs. 13.1 ± 1.4; p = 0.001). Subgroup analysis showed lower sour and salty taste scores in PCOS group (2.4 ± 0.9 vs. 2.9 ± 0.7; p = 0.004; and 2.6 ± 1 vs. 3.1 ± 0.7; p = 0.01 respectively). Sweet and bitter taste scores were similar. No difference was determined in eating behavior. Linear regression analysis revealed that hyperandrogenism was significant predictor for total TST score (R² = 0.22, p < 0.001). Higher free androgen index (FAI) was associated with lower total TST score (p = 0.01). Total TST score, TFEQ-R18 and NEQ scores remained unaltered after treatment in the PCOS group whereas FCQ-T scores showed significant reduction (p = 0.02), mainly due to a decrease in lack of control subscale (p = 0.01). Our results suggest that taste perception is reduced in PCOS, and short-term OC use does not alter taste functions in the syndrome.

Support for a two-dimensional model of food craving using self-report questionnaire and cue-reactivity methodologies

OBJECTIVE

Evidence supports the transdiagnostic importance of food cravings across the spectrum of disordered eating behaviors. The ambivalence model of craving (AMC), originally applied to substance use craving, highlights the need to consider not just the motivational state of "approach," but also that of "avoidance." The aims of this project were to (a) extend the existing literature by providing additional psychometric support for the food approach and avoidance questionnaire (FAAQ), (b) extend research supporting the validity of applying the AMC to disordered eating by incorporating a cue-reactivity paradigm, and (c) examine the unique contributions of the FAAQ and in-the-moment cue-elicited craving to the prediction of disordered eating.

METHOD

Participants (N = 223; 52.0% female, age M = 20.51 years) were recruited from a large southeastern university. Participants completed a food cue-reactivity paradigm and measures of food craving and disordered eating in a lab setting.

RESULTS

The factor structure and construct validity of the FAAQ was supported and both general states of food craving (i.e., FAAQ) and cue-elicited food craving were incrementally associated with the spectrum of disordered eating behaviors. As anticipated, both FAAQ and in-the-moment cue-elicited approach were primarily associated with overeating behaviors, whereas FAAQ and cue-elicited avoidance were primarily associated with restrictive eating behaviors.

DISCUSSION

Findings highlight the importance of including an avoidance dimension of food craving and have important implications for disordered eating prevention and intervention work.

Visual stimulation with food pictures in the regulation of hunger hormones and nutrient deposition, a potential contributor to the obesity crisis

Food cues affect hunger and nutritional choices. Omnipresent stimulation with palatable food contributes to the epidemics of obesity. The objective of the study was to investigate the impact of food cues on appetite-related hormones and to assess the functionality of the secreted hormones on macronutrient uptake in healthy subjects. Additionally, we aimed at verifying differences in the response of total and active ghrelin to stimulation with food pictures and to a meal followed by the stimulation. We were also interested in the identification of factors contributing to response to food cues. We recruited healthy, non-obese participants for two independent cross-over studies. During the first study, the subjects were presented random non-food pictures on the first day and pictures of foods on the second day of the study. Throughout the second study, following the picture session, the participants were additionally asked to drink a milkshake. Concentrations of blood glucose, triglycerides and hunger-related hormones were measured. The results showed that concentrations of several hormones measured in the blood are interdependent. In the case of ghrelin and gastric inhibitory peptide (GIP) as well as ghrelin and glucagon-like peptide-1 (GLP-1), this co-occurrence relies on the visual cues. Regulation of total ghrelin concentration following food stimulation is highly individual and responders showed upregulated total ghrelin, while the concentration of active ghrelin decreases following a meal. Protein content and colour intensity of food pictures reversely correlated with participants’ rating of the pictures. We conclude that observation of food pictures influences the concentration of several appetite-related hormones. The close link of visual clues to physiological responses is likely of clinical relevance. Additionally, the protein content of displayed foods and green colour intensity in pictures may serve as a predictor of subjective attractiveness of the presented meal.

Twenty Years of the Food Cravings Questionnaires: a Comprehensive Review

Purpose of Review

The Food Cravings Questionnaires (FCQs; Cepeda-Benito, Gleaves, Williams, & Erath, 2000) are among the most widely used instruments for measuring food cravings. In addition to the Food Cravings Questionnaire–Trait (FCQ–T) and the Food Cravings Questionnaire–State (FCQ–S), several modified versions have been developed as well. For their 20th anniversary, this article provides a comprehensive description of the FCQs and reviews studies on their psychometric properties and correlates.

Recent Findings

The FCQs and their modified versions have excellent internal reliability. Expectedly, the FCQ–T (and its derivatives) has higher retest-reliability than the FCQ–S as the FCQ–S is sensitive to situational changes such as food deprivation and food intake. However, while the FCQ–T is largely unaffected by such momentary states, it is also sensitive to change during weight-loss treatments and other interventions. Factor structure of the FCQ–T and FCQ–S has only partially been replicated. Construct validity of the FCQs is supported by experimental and longitudinal studies that measured food craving and food consumption in the laboratory and with ecological momentary assessment.

Summary

Numerous studies support reliability and validity of the FCQs and their modified versions, yet findings about their factor structures are inconsistent. Thus, using total scores or the short versions of the FCQs may be preferable.

Cue-induced craving and symptoms of online-buying-shopping disorder interfere with performance on the Iowa Gambling Task modified with online-shopping cues

BACKGROUND AND AIMS

Subjects with buying-shopping disorder (BSD) continue to buy offline as well as online despite negative consequences. Previous studies indicate that subjects with BSD show cue-reactivity and craving when exposed to shopping cues and have problems in long-term advantageous decision-making. The current study aimed at investigating the effect of online-shopping cues on decision-making, and whether addiction-relevant concepts such as cue-reactivity/craving and the symptom severity of BSD are related to decision-making.

METHODS

A non-clinical sample of 57 participants played a version of the modified Iowa Gambling Task (IGT), with online-shopping-related pictures shown either on the advantageous decks or on the disadvantageous decks (with control pictures on the opposing ones). Symptom severity of online-BSD and the craving to buy were assessed using questionnaires. In addition, the online-shopping pictures were rated concerning arousal, valence, and urge to buy.

RESULTS

The participants who played the IGT with the online-shopping pictures displayed on the disadvantageous decks performed significantly poorer than the other group with online-shopping pictures on the advantageous decks. The between-group differences were moderated by craving reactions and the symptom severity of online-BSD: When online-shopping pictures were displayed on the disadvantageous decks, this only interfered with IGT performance in participants who had high craving reactions towards shopping cues and/or high symptom severity of online-BSD.

CONCLUSION

Results indicate that exposure to online-shopping cues interferes with advantageous decision-making, especially in individuals with craving reactions and high symptoms of online-BSD. Results contribute to the question of why some people continue to buy despite negative consequences.

Got chocolate? Bilateral prefrontal cortex stimulation augments chocolate consumption

BACKGROUND

Understanding the mechanisms behind exerting self-control may reveal why health behaviors are resistant to change. Activity in the right inferior frontal gyrus (rIFG) plays a role in self-control processes and may be modulated using transcranial direct current stimulation (tDCS).

OBJECTIVE

In this early phase behavioral research study, we investigated whether anodal stimulation over the rIFG with cathodal stimulation over the left IFG (versus sham) reduced chocolate consumption.

METHODS

Twenty-three healthy females (ages 18-35) completed two tDCS sessions (2.0 mA vs. sham; order counterbalanced) in a within-subject, double-blind, randomized design with a 4-week washout. Participants were self-reported "chocolate cravers" and restrained eaters. Self-report assessments on disinhibited eating were completed at intake. Delay discounting and inhibitory control were assessed at the remaining visits. During stimulation, participants completed an inhibitory control training task (chocolate go/no-go task) and were randomized to the chocolate no-go condition (inhibit all responses to chocolate cues) or the control condition (inhibit responses to chocolate cues on half the trials). Following stimulation, participants completed a 15-min chocolate "taste test" with chocolate rating forms. Afterwards, staff measured the remaining chocolate to determine total consumption.

RESULTS

Contrary to our hypotheses, active tDCS significantly increased chocolate consumption vs. sham (mean = 43.2 vs. 32.2, p=0.005) in both task conditions, but had no effect on chocolate ratings (ps > 0.05). Higher delay discounting and self-reported disinhibited eating predicted greater consumption (ps < 0.05).

CONCLUSIONS

The results suggest widespread activation of the prefrontal cortex may reduce the ability to resist chocolate. Our data highlights important methodological considerations for conducting tDCS studies to target health behaviors.

Effects of Estrogens on Central Nervous System Neurotransmission: Implications for Sex Differences in Mental Disorders

Nearly one of every five US individuals aged 12 years old or older lives with certain types of mental disorders. Men are more likely to use various types of substances, while women tend to be more susceptible to mood disorders, addiction, and eating disorders, all of which are risks associated with suicidal attempts. Fundamental sex differences exist in multiple aspects of the functions and activities of neurotransmitter-mediated neural circuits in the central nervous system (CNS). Dysregulation of these neural circuits leads to various types of mental disorders. The potential mechanisms of sex differences in the CNS neural circuitry regulating mood, reward, and motivation are only beginning to be understood, although they have been largely attributed to the effects of sex hormones on CNS neurotransmission pathways. Understanding this topic is important for developing prevention and treatment of mental disorders that should be tailored differently for men and women. Studies using animal models have provided important insights into pathogenesis, mechanisms, and new therapeutic approaches of human diseases, but some concerns remain to be addressed. The purpose of this chapter is to integrate human and animal studies involving the effects of the sex hormones, estrogens, on CNS neurotransmission, reward processing, and associated mental disorders. We provide an overview of existing evidence for the physiological, behavioral, cellular, and molecular actions of estrogens in the context of controlling neurotransmission in the CNS circuits regulating mood, reward, and motivation and discuss related pathology that leads to mental disorders.

O Uso de Biomarcadores em Pesquisas de Marketing

Resumo A aproximação do marketing com a neurociência tem gerado expectativa tanto na academia quanto no mercado, em especial na última década. Apesar do interesse e das promessas de resultados, lacunas de conhecimento neurobiológico são percebidas acerca de formas de coleta e análise de dados. Este estudo apresenta e compara algumas ferramentas neurocientíficas que são fundamentadas em respostas não cognitivas do cérebro humano. A coleta e a análise de biomarcadores, como hormônios e níveis de atividade elétrica muscular, podem ser utilizadas em pesquisas de comportamento humano relacionadas ao consumo ou em outras interações com ações de marketing. A metodologia de aplicação dessas ferramentas, medidas resultantes e possíveis interpretações de comportamento também são discutidas, com ênfase em futura agenda de pesquisa.

Cross-sectional and longitudinal associations between different exercise types and food cravings in free-living healthy young adults

INTRODUCTION

An increase in energy intake due to alterations in hedonic appetite sensations may, at least in part, contribute to lower-than-expected weight loss in exercise interventions. The aim of this study was to examine cross-sectional and longitudinal associations between habitual exercise participation and food cravings in free-living young adults.

METHODS

A total of 417 adults (49% male, 28 ± 4 years) reported frequency and duration of walking, aerobic exercise, resistance exercise and other exercise at baseline and every 3 months over a 12-month period. Food cravings were assessed via the Control of Eating Questionnaire at baseline and 12-month follow-up.

RESULTS

Cross-sectional analyses revealed more frequent cravings for chocolate and a greater difficulty to resist food cravings in women compared to men (p < 0.01). Only with resistance exercise significant sex by exercise interaction effects were observed with favorable responses in men but not in women. Significant main effects were shown for walking and aerobic exercise with exercisers reporting more frequent food cravings for chocolate and fruits and greater difficulty to resist eating compared to non-exercisers (p < 0.05). Longitudinal analyses revealed significant interaction effects for other exercise (p < 0.05) with favorable results in men but not women. Furthermore, significant main effects were observed for aerobic exercise, resistance exercise and total exercise with an increase in exercise being associated with a reduced difficulty to resist food cravings (p < 0.05).

DISCUSSION

The association between exercise participation and hedonic appetite sensations varies by exercise type and sex. Even though exercise was associated with more frequent and greater difficulty to food cravings in the cross-sectional analyses, which may be attributed to greater energy demands, longitudinal results indicate beneficial effects of increased exercise on appetite control, particularly in men.

Menstrual Cycle and Hormonal Contraceptive-Dependent Changes in Intrinsic Connectivity of Resting-State Brain Networks Correspond to Behavioral Changes Due to Hormonal Status

Menstrual cycle-dependent changes have been reported for a variety of functions, including cognition, attention, emotion, inhibition, and perception. For several of these functions, an effect of hormonal contraceptives has also been discussed. Cognitive, attentional, emotional, inhibitory, and perceptual functions have been linked to distinct intrinsic connectivity networks during the resting state. However, changes in resting-state connectivity across the menstrual cycle phase and due to hormonal contraceptive use have only been investigated in two selected networks and without controlling for the type of hormonal contraceptives. In the present study, we demonstrate menstrual cycle and hormonal contraceptive-dependent changes in several intrinsic connectivity networks, including networks that have been related to emotion processing, olfaction, audition, vision, coordination, and two lateralized frontoparietal networks related to a variety of cognitive functions. These changes parallel behavioral changes in the functions associated with these networks. Changes in connectivity and changes in behavior occur during the same cycle phases. Furthermore, hormonal contraceptive-dependent effects were observed in the same networks and same target sites as menstrual cycle-related changes and were dependent on the androgenicity of the progestin component contained in the hormonal contraceptive.

Putting the brakes on the "drive to eat": Pilot effects of naltrexone and reward-based eating on food cravings among obese women

PURPOSE

Obese individuals vary in their experience of food cravings and tendency to engage in reward-driven eating, both of which can be modulated by the neural reward system rather than physiological hunger. We examined two predictions in a sample of obese women: (1) whether opioidergic blockade reduced food-craving intensity, and (2) whether opioidergic blockade reduced an association between food-craving intensity and reward-driven eating, which is a trait-like index of three factors (lack of control over eating, lack of satiation, preoccupation with food).

METHODS

Forty-four obese, pre-menopausal women completed the Reward-Based Eating Drive (RED) scale at study start and daily food-craving intensity on 5 days on which they ingested either a pill-placebo (2 days), a 25 mg naltrexone dose (1 day), or a standard 50mg naltrexone dose (2 days).

RESULTS

Craving intensity was similar under naltrexone and placebo doses. The association between food-craving intensity and reward-driven eating significantly differed between placebo and 50mg naltrexone doses. Reward-driven eating and craving intensity were significantly positively associated under both placebo doses. As predicted, opioidergic blockade (for both doses 25mg and 50mg naltrexone) reduced the positive association between reward-driven eating and craving intensity to non-significance.

CONCLUSIONS

Opioidergic blockade did not reduce craving intensity; however, blockade reduced an association between trait-like reward-driven eating and daily food-craving intensity, and may help identify an important endophenotype within obesity.

Pathological Buying Online as a Specific Form of Internet Addiction: A Model-Based Experimental Investigation

The study aimed to investigate different factors of vulnerability for pathological buying in the online context and to determine whether online pathological buying has parallels to a specific Internet addiction. According to a model of specific Internet addiction by Brand and colleagues, potential vulnerability factors may consist of a predisposing excitability from shopping and as mediating variable, specific Internet use expectancies. Additionally, in line with models on addiction behavior, cue-induced craving should also constitute an important factor for online pathological buying. The theoretical model was tested in this study by investigating 240 female participants with a cue-reactivity paradigm, which was composed of online shopping pictures, to assess excitability from shopping. Craving (before and after the cue-reactivity paradigm) and online shopping expectancies were measured. The tendency for pathological buying and online pathological buying were screened with the Compulsive Buying Scale (CBS) and the Short Internet Addiction Test modified for shopping (s-IATshopping). The results demonstrated that the relationship between individual's excitability from shopping and online pathological buying tendency was partially mediated by specific Internet use expectancies for online shopping (model's R² = .742, p < .001). Furthermore, craving and online pathological buying tendencies were correlated (r = .556, p < .001), and an increase in craving after the cue presentation was observed solely in individuals scoring high for online pathological buying (t(28) = 2.98, p < .01, d = 0.44). Both screening instruments were correlated (r = .517, p < .001), and diagnostic concordances as well as divergences were indicated by applying the proposed cut-off criteria. In line with the model for specific Internet addiction, the study identified potential vulnerability factors for online pathological buying and suggests potential parallels. The presence of craving in individuals with a propensity for online pathological buying emphasizes that this behavior merits potential consideration within the non-substance/behavioral addictions.

Sex differences in the physiology of eating

Hypothalamic-pituitary-gonadal (HPG) axis function fundamentally affects the physiology of eating. We review sex differences in the physiological and pathophysiological controls of amounts eaten in rats, mice, monkeys, and humans. These controls result from interactions among genetic effects, organizational effects of reproductive hormones (i.e., permanent early developmental effects), and activational effects of these hormones (i.e., effects dependent on hormone levels). Male-female sex differences in the physiology of eating involve both organizational and activational effects of androgens and estrogens. An activational effect of estrogens decreases eating 1) during the periovulatory period of the ovarian cycle in rats, mice, monkeys, and women and 2) tonically between puberty and reproductive senescence or ovariectomy in rats and monkeys, sometimes in mice, and possibly in women. Estrogens acting on estrogen receptor-α (ERα) in the caudal medial nucleus of the solitary tract appear to mediate these effects in rats. Androgens, prolactin, and other reproductive hormones also affect eating in rats. Sex differences in eating are mediated by alterations in orosensory capacity and hedonics, gastric mechanoreception, ghrelin, CCK, glucagon-like peptide-1 (GLP-1), glucagon, insulin, amylin, apolipoprotein A-IV, fatty-acid oxidation, and leptin. The control of eating by central neurochemical signaling via serotonin, MSH, neuropeptide Y, Agouti-related peptide (AgRP), melanin-concentrating hormone, and dopamine is modulated by HPG function. Finally, sex differences in the physiology of eating may contribute to human obesity, anorexia nervosa, and binge eating. The variety and physiological importance of what has been learned so far warrant intensifying basic, translational, and clinical research on sex differences in eating.