Possible factors for altered energy balance across the menstrual cycle: a closer look at the severity of PMS, reward driven behaviors and leptin variations

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.

Association between Dietary Habits and Severity of Symptoms in Premenstrual Syndrome

BACKGROUND

Premenstrual syndrome (PMS) is a set of physical, psychological, and emotional symptoms that occur during the luteal phase of the menstrual cycle. The etiopathogenesis of this condition is not fully understood, and several studies suggest a possible role of environmental factors, such as diet. The aim of this work was to investigate the relationship between dietary habits and the occurrence and severity of PMS.

METHODS AND RESULTS

Forty-seven women were enrolled in the study. Participants were asked to complete the Daily Record of Severity of Problems (DRSP) to diagnose PMS and to complete a three-day food record during the perimenstrual phase. Thirty women completed the study (16 with PMS and 14 controls). An analysis of the food diaries revealed no differences between the women with PMS and the control subjects in terms of total energy intake (1649 vs. 1570 kcal/day), diet composition, and the consumption of macro- or micronutrients, except for copper, whose consumption was higher in women with PMS than in the control subjects (1.27 ± 0.51 vs. 0.94 ± 0.49 mg/d, p < 0.05).

CONCLUSIONS

The data presented here are very preliminary, and only a significant difference in copper intake was found when comparing women with PMS and controls. Larger studies are needed to better define how diet may contribute to the exacerbation of the psychological and somatic symptoms associated with PMS and whether PMS itself may influence macro- or micronutrient intake by changing dietary habits.

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.

Attentional bias towards appealing and disgusting food cues varies with the menstrual cycle

Ovarian hormonal changes along the female menstrual cycle are believed to adapt women to the external environment through various adaptive strategies, including modulating appetite and eating behavior. We aimed to compare food-associated behavioral responses between two distinct menstrual phases (late follicular vs. mid-luteal) and investigate the underlying neural mechanism. Attentional bias towards visual food cues was repeatedly measured in 29 healthy young women during these two menstrual phases in a counterbalanced manner. Combining an emotional dot-probe task with frequency-tagged electroencephalography (EEG), we confirmed that the menstrual cycle modulated healthy women's attentional bias towards appealing and disgusting food cues. Women in the mid-luteal phase showed more avoidance of disgusting food cues, as reflected by a significantly longer response time. Steady-state visual evoked potential (SSVEP) results indicated that they exhibited a trend of transiently enhanced attentional bias towards appealing food cues and another trend of speeded attentional withdrawal from disgusting food cues during the mid-luteal phase relative to the late follicular phase, albeit non-significant after correction for multiple testing. Moreover, a significantly larger P3 amplitude was evoked by probes following the presentation of disgusting food cues in the mid-luteal phase than the late follicular phase. These findings indicate divergent attentional deployments on emotional food cues across menstrual phases and suggest the mid-luteal phase as a relatively sensitive stage in the menstrual cycle for women to regulate their appetite and eating behavior.

The Specificities of Elite Female Athletes: A Multidisciplinary Approach

Female athletes have garnered considerable attention in the last few years as more and more women participate in sports events. However, despite the well-known repercussions of female sex hormones, few studies have investigated the specificities of elite female athletes. In this review, we present the current but still limited data on how normal menstrual phases, altered menstrual phases, and hormonal contraception affect both physical and cognitive performances in these elite athletes. To examine the implicated mechanisms, as well as the potential performances and health risks in this population, we then take a broader multidisciplinary approach and report on the causal/reciprocal relationships between hormonal status and mental and physical health in young (18-40 years) healthy females, both trained and untrained. We thus cover the research on both physiological and psychological variables, as well as on the Athlete Biological Passport used for anti-doping purposes. We consider the fairly frequent discrepancies and summarize the current knowledge in this new field of interest. Last, we conclude with some practical guidelines for eliciting improvements in physical and cognitive performance while minimizing the health risks for female athletes.

Exercise for Weight Loss: Further Evaluating Energy Compensation with Exercise

Purpose

This study assessed how individuals compensate for energy expended during a 12-wk aerobic exercise intervention, elucidating potential mechanisms and the role exercise dose plays in the compensatory response.

Participants and Design

Three-arm, randomized controlled trial among sedentary adults age 18 to 40 yr, body mass index of 25 to 35. Groups included six exercise sessions per week, two sessions per week, and sedentary control.

Methods

Rate of exercise energy expenditure was calculated from a graded exercise test averaged across five heart rate zones. Energy compensation was calculated as the difference between expected weight loss (based on exercise energy expenditure) and changes in fat and fat-free mass (DXA). Resting energy expenditure was assessed via indirect calorimetry and concentrations of acylated ghrelin, leptin, insulin, and Glucagon-like peptide 1 (GLP-1) were assessed fasting and postprandial (six timepoints over 2 h).

Results

The 6-d·wk⁻¹ group expended more energy (2753.5 kcal) and exercised longer (320.5 min) per week than the 2-d·wk⁻¹ group (1490.7 kcal, 1888.8 min, P < 0.05), resulting in greater fat loss compared with the 2-d or control groups (P < 0.05). Exercise groups did not differ in the % or total kcal compensated. Greater decreases in area under the curve (AUC) for acylated ghrelin predicted greater fat loss, regardless of group, energy expended per week, exercise duration, or exercise intensity. Changes in leptin AUC was the only independent predictor for energy compensation, with a greater decrease in leptin AUC predicting less energy compensation. Exercise frequency, energy expended, duration, or intensity did not influence energy compensation.

Conclusions

Leptin is an important factor in successful weight loss through exercise, with greater postprandial decreases promoting less compensation. Greater amounts of exercise do not influence the compensatory response to an exercise-induced energy deficit.

Why young women gain weight: A narrative review of influencing factors and possible solutions

Significant weight gain occurs in women during young adulthood, which increases risk of diseases such as diabetes, cardiovascular disease, and many cancers. This review aims to inform future individually targeted weight gain prevention programmes and summarizes possible targets: key life events, mediators that influence energy intake and physical activity levels, and moderators that could identify groups of women at greatest risk. Life events affecting weight include pregnancy and motherhood, smoking cessation, marriage and cohabiting, attending university, and possibly bereavement. Research has identified successful methods for preventing weight gain associated with pregnancy and motherhood, which could now be used in practice, but evidence is inconclusive for preventing weight gain around other life events. Weight gain is mediated by lack of knowledge and skills around food and nutrition, depression, anxiety, stress, satiety, neural responses, and possibly sleep patterns and premenstrual cravings. A paucity of research exists into altering these to limit weight gain. Moderators include socioeconomic status, genetics, personality traits, and eating styles. More research is required to identify at-risk females and engage them in weight gain prevention. There is a need to address evidence gaps highlighted and implement what is currently known to develop effective strategies to limit weight gain in young women.

Assessing the influence of fasted and postprandial states on day-to-day variability of appetite and food preferences

INTRODUCTION

Ratings of subjective appetite and food hedonics provide valuable information about energy and macronutrient intake. Ensuring reproducibility of measures of subjective appetite, and food liking and wanting is essential for accurate understanding about their implementation in intervention studies.

METHODS

Nineteen participants participated in two separate 10-h test days consisting of 6 test meals. Subjective appetite was measured in the fasted state and periodically across the test day in a postprandial state. Liking and wanting were measured using the Leeds Food Preferences Questionnaire (LFPQ) immediately before and after breakfast, immediately before the second meal, and at the end of the test day.

RESULTS

Reproducibility of appetite scores was similar to those previously reported in males, however females tended to have consistently higher CVs, wider CRs and wider 95% CIs. Variability in food hedonics was of a similar magnitude to subjective appetite with CVs for fasting explicit liking and wanting between 15.3 and 33.4%, correlations for both implicit and explicit liking and wanting between 0.18 and 0.87 and CRs indicating 95% of between-day changes for any given individual should fall within ±43.4 mm of the mean change. Averages of food hedonics during the test day reduced CVs, improved correlations and reduced CRs. Despite no mean change in preceding energy and nutrient intake, individual changes in prior energy and macronutrient intake appeared to influence individual between-day changes in appetite and food hedonics, and appetite and food hedonics were intricately linked.

CONCLUSIONS

Larger subject numbers may be required for appetite studies with female participants due to greater appetite variability. The LFPQ as a tool for measuring implicit and explicit liking and wanting is sufficiently reproducible and improved by averaging multiple measures across a day.

Higher energy intake at dinner decreases parasympathetic activity during nighttime sleep in menstruating women: A randomized controlled trial

BACKGROUND

Previous studies have found more frequent increases in dietary intake and nonrestorative nocturnal sleep during the luteal phase than in the follicular phase, but few studies have investigated how increased energy intake at dinner influences sleep by considering the correlation between female hormone and cardiac autonomic nervous system (ANS) activity. This study examined the effects of energy intake at dinner on ANS activity during nighttime sleep in order to evaluate restorative sleep in healthy women. We also examined whether ANS activity is associated with female hormone dynamics.

METHODS

Twenty-four healthy collegiate women participated in this randomized crossover trial. Each was assigned to receive a High Energy Dinner (HED) or Low Energy Dinner (LED) treatment. Energy ratios of each test meal (breakfast, lunch, and dinner) to total energy intake were 1:1:2 and 1:2:1 for HED and LED treatments, respectively. Each participant wore an ECG recorder before dinner and removed it upon waking the next morning. Power spectral analysis of heart rate variability was used to calculate low frequency (LF), high frequency (HF), and total spectral power (TP). Cardiac sympathetic (SNS) and parasympathetic (PNS) nervous system activity were evaluated as LF/HF and HF/TP, respectively.

RESULTS

Mean HF/TP for the entire sleeping period was lower with HED treatment compared to LED treatment (41.7 ± 11.4 vs. 45.0 ± 12.13, P = .034). Intergroup comparisons of the initial 3-h sleeping period revealed that LF/HF (0.87 ± 0.82 vs. 0.66 ± 0.82, P = .013) and HF/TP (45.6 ± 13.9 vs. 51.5 ± 11.8, P = .002) were higher and lower, respectively, with HED treatment compared to LED treatment. Progesterone levels were positively correlated with LF/HF with LED treatment, and negatively correlated with HF/TP with both HED and LED treatments.

CONCLUSION

Higher energy intake at dinner increases and decreases SNS and PNS activities, respectively, resulting in nonrestorative nocturnal sleep. In addition, a negative correlation was observed between progesterone and PNS activity, highlighting the difficulty of increasing PNS activity during sleep in the luteal phase compared to the follicular phase.

A randomized, controlled, crossover study of appetite-related sensations after consuming snacks made from buckwheat

With the rising incidence of overweight and obesity in developed countries, there is an interest in developing food products that may aid in satiety and reduce energy intake. Buckwheat (Fagopyrum esculentum) is a gluten-free edible seed that has been previously shown to induce changes in postprandial concentrations of satiety hormones; however, subjective measures of appetite-related sensations and objective measures of energy intake at subsequent meals following buckwheat consumption have not been measured. Thirty-eight healthy adults were recruited to participate in a randomized, controlled, crossover trial with the main objective to determine if consuming snacks made from buckwheat would increase satiety and reduce energy intake compared with snacks comparable in serving size, physical characteristics, and nutrient composition. Water was included as a no-kilocalorie control. Participants received each of the treatments once separated by at least 7 days. Appetite related sensations were assessed using visual analog scales at fasting and after consuming the snack at 30-min intervals for 180 min. Lunch was provided at the clinic and the amount of food consumed was weighed. Participants recorded food intake for the rest of the day. Consuming buckwheat groats (32 g serving; 141 kcal) or pita bread made from buckwheat flour (50 g serving; 135 kcal) was not associated with changes in appetite related sensations or energy consumption compared with reference snack products made from corn or rice flour. Sensory questionnaires revealed that snacks made from buckwheat were liked to a similar degree or more as reference snack products, which shows commercial promise for developing buckwheat-containing snacks.

Objective and subjective measures of exercise intensity during thermo-neutral and hot yoga

While hot yoga has gained enormous popularity in recent years, owing in part to increased environmental challenge associated with exercise in the heat, it is not clear whether hot yoga is more vigorous than thermo-neutral yoga. Therefore, the aim of this study was to determine objective and subjective measures of exercise intensity during constant intensity yoga in a hot and thermo-neutral environment. Using a randomized, crossover design, 14 participants completed 2 identical ∼20-min yoga sessions in a hot (35.3 ± 0.8 °C; humidity: 20.5% ± 1.4%) and thermo-neutral (22.1 ± 0.2 °C; humidity: 27.8% ± 1.6%) environment. Oxygen consumption and heart rate (HR) were recorded as objective measures (percentage of maximal oxygen consumption and percentage of maximal HR (%HRmax)) and rating of perceived exertion (RPE) was recorded as a subjective measure of exercise intensity. There was no difference in exercise intensity based on percentage of maximal oxygen consumption during hot versus thermo-neutral yoga (30.9% ± 2.3% vs. 30.5% ± 1.8%, p = 0.68). However, exercise intensity was significantly higher during hot versus thermo-neutral yoga based on %HRmax (67.0% ± 2.3% vs. 60.8% ± 1.9%, p = 0.01) and RPE (12 ± 1 vs. 11 ± 1, p = 0.04). According to established exercise intensities, hot yoga was classified as light-intensity exercise based on percentage of maximal oxygen consumption but moderate-intensity exercise based on %HRmax and RPE while thermo-neutral yoga was classified as light-intensity exercise based on percentage of maximal oxygen uptake, %HRmax, and RPE. Despite the added hemodynamic stress and perception that yoga is more strenuous in a hot environment, we observed similar oxygen consumption during hot versus thermo-neutral yoga, classifying both exercise modalities as light-intensity exercise.

Postprandial energy metabolism and substrate oxidation in response to the inclusion of a sugar- or non-nutritive sweetened beverage with meals differing in protein content

Background

The macronutrient composition of the diet may play a more important role in maintaining a healthy body weight and preventing obesity than previously thought. The primary goal of this research was to determine the extent to which the simple addition of a small serving of a sugar-sweetened beverage (SSB) to meals with different macronutrient compositions impacts appetite, energy metabolism and substrate oxidation.

Methods

Appetite, energy metabolism and substrate oxidation were measured in 27 healthy weight adults (age = 23 ± 5 y; BMI = 23 ± 2 kg/m²) on two occasions in a room calorimeter after consuming a SSB or a non-nutritive-sweetened beverage (NNSB) with a standard (15%E) or high- (30%E) protein meal. Meal carbohydrate (CHO) content was adjusted to maintain equivalent calories for both study visits. All meals were composed of the same foods and provided 17 g of fat and 500 non-beverage calories. Study visits were separated by at least 1 week and menstruating females were studied during the luteal phase (Days 15-20). The effects of sex, protein level and beverage type and their interactions on satiety, appetite for foods with specific taste profiles, diet-induced thermogenesis (DIT) and rates of substrate oxidation were assessed using a 3-way Repeated Measures Analysis of Variance.

Results

Increasing dietary protein decreased hunger and increased satiety. Males were hungrier and less satisfied with the meals than females. Increasing dietary protein also decreased the desire to eat something savory, salty and fatty and the males had a greater appetite for food with these taste profiles. Interestingly, there was no effect of sex, dietary protein or beverage type on the desire to eat something sweet. The inclusion of a SSB markedly suppressed DIT (2.42% ± 5.91%) and fat oxidation (9.87 ± 11.09 g).

Conclusion

Appetite sensations, food preferences, energy expenditure and substrate oxidation are significantly altered in response to changes in meal macronutrient composition produced by modifications in the protein content of a meal and consumption of a SSB. Most notably, consumption of a SSB during a meal markedly reduces energy efficiency and fat oxidation independent of macronutrient composition.

Trial registrations

ClinicalTrials.gov: NCT02211599, registered August 05, 2014.

Change in women's eating habits during the menstrual cycle

OBJECTIVES

During the menstrual cycle, the influence of hormonal variations on dietary habits in women has been suggested by several studies. In this context, our work aimed to assess the spontaneous food intake and the anthropometric parameters of women at different periods of their menstrual cycles.

METHODS

This prospective study included 30 healthy women with regular periods (28 to 30 days), aged between 18 and 45. We assessed the spontaneous food intake and the anthropometric measurements (weight and waist circumference) of the participants, during the follicular, peri-ovulatory and luteal phases of their menstrual cycles.

RESULTS

Our results showed a slight but significant increase in body weight during the luteal phase (P=0.022) and the follicular phase (P=0.017) compared with the peri-ovulatory phase, without any significant change in waist circumference. The caloric intake increased during the peri-ovulatory (P<0.001) and the luteal phases (P<0.001), compared with the follicular phase, with a significant increase in carbohydrate (P<0.001), lipid (P=0.008) and protein (P=0.008) intake.

CONCLUSIONS

Our study showed a significant decrease in women's weight during the peri-ovulatory phase, with a significant increase in caloric intake during the luteal phase of the menstrual cycle. Divergent results have been reported by other authors and the physiopathology of these changes is still poorly understood.

Estradiol, SHBG and leptin interplay with food craving and intake across the menstrual cycle

OBJECTIVE

To understand the association between ovarian hormones, non-acute satiety hormones and craving calorie dense foods in the luteal phase.

METHODS

17 premenopausal women, mean age 23.2 y, mean BMI 22.4kg/m(2) with regular menstrual cycles were studied during late follicular (FP) and luteal phases (LP). Estradiol, progesterone, DHEAS, SHBG, insulin and leptin, were measured in fasting samples. The validated Food Craving Inventory was used to record the types of foods volunteers habitually ate - rich in fat, carbohydrate or sweet taste, as well as craved during the LP of their menstrual cycle.

RESULTS

Estradiol was inversely associated with leptin in FP (r=-0.62, p=0.01). Leptin was inversely associated with habitual intake of sweet foods, in both phases (FP: r=-0.64, p=0.01; LP: r=-0.63, p=0.01). SHBG in LP was positively associated with craving sweet and carbohydrate rich foods. Hierarchical cluster analysis revealed two groups of women, one with high estradiol, high estradiol/leptin ratio, high sweet and carbohydrate cravings (p<0.05); the other group had lower estradiol, lower estradiol/leptin ratio, and reported less craving.

CONCLUSIONS

The estradiol-leptin axis may be a determinant of luteal phase craving and habitual food intake in menstruating women.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01407692.

Changes in PYY and gastric emptying across the phases of the menstrual cycle and the influence of the ovarian hormones

Nutrition-related studies avoid the participation of pre-menopausal women due to the potential effect of the menstrual cycle (MC) on their appetite regulation. It is generally accepted that women increase their energy intake during the luteal phase (LPh) compared to the follicular (FPh), however what happens in the menstrual phase (MPh) and how this might be regulated remains uncertain. Although some research indicates changes in the gastric emptying (GE) velocity, whether PYY is affected by the MC phase, remains unknown. The aim of this study was to assess whether eating the same breakfast in each of the three MC phases would change the GE time, the PYY response and post-prandial satiety such that they might affect subsequent food intake. Furthermore, the aim was to associate any potential differences to the fluctuations in estradiol (E₂) and progesterone (P₄) within a MC. Nine naturally cycling women attended to the laboratory to consume a standardised breakfast on three occasions, each of them representing one of the MC phases. Breath samples to measure GE time, plasma samples to quantify PYY levels and hunger scores were collected for a total of 4 h after which food intake was assessed by an ad-libitum buffet lunch. GE and PYY levels changed significantly across the phases of the MC (p < 0.05). GE was correlated to P₄ and E₂-P₄ ratio (r = -0.5 and 0.4, respectively). To conclude, the appetite regulators PYY and GE time change depending upon the MC phases with GE time associated with the ovarian hormone levels which suggests the necessity of controlling the MC phase in studies looking at the appetite response.

Irregular meal-pattern effects on energy expenditure, metabolism, and appetite regulation: a randomized controlled trial in healthy normal-weight women

BACKGROUND

Obesity is increasing in parallel with greater all-day food availability. The latter may promote meal irregularity, dysregulation of the energy balance, and poor metabolic health.

OBJECTIVE

We investigated the effect of meal irregularity on the thermic effect of food (TEF), lipid concentrations, carbohydrate metabolism, subjective appetite, and gut hormones in healthy women.

DESIGN

Eleven normal-weight women (18-40 y of age) were recruited in a randomized crossover trial with two 14-d isoenergetic diet periods (identical foods provided and free living) that were separated by a 14-d habitual diet washout period. In period 1, participants followed a regular meal pattern (6 meals/d) or an irregular meal pattern (3-9 meals/d), and in period 2, the alternative meal pattern was followed. Before and after each period, when participants were fasting and for 3 h after intake of a test drink, measurements were taken of energy expenditure, circulating glucose, lipids (fasting only), insulin, glucagon-like peptide 1 (GLP-1), peptide YY (PYY), and ghrelin. An ad libitum test meal was offered. Subjective appetite ratings were assessed while fasting, after the test drink, after the ad libitum meal, and during the intervention. Continuous interstitial glucose monitoring was undertaken for 3 consecutive days during each intervention, and the ambulatory activity pattern was recorded (ambulatory energy expenditure estimation).

RESULTS

Regularity was associated with a greater TEF (P < 0.05) and a lower incremental area under the curve (iAUC) for glucose after intake of the test drink (over 3 h) and, for some identical meals, during the 2 interventions (over 90 min) (day 7: after breakfast; day 9: after lunch and dinner). There was no difference between treatments for the test-drink gut hormone response. A time effect was noted for fasting GLP-1, fasting PYY, PYY responses, and hunger-rating responses to the test drink (P < 0.05). Lower hunger and higher fullness ratings were seen premeal and postmeal during the regular period while subjects were free living.

CONCLUSION

Meal regularity appears to be associated with greater TEF and lower glucose responses, which may favor weight management and metabolic health. This trial was registered at clinicaltrials.gov as NCT02052076.

Differing effects of high-fat or high-carbohydrate meals on food hedonics in overweight and obese individuals

Although the effects of dietary fat and carbohydrate on satiety are well documented, little is known about the impact of these macronutrients on food hedonics. We examined the effects of ad libitum and isoenergetic meals varying in fat and carbohydrate on satiety, energy intake and food hedonics. In all, sixty-five overweight and obese individuals (BMI=30·9 (sd 3·8) kg/m2) completed two separate test meal days in a randomised order in which they consumed high-fat/low-carbohydrate (HFLC) or low-fat/high-carbohydrate (LFHC) foods. Satiety was measured using subjective appetite ratings to calculate the satiety quotient. Satiation was assessed by intake at ad libitum meals. Hedonic measures of explicit liking (subjective ratings) and implicit wanting (speed of forced choice) for an array of HFLC and LFHC foods were also tested before and after isoenergetic HFLC and LFHC meals. The satiety quotient was greater after ad libitum and isoenergetic meals during the LFHC condition compared with the HFLC condition (P=0·006 and P=0·001, respectively), whereas ad libitum energy intake was lower in the LFHC condition (P<0·001). Importantly, the LFHC meal also reduced explicit liking (P<0·001) and implicit wanting (P=0·011) for HFLC foods compared with the isoenergetic HFLC meal, which failed to suppress the hedonic appeal of subsequent HFLC foods. Therefore, when coupled with increased satiety and lower energy intake, the greater suppression of hedonic appeal for high-fat food seen with LFHC foods provides a further mechanism for why these foods promote better short-term appetite control than HFLC foods.

Effect of moderate- and high-intensity acute exercise on appetite in obese individuals

PURPOSE

The effect of acute exercise, and exercise intensity, on appetite control in obese individuals requires further study. The aim of this study was to compare the effects of acute isocaloric bouts (250 kcal) of high-intensity intermittent cycling (HIIC) and moderate-intensity continuous cycling (MICC) or short-duration HIIC (S-HIIC) (125 kcal) and a resting control condition on the appetite hormone responses, subjective feelings of appetite, energy intake (EI), and food reward in overweight/obese individuals.

METHODS

This study is a randomized crossover study on 12 overweight/obese volunteers. Participants were assigned to the control, MICC, HIIC, and S-HIIC conditions, 1 wk apart, in a counterbalanced order. Exercise was performed 1 h after a standard breakfast. An ad libitum test lunch was served 3 h after breakfast. Fasting/postprandial plasma samples of insulin, acylated ghrelin, polypeptide YY3-36, and glucagon-like peptide 1 and subjective feelings of appetite were measured every 30 min for 3 h. Nutrient and taste preferences were measured at the beginning and end of each condition using the Leeds Food Preference Questionnaire.

RESULTS

Insulin levels were significantly reduced, and glucagon-like peptide 1 levels significantly increased during all exercise bouts compared with those during rest. Acylated ghrelin plasma levels were lower in the MICC and HIIC, but not in S-HIIC, compared with those in control. There were no significant differences for polypeptide YY3-36 plasma levels, hunger or fullness ratings, EI, or food reward.

CONCLUSIONS

Our findings suggest that, in overweight/obese individuals, isocaloric bouts of moderate- or high-intensity exercise lead to a similar appetite response. This strengthens previous findings in normal-weight individuals that acute exercise, even at high intensity, does not induce any known physiological adaptation that would lead to increased EI.

Levels of Adipokines and Some Steroids During the Menstrual Cycle

The cyclical effects of hormones during the menstrual cycle (MC) are not just responsible for driving ovulation, but also have significant influence on dietary intake and appetite, as well as psychological and behavioral changes. The aim of our study was to describe changes and relationships between the MC and selected steroids, adipokines and food intake-related hormones. Twenty-seven women with regular menstrual cycles were included in the study, and their hormonal spectrum was measured in regular intervals starting from the first day of their cycle. Classical changes in gonadotropins, estrogens and progesterone during the menstrual cycle are accompanied by less striking but significant changes in 17-hydroxyprogesterone and testosterone. No significant changes show dehydroepiandrosterone and its 7-oxygenated metabolites. Adipokines show a tendency to increase during ovulation, while ghrelin and resistin decrease. There is also a remarkable association of sex hormone-binding globulin on the day of the cycle. Our results demonstrate that changes to adipokines during the menstrual cycle are not substantial, but nonetheless can play a role in the changes of food intake described in the literature. Precise descriptions of physiological changes in healthy women are important in helping us understand the significance of the changes accompanying various pathological states.

The late-luteal leptin level, caloric intake and eating behaviors among women with premenstrual dysphoric disorder

OBJECTIVES

A marked increased in food intake in the late-luteal phase is a characteristic symptom of premenstrual dysphoric disorder (PMDD). The aim of the study was to evaluate the leptin level, caloric intake, and eating behaviors of women with PMDD across the menstrual cycle among normal-weight and overweight subjects, respectively.

METHODS

A total of 62 women with PMDD and 69 controls were recruited following psychiatric interviewing and underwent prospective investigation. The leptin level, caloric intake, and three factors related to eating behavior were assessed in both the late-luteal and follicular phases.

RESULTS

The women with PMDD had greater increases in caloric intake, sweet caloric intake, and uncontrolled eating in the late-luteal phase than the controls. Among the normal-weight women, the leptin level was negatively correlated with caloric intake. The normal-weight women with PMDD had a lower leptin level, a lower leptin/body fat percentage (BFP), a higher caloric intake, and higher uncontrolled eating and emotional eating in the late-luteal phase than the normal-weight controls. Their leptin level was correlated negatively with sweet caloric intake. On the other hand, the overweight women with PMDD had a higher leptin level than the normal-weight women with PMDD and no decline was observed in their leptin level in the late-luteal phase. There were no differences in the leptin level between the overweight women with PMDD and the overweight controls. They also had a higher sweet caloric intake and higher uncontrolled eating and emotional eating than the overweight controls.

CONCLUSIONS

A decline in the leptin level is associated with late-luteal overeating among normal-weight women with PMDD. Hyperleptinemia and a high sweet caloric intake of overweight women with PMDD should be monitored and addressed in order to attenuate the risk of leptin resistance. The detailed roles of leptin and other psycho-neuro-endocrinology factors in the mechanism of overeating among women with PMDD should be evaluated in future study.

Altered food-cue processing in chronically ill and recovered women with anorexia nervosa

Anorexia nervosa (AN) is a severe mental disorder characterized by food restriction and weight loss. This study aimed to test the model posed by Brooks et al. (2012a,b) that women suffering from chronic AN show decreased food-cue processing activity in brain regions associated with energy balance and food reward (bottom-up; BU) and increased activity in brain regions associated with cognitive control (top-down; TD) when compared with long-term recovered AN (REC) and healthy controls (HC). Three groups of women, 15 AN (mean illness duration 7.8 ± 4.1 years), 14 REC (mean duration of recovery 4.7 ± 2.7 years) and 15 HC viewed alternating blocks of food and non-food images preceded by a short instruction during functional magnetic resonance imaging (fMRI), after fasting overnight. Functional region of interests (fROIs) were defined in BU (e.g., striatum, hippocampus, amygdala, hypothalamus, and cerebellum), TD (e.g., medial and lateral prefrontal cortex, and anterior cingulate), the insula, and visual processing areas (VPA). Food-cue processing activation was extracted from all fROIs and compared between the groups. In addition, functional connectivity between the fROIs was examined by modular partitioning of the correlation matrix of all fROIs. We could not confirm the hypothesis that BU areas are activated to a lesser extent in AN upon visual processing of food images. Among the BU areas the caudate showed higher activation in both patient groups compared to HC. In accordance with Brooks et al.'s model, we did find evidence for increased TD control in AN and REC. The functional connectivity analysis yielded two clusters in HC and REC, but three clusters in AN. In HC, fROIs across BU, TD, and VPA areas clustered; in AN, one cluster span across BU, TD, and insula; one across BU, TD, and VPA areas; and one was confined to the VPA network. In REC, BU, TD, and VPA or VPA and insula clustered. In conclusion, despite weight recovery, neural processing of food cues is also altered in recovered AN patients.

Epidemiology of Premenstrual Syndrome (PMS)-A Systematic Review and Meta-Analysis Study

BACKGROUND AND OBJECTIVES

Premenstrual Syndrome (PMS) is a common health problem in women in reproductive age. The present study aimed to investigate the prevalence of PMS using meta-analysis method.

METHODS

This meta-analysis systematically reviewed the prevalence of PMS. A search was conducted using keywords Premenstrual Syndrome, PMS, prevalence PMS and symptom of PMS in reliable English articles. The initial search 53 articles were available. After review of full-text articles, 17 articles were selected for analysis. Data were combined using meta-analysis (random effects model). Data were analyzed using STATA software, Version 11.1 RESULTS: Overall, 17 studies met our inclusion criteria. The pooled prevalence of PMS was 47.8% (95% CI: 32.6-62.9). The lowest and highest prevalence were reported in France 12% (95% CI: 11-13) and Iran 98% (95% CI: 97-100) respectively. However, meta-regression scatter plot showed an increasing trend in the prevalence of PMS during 1996-2011 but correlation between prevalence of PMS and year of study was not significance (p= 0.797).

INTERPRETATION AND CONCLUSIONS

Considering that different tools have been used in studies and many studies have been designed based on a limited sample, therefore, future research needs to consider the prevalence of PMS in different countries of world.

Fasting Leptin Is a Metabolic Determinant of Food Reward in Overweight and Obese Individuals during Chronic Aerobic Exercise Training

Changes in food reward have been implicated in exercise-induced compensatory eating behaviour. However, the underlying mechanisms of food reward, and the physiological correlates of exercise-induced changes in food reward, are unknown. Methods. Forty-six overweight and obese individuals completed 12 weeks of aerobic exercise. Body composition, food intake, and fasting metabolic-related hormones were measured at baseline, week six, and postintervention. On separate days, the reward value of high-and-low-fat food (explicit liking and implicit wanting) was also assessed at baseline, week six, and postintervention. Results. Following the intervention, FM, FFM, and VO2peak improved significantly, while fasting leptin decreased. However, food intake or reward did not change significantly. Cross-sectional analyses indicated that FM (P = 0.022) and FFM (P = 0.046) were associated with explicit liking for high-fat food, but implicit wanting was associated with FM only (P = 0.005). Fasting leptin was associated with liking (P = 0.023) and wanting (P = 0.021) for high-fat food. Furthermore, a greater exercise-induced decline in fasting leptin was associated with increased liking (P = 0.018). Conclusion. These data indicate that food reward has a number of physiological correlates. In particular, fasting leptin appears to play an active role in mediating food reward during exercise-induced weight loss.

Diurnal and menstrual cycles in body temperature are regulated differently: a 28-day ambulatory study in healthy women with thermal discomfort of cold extremities and controls

Diurnal cycle variations in body-heat loss and heat production, and their resulting core body temperature (CBT), are relatively well investigated; however, little is known about their variations across the menstrual cycle under ambulatory conditions. The main purpose of this study was to determine whether menstrual cycle variations in distal and proximal skin temperatures exhibit similar patterns to those of diurnal variations, with lower internal heat conductance when CBT is high, i.e. during the luteal phase. Furthermore, we tested these relationships in two groups of women, with and without thermal discomfort of cold extremities (TDCE). In total, 19 healthy eumenorrheic women with regular menstrual cycles (28-32 days), 9 with habitual TDCE (ages 29 ± 1.5 year; BMI 20.1 ± 0.4) and 10 controls without these symptoms (CON: aged 27 ± 0.8 year; BMI 22.7 ± 0.6; p < 0.004 different to TDCE) took part in the study. Twenty-eight days continuous ambulatory skin temperature measurements of distal (mean of hands and feet) and proximal (mean of sternum and infraclavicular regions) skin regions, thighs, and calves were carried out under real-life, ambulatory conditions (i-Buttons® skin probes, sampling rate: 2.5 min). The distal minus proximal skin temperature gradient (DPG) provided a valuable measure for heat redistribution from the core to the shell, and, hence, for internal heat conduction. Additionally, basal body temperature was measured sublingually directly after waking up in bed. Mean diurnal amplitudes in skin temperatures increased from proximal to distal skin regions and the 24-h mean values were inversely related. TDCE compared to CON showed significantly lower hand skin temperatures and DPG during daytime. However, menstrual cycle phase did not modify these diurnal patterns, indicating that menstrual and diurnal cycle variations in skin temperatures reveal additive effects. Most striking was the finding that all measured skin temperatures, together with basal body temperature, revealed a similar menstrual cycle variation (independent of BMI), with highest and lowest values during the luteal and follicular phases, respectively. These findings lead to the conclusion that in contrast to diurnal cycle, variations in CBT variation across the menstrual cycle cannot be explained by changes in internal heat conduction under ambulatory conditions. Although no measurements of metabolic heat production were carried out increased metabolic heat generation during the luteal phase seems to be the most plausible explanation for similar body temperature increases.

Sex differences in the effects of mental work and moderate-intensity physical activity on energy intake in young adults

The aim of this study was to examine the acute effects of mental work and moderate-intensity physical activity on various components of energy balance in young and healthy adults. With the use of a randomized crossover design, 35 participants aged 24 ± 3 years completed three 45-min conditions, namely, (i) resting in a sitting position (control), (ii) reading and writing (mental work (MW)), and (iii) exercising on a treadmill at 40% of peak oxygen uptake (exercise), followed by an ad libitum lunch. The endpoints were spontaneous energy intake (EI), energy expenditure (EE), appetite sensations, and EI for the remainder of the day. We observed that the energy cost of the control and MW conditions was about the same whereas the exercise condition increased EE to a greater extent in men than women. Exercise induced a decrease in EI relative to EE compared to the control condition that was more pronounced in men than women. However, women tended to increase their energy intake after the MW condition compared to the control one whereas an opposite trend was observed in men. None of the appetite sensation markers differed significantly between both sexes. In conclusion, men and women have specific food intake patterns when submitted to cognitive and physical stimuli.