The effects of meal patterns on liver steatosis, fibrosis, and biochemical factors in patients with nonalcoholic fatty liver disease: a randomized controlled clinical trial.

Background: This study was designed to compare the effects of four meal patterns on liver steatosis, fibrosis, and biochemical factors in patients with Nonalcoholic fatty liver disease (NAFLD). Methods: The 12-week intervention was performed on 123 patients with NAFLD who were randomly allocated into four groups: "3-meals", "skipping breakfast", "skipping dinner", and " 3 meals and 3 snacks per day." group. The assessment of liver steatosis, fibrosis, biochemical factors, and anthropometrical evaluation were performed at baseline and at end of the study. Results: A significant improvement was found in the liver steatosis and fibrosis among the patients who consumed 3 meals, 3 snacks compared to the other groups (P < 0.001). In addition, a higher reduction was observed in serum levels of alanine amino transferase (ALT) (20.93 ± 23.37 mg/dl, P < 0.001), aspartate aminotransferase (AST) (17.15 ± 16.48 mg/dl, P < 0.001), gamma-glutamyl transferase(GGT) (13.43 ± 13.41 mg/dl; P < 0.001), and alkaline phosphatase (ALK) (47.19 ± 60.51 mg/dl; P = 0.004) in patients who consumed 3 meals, 3 snacks, while the concentration of liver enzymes in patients who consumed 3 meals increased significantly. At the end of the study, there was a significant increase in the fasting blood sugar (FBS) concentration in the "skipping breakfast" group (17.51 ± 38.85 mg/dl; P = 0.011) and "3-meals" group (17.51 ± 38.85 mg/dl, P = 0.03). Conclusion: Consuming 3 meals, 3 snack per day significantly improves disease severity and biochemical factors in NAFLD patients. Further studies are warranted. Trial registration number: : IRCT20201010048982N2. Name of the registry: Urmia University of Medical Sciences. Date of registration: 2021-08-22, 1400/05/31. URL of trial registry record: https://www.irct.ir/search/result?query=IRCT20201010048982N2. Supplementary Information: The online version contains supplementary material available at 10.1007/s40200-023-01375-2.

Chrono-nutrition and sleep: lessons from the temporal feature of eating patterns in human studies - A systematic scoping review.

An emerging field of research has revealed a bidirectional relationship between sleep and diet, highlighting the potential role of a healthy diet in improving sleep. However, the impact of chrono-nutrition on sleep remains less explored. Here we conducted a systematic scoping review, considering the multiple dimensions of chrono-nutrition, to describe the extent, range, and nature of the existing literature in this area (PROSPERO: CRD42021274637). There has been a significant increase in the literature exploring this topic over the past six years (almost 67 % of the evolving literature). A breakdown of the included studies was performed according to three major chrono-nutritional dimensions: meal timing [n = 35], irregular eating patterns [n = 84], and frequency of eating occasions [n = 3]. Meal timing included three sub-dimensions: breakfast skipping [n = 13], late eating [n = 16], and earlier vs later meals schedules [n = 6]. Irregular meal patterns included three sub-dimensions: diurnal fasting [n = 65], intermittent fasting [n = 16], and daily meal patterns [n = 3]. Frequency was the least studied dimension (n = 3). We provided a synthetic and illustrative framework underlining important preliminary evidence linking the temporal characteristics of eating patterns to various facets of sleep health. Nonetheless, much work remains to be done to provide chrono-nutrition guidelines to improve sleep health in the general population.

A systematic review of associations between day-to-day variability in meal pattern and body weight, components of the metabolic syndrome and cognitive function.

BACKGROUND: Meal pattern is a potential health determinant. Previously, mean values for properties of meal pattern, such as daily meal frequency, have been considered. Means, however, obscure variability between-day (irregular or chaotic eating). This systematic review aimed to identify and critique published methods used to characterise between-day variability in meal pattern, and to explore relationships between this and obesity, as well as associated health outcomes. METHODS: Using relevant databases, a systematic search was undertaken for studies with adults and children in which between-day variability in meal pattern was measured, and related to body weight, metabolic syndrome components and cognitive function. RESULTS: In 34 papers identified (28 observational and six intervention studies), between-day variability in meal pattern was characterised by a variety of methods. These ranged from single questions about intake regularity to more complex methods quantifying the degree of variability. Assumptions were made, such as there being three main meals, resulting in dissociation from the "clock time" of eating. In 24 of the papers, between-day variability in meal pattern was associated with negative weight and health outcomes including higher weight, reduced thermogenic response to meals and poorer academic achievement. CONCLUSIONS: Between-day variability in meal pattern is a promising research area that might inform low-cost public health interventions. However, current methods of characterising between-day variability tend to make assumptions and be inconsistent in the meal pattern properties considered. Well controlled dietary intervention studies are required to confirm causation.

In Which Situations Do We Eat? A Diary Study on Eating Situations and Situational Stability.

Eating situations are crucial for understanding and changing eating behavior. While research on individual situational dimensions exists, little is known about eating situations as a whole. This study aimed to fill this gap by identifying eating situations as combinations of multiple situational dimensions and describing how stable individuals eat in those situations. In a five-day online diary study, 230 participants reported a total of 2461 meals and described the corresponding eating situation using predefined situational dimensions. Divisive hierarchical cluster analyses were conducted separately for breakfast, lunch, and dinner, resulting in unique cluster solutions that characterized the most common eating situations. The most common breakfast situations were characterized by a combination of the dimensions social, affect, and hunger. The most common lunch and dinner situations were characterized by varying combinations of the dimensions social, affect, and activity. Based on the identified situations, a situational stability index was developed to describe how stable individuals eat in the same situations. The findings suggest high interindividual differences in situational stability, which were associated with socio-demographic characteristics like age or employment. This study enhances our understanding of the situational aspects of eating behavior while offering tools to describe eating situations and situational stability.

Exploring oral health indicators, oral health-related quality of life and nutritional aspects in 23 medicated patients from a short-term psychiatric ward.

Background: Patients suffering from psychiatric disorders face many difficulties due to their condition, medications and lifestyle. Oral health and nutrition may be affected, further complicating their lives. Our aim was to provide in-depth information on oral health and nutritional factors in a small group of patients in short-term psychiatric ward. Methods: Twenty-three patients (mean age 36, average medications five) were recruited during short-term hospitalization in a psychiatric ward. Inclusion criteria: anxiety, psychosis and/or depression, and use of at least one antidepressant or anxiolytic/antipsychotic drug with xerostomia as a known side effect. Subjective oral dryness was evaluated using the Shortened Xerostomia Inventory (SXI). Oral examination included Clinical Oral Dryness Score (CODS), secretion of unstimulated (UWS) and stimulated whole saliva (SWS), and evaluation of dental, gingival, and periodontal status. Self-reported complaints of oral disorders were recorded. The Oral Health Impact Profile-14 (OHIP-14) was used to explore oral health-related quality of life. Nutritional status was assessed using the Patient-Generated Subjective Global Assessment Short Form (PG-SGA-SF), and diet quality was assessed using the Mediterranean diet score (KIDMED). Results: Compared to healthy controls, the patients had significantly higher SXI scores and CODS, and SWS secretion was lower. Complaints of dysgeusia and halitosis were significantly more frequent among patients. Gingivitis was more common in patients. OHIP-14 scores were much higher in the patients, and they reported significantly poorer oral and general health. Most patients lacked a regular meal pattern. Very low diet quality was observed in five patients, while improvements were needed in twelve. "Dry mouth" and "No appetite, just did not feel like eating" were the most common symptoms preventing patients from eating enough. The PG-SGA-SF symptoms component score showed a strong negative correlation with self-reported oral health, and a strong positive correlation with OHIP-14. Conclusion: This relatively small group of patients in short-term psychiatric ward had both reduced oral health and poor oral health-related quality of life. Furthermore, their nutritional intake was affected by their oral health problems. Although larger groups need to be studied, these findings indicate that oral health and nutrition should be evaluated and adjusted in these patients to improve their overall care.

Bidirectional mediation of evening energy proportion and chronotype on their associations with blood lipid levels in a Chinese population.

The bidirectional relationship between chronotype and meal energy distribution, and the effect of their relationship on blood lipid level has not been investigated. This study aims to test and compare the bidirectional mediating effects of chronotype and meal energy distribution on blood lipid levels. Data of 9376 adult participants from 2018 wave of the China Health and Nutrition Survey (CHNS) were analysed. Two mediation models were tested and compared: one with Evening energy proportion (Evening EI%) as mediator of the association between adjusted mid-sleep time on free days (MSFa) and blood lipid levels and the other with MSFa as mediator of the association of Evening EI% with blood lipid levels. The mediating effect of Evening EI% on the association between MSFa and TC, LDL-C and non-HDL-C were significant (p < .001, p = .001, and p = .002, respectively). The mediating effect of MSFa on the association between Evening EI% and TC, LDL-C and non-HDL-C were significant (p = .006, p = .035, and p < .001 respectively). Evening EI% had a larger standardized mediation effect compared to MSFa. The bidirectional mediation effect suggests a reinforcement mechanism, in which later chronotype and higher Evening EI% reciprocally influence their negative impact on elevated blood lipid levels, leading to higher risk of cardiovascular diseases in the general population.

Feeding Behavior of Finishing Pigs under Diurnal Cyclic Heat Stress.

The impact of cyclic heat stress (CHS) and turning the lights on and off on pig feeding behavior (FB) was investigated. The FB of 90 gilts was recorded in real-time under two ambient temperatures (AT): thermoneutrality (TN, 22 °C) or CHS (22/35 °C). The day was divided into four periods: PI (06-08 h); PII (08-18 h); PIII (18-20 h); and PIV (20-06 h). Automatic and Intelligent Precision Feeders recorded each feed event for each pig. An estimated meal criterion (49 min) was used to calculate the FB variables. Feed behavior in both ATs followed a circadian pattern. The CHS reduced the feed intake by 6.9%. The pigs prioritized feed intake during the coolest hours of the day; however, nocturnal cooling did not allow the pigs to compensate for the reduced meal size due to CHS. The highest meal size and most of the meals were observed during the lighting-on period. The pigs reduced their interval between meals during PII and PIII. The lighting program increased the meal size when the lights were switched on and reduced the meal size when the lights were switched off. Thus, the dynamics of the FB were largely influenced by AT, whereas the meal size was affected by the lighting program.

Effect of Dysphagia on the Older Adults' Nutritional Status and Meal Pattern.

INTRODUCTION/OBJECTIVES: Dysphagia is a widespread clinical condition among older adults. Although known as a risk factor for nutritional status and dehydration, dysphagia also affects meal patterns. This study aimed to determine the relationship between dysphagia and undernutrition, as well as dietary consumption patterns in older adults. METHODS: 268 older adults (144 women, 124 men) were included in the study. Mini Nutritional Assessment (MNA), dysphagia assessment (EAT-10), oral examination, and Semi-quantitative Food Frequency Questionnaire (SFFQ) were used for collecting data. Odds ratio and Chi square were used to compare independent variables in subjects with and without undernutrition as well as those who intake texture modified and non-texture modified diet. RESULTS: Mean age of the undernutrition and normal nutrition groups was 68.9 ± 6.1 and 68.8 ± 6.0 years, respectively. The undernutrition group's activities of daily living (ADL) were 19.7 ± 0.9, and the normal nutrition group was 19.8 ± 0.7. Older adults with dysphagia were 4.8 times more likely to experience undernutrition than older adults without dysphagia (95% CI = 1.75-13.13, P = .002). There was a statistically difference between the meal patterns among the dysphagic older adult group and the normal-swallowing older adults' group at the .05 level. CONCLUSIONS: According to this study, dysphagia was associated with the nutritional status of older adults and dietary patterns. The study results suggested some recommendations for dental health personnel on oral care related to dietary consumption and dietary patterns in older adults.

Associations of chronotype and social jetlag with eating jetlag and their changes among German students during the first COVID-19 lockdown. The Chronotype and Nutrition study.

Due to their biologically later chronotype, young students are vulnerable to a discrepant sleeping pattern between work- and free days, coined social jetlag (SJL). This study examined whether a later chronotype and/or a larger SJL are related to an analogous discrepancy in meal timing defined as eating jetlag (EJL) and whether chronotype and/or changes in SJL during the first COVID-19 related lockdown in Germany associated with changes in EJL. Baseline data were collected from September 2019-January 2020 among 317 students (58% females) aged 18-25 years of which a total of 156 students (67% females) completed an online follow-up survey in June-July 2020 (1st lockdown). Data were collected on daily routines, timing of meals/snacks, and physical activity. Chronotype was determined using the Munich ChronoType Questionnaire; SJL and EJL correspond to the difference in the daily midpoint of sleep/eating duration between work- and free days. Multivariable linear regression revealed that students with a later chronotype or a larger SJL experienced a larger EJL (padjusted = 0.0124 and padjusted<0.0001). A later chronotype at baseline and reductions in SJL during lockdown associated with concurrent reductions in EJL (padjusted = 0.027 and padjusted<0.0001). In conclusion, students with a later chronotype exhibit a more erratic meal pattern, which associates with SJL. During lockdown, flexible daily schedules allowed students to align the meal timing with their inner clock.

High dietary cation and anion difference formulation increased heat dissipation in non-lactating goats fed at high ambient temperature.

Background and Aim: In our previous study, we observed that a high dietary cation and anion difference (DCAD) of 40 mEq/kg dry matter (DM) in the diets of lactating dairy goats increased heat dissipation. In the present study, we believe that the level of DCAD fed to non-lactating and non-pregnant goats was twice as high as that fed to lactating goats in our previous study. This increase could have resulted in a greater water balance due to increased intake of water and unchanged urinary excretion. Therefore, this study aimed to determine the behavioral and heat dissipation effects of a dietary shift from low to high DCAD levels in dairy goats under tropical conditions. Materials and Methods: Seven non-lactating and non-pregnant crossbred goats were used in this study. All animals were initially fed a low DCAD (15 mEq/100 g DM) diet from days 0-6 and then switched to a high DCAD (89 mEq/100 g DM) diet from day 7 (high DCAD-7) to day 18 (high DCAD-18). Results: The results revealed that a high DCAD increased DM intake from days 13-18 (p < 0.05). The larger daily meal size associated with the high DCAD-18 group was due to increased daytime meal sizes, not nighttime when compared to the low DCAD group. Dietary cation and anion difference supplementation did not affect daily water intake; however, drinking patterns differed between the low DCAD group and the high DCAD-7 group from 07:00 to 09:00 and during nighttime. Similarly, daily urine volume was unaffected by DCAD supplementation, but urinary patterns differed between the low DCAD and high DCAD-18 groups. The daily water balance remained unchanged across all treatments, yet, a higher morning water balance was observed in the high DCAD group. The high DCAD diet led to an increase in respiration rate and rectal temperature compared to the low DCAD diet. Conclusion: The observed eating, drinking, and urinary patterns collectively suggested that high DCAD supplementation mitigates the effects of heat stress in non-lactating goats fed at high ambient temperatures.

An oral gavage of lysine elicited early satiation while gavages of lysine, leucine, or isoleucine prolonged satiety in pigs.

Excess dietary amino acids (AA) may negatively affect feed intake in pigs. Previous results showed that Lys, Leu, Ile, Phe, and Glu significantly increased gut peptide secretion (i.e., cholecystokinin, glucagon-like peptide 1). However, the link between dietary AA and gut peptide secretion with changes in feeding behavior patterns has not been demonstrated to date in pigs. The aim of the present study was to determine the effect of Lys, Leu, Ile, Phe, and Glu, on feed intake and meal patterns in young pigs. Twelve male pigs (Landrace × Large White, body weight = 16.10 ± 2.69 kg) were administered an oral gavage of water (control) or Lys, Leu, Ile, Phe, Glu, or glucose (positive control) at 3 mmol.kg-1 following an overnight fasting. The experiment consisted in measuring individual feed disappearance and changes in meal pattern (including latency to first meal, first meal duration, intermeal interval, second meal duration, and number of meals) based on video footage. Compared to the control group Lys significantly (P ≤ 0.01) reduced feed intake during the first 30 min and up to 2.5 h post-gavage, including a reduction (P ≤ 0.05) in the first meal duration. Similarly, Leu and Ile also significantly decreased feed intake up to 3 h post-gavage on a cumulative count. However, the strongest (P ≤ 0.01) impacts on feed intake by the two branched chained AA were observed after the first- or second-hour post-gavage for Leu or Ile, respectively. In addition, Leu or Ile did not affect the first meal duration (P ≥ 0.05). Leu significantly increased (P ≤ 0.01) the intermeal interval while decreasing (P ≤ 0.05) the number of meals during the initial 2 h following the gavage when compared with the control group. In contrast, the oral gavages of Phe or Glu had no significant impact (P > 0.05) on the feeding behavior parameters measured relative to the control pigs. In turn, glucose had a short-lived effect on appetite by reducing (P < 0.05) feed intake for 30 min after the first-hour post-gavage. In conclusion, the impact of an oral gavage of Lys on feeding behavior is compatible with a stimulation of early satiation and an increased duration of satiety. The main impact of the oral gavages of Leu and Ile was an increase in the duration of satiety. The gastrointestinal mechanisms associated with non-bound dietary AA sensing and the impact on voluntary feed intake warrant further investigations.

A better understanding of the impact of individual dietary amino acids on feeding behavior in pigs can help improve current feed formulation practices. Lys, Leu, Ile, Phe, or Glu were selected based on the impact on gut peptide secretion from a previous study, to assess the effect on feed intake and meal pattern using an oral gavage model (3 mmol.kg−1) in young pigs. The oral gavage of Lys resulted in early satiation as indicated by the reduction of the first meal duration and the feed intake within the first 30 min post-gavage. In addition, the Lys group showed reduced feed intake up to 3 h post-gavage, interpreted as an extended duration of the post first meal satiety compared to the control. The latter was also observed for the branched chained amino acids (BCAA) Leu and Ile. The Leu gavage resulted in an increased intermeal interval together with a reduction on the number of meals while Ile, in turn, reduced feed intake particularly during the third hour post-gavage. No significant effects of the Phe or Glu gavages on feeding behaviors were observed. Overall, these results suggest that dietary Lys, Leu, or Ile had significant anorexigenic effects. Lys increased both satiation and satiety while the BCAA Leu and Ile, mainly increased post-meal satiety in pigs.

Meal-specific dietary patterns and their contribution to habitual dietary patterns in the Iranian population.

Recent studies have focused on habitual intake without addressing meal-specific intakes. We aimed to identify meal-specific dietary patterns and their contribution to habitual dietary patterns. This cross-sectional study was conducted on 838 adults, both sexes who attended the health centres in Tehran. Dietary data were recorded by three 24-h dietary recalls (24hDR). Dietary patterns were identified by using principal component analysis on meal-specific and overall food intakes. Intraclass correlation (ICC) was used as a measurement of consistency across meals and days. Correlation analysis and linear regression (partial R2) were used for meals contribution. Four habitual dietary patterns were derived from average dietary intake of 3-d 24hDR labelled as 'Western', 'Healthy', 'Traditional' and 'Legume and broth'. Also, we identified two major dietary patterns on each meal level (factor 1 and 2 for breakfast, lunch, afternoon snack and dinner). The highest contribution of energy intake was observed in lunch (25·7 %), followed by dinner (20·81 %). Consistency of food groups was the highest across days (ICC tea = 0·58) and breakfasts (ICC tea = 0·60). Dinner had a strong correlation coefficient with the 'Western' habitual dietary pattern then followed by lunch. Similarly, dinner and lunch contributed the most (r and partial R2) to the 'Western' habitual dietary pattern. Our results suggest that habitual dietary patterns to several extents are formed at meal levels, and dinner has a greater contribution to the habitual dietary patterns in Iranian people. This may help planning for local dietary guidelines according to the time of eating to promote public health.

A new apparatus to analyze meal-related ingestive behaviors in rats fed a complex multi-food diet.

The measurement of the size and timing of meals provides critical insight into the processes underlying food intake. While most work has been conducted with a single food or fluid, the availability of food choices can also influence eating and interact with these processes. The 5-Item Food Choice Monitor (FCM), a device that continuously measures eating and drinking behaviors of rats provided up to 5 foods and 2 fluids simultaneously, was designed to allow study of food choices simultaneously with meal patterns. To validate this device, adult male and female (n = 8 each) Sprague-Dawley rats were housed in the FCM. Food and fluid intake were measured continuously (22-h/day) while rats were presented water and powdered chow. Then a cafeteria diet of 5 foods varying in macronutrient content, texture, and flavors were offered along with water. Lastly, the 5 foods were offered along with 0.3 M sucrose and water. Analyses were conducted to find optimal criteria for parceling ingestive behavior into meals, and then meal patterns were quantified. Total intake, as assessed by FCM software, was in good concordance with that measured by an independent scale. A minimum meal size of 1 kcal and a meal termination criterion of 15-min accounted for >90% of total intake and produced meal dynamics that were in register with the literature. Use of the cafeteria diet allowed comparisons between meal patterns with a single food versus a multi-food diet, as well as analyses of macronutrient-related food choices across subsets of meals. The FCM proved to accurately measure food intake over a 22-h period and was able to detect differences and similarities in the meal patterns of rats as a function of sex and food choice availability. Combined with any number of experimental manipulations, the FCM holds great promise in the investigation of the physiological and neural controls of ingestive behavior in a dietary environment that allows food choices, more closely emulating human eating conditions.

Face Validity of Observed Meal Patterns Reported with 7-Day Diet Diaries in a Large Population-Based Cohort Using Diurnal Variation in Concentration Biomarkers of Dietary Intake.

In a cross-sectional analysis of a population-based cohort (United Kingdom, N = 21,318, 1993-1998), we studied how associations between meal patterns and non-fasting triglyceride and glucose concentrations were influenced by the hour of day at which the blood sample was collected to ascertain face validity of reported meal patterns, as well as the influence of reporting bias (assessed using formula of energy expenditure) on this association. Meal size (i.e., reported energy content), mealtime and meal frequency were reported using pre-structured 7-day diet diaries. In ANCOVA, sex-specific means of biomarker concentrations were calculated by hour of blood sample collection for quartiles of reported energy intake at breakfast, lunch and dinner (meal size). Significant interactions were observed between breakfast size, sampling time and triglyceride concentrations and between lunch size, sampling time and triglyceride, as well as glucose concentrations. Those skipping breakfast had the lowest triglyceride concentrations in the morning and those skipping lunch had the lowest triglyceride and glucose concentrations in the afternoon, especially among acceptable energy reporters. Eating and drinking occasion frequency was weakly associated with glucose concentrations in women and positively associated with triglyceride concentrations in both sexes; stronger associations were observed for larger vs. smaller meals and among acceptable energy reporters. Associations between meal patterns and concentration biomarkers can be observed when accounting for diurnal variation and underreporting. These findings support the use of 7-day diet diaries for studying associations between meal patterns and health.

The relationship between the risk of eating disorder and meal patterns in University students.

PURPOSE: This study was carried out to evaluate the relation between meal patterns and the risk of eating disorders in university students. METHODS: The study was conducted on a total of 331 volunteer students with a mean age of 22.08 ± 1.80 years, 56.5% female. Participants' sociodemographic characteristics, health information and eating habits like meal skipping and dieting were questioned. Sick, Control, One stone, Fat, Food (SCOFF) Eating Disorders Scale and Eating Disorder Examination Questionnaire (EDE-Q) were used to determine eating behavior disorders, with face to face interviews by the researches. RESULTS: A significant correlation was found between dieting and skipping meals and the risk of eating disorders in both genders (p < 0.05). In addition, when the reasons for skipping meals were questioned, a significant relationship was detected between skipping meals and eating behaviour disorders by 3.285 times (p = 0.000). Also, every unit of increase in body mass index (BMI) values of individuals who participated to the study led to an increase in eating disorders by a factor of 1.262 (p = 0.000). CONCLUSIONS: Our findings support concerns about the negative health effects of increasing overweight among university students in accordance with the data that the increase in BMI values led to an increase in eating disorders. Notably a significant correlation was found between dieting, skipping meals and the risk of eating disorders in both genders it is highlighting the need for monitoring and early diagnosis of eating disorders in youth with simple scales like SCOFF. LEVEL OF EVIDENCE: Level V, cross-sectional descriptive study.

Effect of Growth Hormone Secretagogue Receptor Deletion on Growth, Pulsatile Growth Hormone Secretion, and Meal Pattern in Male and Female Mice.

INTRODUCTION: While the vast majority of research investigating the role of ghrelin or its receptor, GHS-R1a, in growth, feeding, and metabolism has been conducted in male rodents, very little is known about sex differences in this system. Furthermore, the role of GHS-R1a signaling in the control of pulsatile GH secretion and its link with growth or metabolic parameters has never been characterized. METHODS: We assessed the sex-specific contribution of GHS-R1a signaling in the activity of the GH/IGF-1 axis, metabolic parameters, and feeding behavior in adolescent (5-6 weeks old) or adult (10-19 weeks old) GHS-R KO (Ghsr-/-) and WT (Ghsr+/+) male and female mice. RESULTS: Adult Ghsr-/- male and female mice displayed deficits in weight and linear growth that were correlated with reduced GH pituitary contents in males only. GHS-R1a deletion was associated with reduced meal frequency and increased meal intervals, as well as reduced hypothalamic GHRH and NPY mRNA in males, not females. In adult, GH release from Ghsr-/- mice pituitary explants ex vivo was reduced independently of the sex. However, in vivo pulsatile GH secretion decreased in adult but not adolescent Ghsr-/- females, while in males, GHS-R1a deletion was associated with reduction in pulsatile GH secretion during adolescence exclusively. In males, linear growth did not correlate with pulsatile GH secretion, but rather with ApEn, a measure that reflects irregularity of the rhythmic secretion. Fat mass, plasma leptin concentrations, or ambulatory activity did not predict differences in GH secretion. DISCUSSION/CONCLUSION: These results point to a sex-dependent dimorphic effect of GHS-R1a signaling to modulate pulsatile GH secretion and meal pattern in mice with different compensatory mechanisms occurring in the hypothalamus of adult males and females after GHS-R1a deletion. Altogether, we show that GHS-R1a signaling plays a more critical role in the regulation of pulsatile GH secretion during adolescence in males and adulthood in females.

Impact of isoenergetic intake of irregular meal patterns on thermogenesis, glucose metabolism, and appetite: a randomized controlled trial.

BACKGROUND: Evidence is emerging that interdaily meal pattern variability potentially affects response such as thermic effect of food (TEF), macronutrient metabolism, and appetite. OBJECTIVES: To investigate the effect of irregular meal pattern on TEF, glucose, insulin, lipid profile, and appetite regulation in women who are overweight or with obesity and confirmed insulin resistance. DESIGN: In a randomized crossover trial, 9 women [mean ± SD BMI (in kg/m2): 33.3 ± 3.1] with confirmed insulin resistance consumed a regular (14 d; 6 meals/d) and an irregular (14 d; 3-9 meals/d) meal pattern separated by a 14-d washout interval. Identical foods were provided during the interventions, and at the start and end of each meal pattern, participants attended the laboratory after an overnight fast. Energy expenditure, glucose, insulin, lipids, adiponectin, leptin, glucagon-like peptide 1 (GLP-1), peptide YY (PYY), and ghrelin were measured at baseline and for 3 h after consumption of a test drink, after which an ad libitum test meal was offered. Subjective appetite ratings were recorded before and after the test drink, after the ad libitum meal, and during the intervention. Continuous interstitial glucose monitoring was undertaken for 7 consecutive days during each intervention. RESULTS: TEF (over 3 h) was significantly lower postirregular intervention compared with postregular (97.7 ± 19.2 kJ*3 h in postregular visit and 76.7 ± 35.2 kJ*3 h in postirregular visit, paired t test, P = 0.048). Differences in HOMA-IR between the 2 interventions (3.3 ± 1.7 and 3.6 ± 1.6 in postregular and postirregular meal pattern, respectively) were not significant. Net incremental AUC for GLP-1 concentrations (over 3 h) for the postregular meal pattern were higher (864.9 ± 456.1 pmol/L*3 h) than the postirregular meal pattern (487.6 ± 271.7 pmol/L*3 h, paired t test, P = 0.005). CONCLUSIONS: Following a 14-d period of an irregular meal pattern, TEF was significantly less than following a regular meal pattern, potentially compromising weight management if sustained long term. This study was registered at www.clinicaltrials.gov as NCT02582606.

Meal Patterns and Food Choices of Female Rats Fed a Cafeteria-Style Diet Are Altered by Gastric Bypass Surgery.

After Roux-en-Y gastric bypass surgery (RYGB), rats tend to reduce consumption of high-sugar and/or high-fat foods over time. Here, we sought to investigate the behavioral mechanisms underlying these intake outcomes. Adult female rats were provided a cafeteria diet comprised of five palatable foodstuffs varying in sugar and fat content and intake was monitored continuously. Rats were then assigned to either RYGB, or one of two control (CTL) groups: sham surgery or a nonsurgical control group receiving the same prophylactic iron treatments as RYGB rats. Post-sur-gically, all rats consumed a large first meal of the cafeteria diet. After the first meal, RYGB rats reduced intake primarily by decreasing the meal sizes relative to CTL rats, ate meals more slowly, and displayed altered nycthemeral timing of intake yielding more daytime meals and fewer nighttime meals. Collectively, these meal patterns indicate that despite being motivated to consume a cafeteria diet after RYGB, rats rapidly learn to modify eating behaviors to consume foods more slowly across the entire day. RYGB rats also altered food preferences, but more slowly than the changes in meal patterns, and ate proportionally more energy from complex carbohydrates and protein and proportionally less fat. Overall, the pattern of results suggests that after RYGB rats quickly learn to adjust their size, eating rate, and distribution of meals without altering meal number and to shift their macronutrient intake away from fat; these changes appear to be more related to postingestive events than to a fundamental decline in the palatability of food choices.

Rats Self-Select a Constant Protein-to-Carbohydrate Ratio Rather Than a Constant Protein-to-Energy Ratio and Have Low Plasma FGF21 Concentrations.

BACKGROUND: Under dietary self-selection (DSS), rats ingest 25-30% of energy as protein. This high level appears to be explained by metabolic benefits related to reduced carbohydrate dependence and associated pathologies. However, the mechanisms underlying these choices remain largely misunderstood. OBJECTIVES: The aim was to test the hypothesis that in a DSS model, rats select a protein-to-energy (PE) ratio to maintain the protein-to-carbohydrate (PC) ratio constant and that fibroblast growth factor 21 (FGF21) is involved in this response. METHODS: Adult male Wistar rats were used in 3 experiments. The first was to determine whether the PE ratio was influenced by changes in carbohydrate content. The second was to test whether the PE ratio was defended with a modified DSS model. The third was to determine whether the selected PE ratio was of metabolic interest compared with a standard 15% protein diet. Food intake, body weight, and energy expenditure were measured. After 3 wk, plasma was sampled and rats were killed to determine body composition and gene expression. Statistical analyses were mainly done by ANOVA tests and correlation tests. RESULTS: The selected PE ratio increased from 20% to 35% when the carbohydrate content of the protein-free diet increased from 30% to 75% (R2 = 0.56; P < 10-6). Consequently, the PC ratio was constant (70%) in all groups (P = 0.18). In self-selecting rats, plasma FGF21 concentrations were 3 times lower than in rats fed the 5% protein diet (P < 10-4) and similar to those in rats fed a 30% diet. CONCLUSIONS: This study showed that self-selecting rats established PE ratios larger than those considered sufficient to achieve optimal growth in adult rats (10-15%), and the ratios were highly dependent on carbohydrates, apparently with the aim of maintaining a constant and high PC ratio. This was associated with a minimization of plasma FGF21.

Breakfast Frequency Is Inversely Associated with Weight Gain in a Cohort of Mexican Women.

BACKGROUND: Food timing affects circadian rhythms involved in weight control. Regular consumption of breakfast may affect body weight. OBJECTIVE: We examined the relation between breakfast frequency with weight change in middle-age women over a 3-y period. METHODS: We used data from 65,099 nonpregnant women aged >20 y participating in the Mexican Teachers' Cohort (MTC) who at baseline (2006-2008) were cancer free and for whom self-reported breakfast frequency at baseline was available. We analyzed body weight change between baseline and the first follow-up (2011) according to breakfast frequency. Participants were classified according to baseline breakfast frequency 0, 1-3, 4-6, or 7 d/wk and meal frequency 1-2, 3-4, or ≥5 meals/d. We used linear and modified Poisson regression to analyze body weight change as a continuous variable and for weight gain ≥5 kg (yes/no), respectively. Models were adjusted for sociodemographic and lifestyle confounders. RESULTS: At baseline, 25% of participants were daily breakfast consumers and 18.4% of women increased ≥5 kg between 2008 and 2011. The prevalence of weight gain ≥5 kg among daily breakfast consumers was 7% lower than among those who skipped breakfast (prevalence ratio: 0.93; 95% CI: 0.89, 0.97; P-trend = 0.02). The association was stronger among normal-weight women at baseline with a corresponding estimate of 0.87 (95% CI: 0.79, 0.97; P-trend = 0.02). CONCLUSION: Daily breakfast consumption was inversely associated with weight gain ≥5 kg over 3 y in middle-aged Mexican women. Regular breakfast may be an important dietary factor for body weight change.