Metabolic advantages of spreading the nutrient load: effects of increased meal frequency in non-insulin-dependent diabetes

No Effect of High Eating Frequency Compared with Low Eating Frequency on Appetite and Inflammation Biomarkers: Results from a Randomized Crossover Clinical Trial

BACKGROUND

Eating frequency (EF) focuses on the total number of eating occasions per day and may influence metabolic health.

OBJECTIVES

We sought to examine the effect of high compared with low EF on appetite regulation and inflammatory biomarkers among healthy adults.

METHODS

Data are from a randomized, crossover trial (the Frequency of Eating and Satiety Hormones study). Participants (n = 50) completed 2 isocaloric 21-d study periods of low EF (3 eating occasions/d) and high EF (6 eating occasions/d) in random order with a 14-d washout period in between. Participants were free-living and consumed their own food, using study-directed, structured meal plans with identical foods and total energy in both study periods. On days 1 and 21 of each EF period, fasting blood was collected during in-person clinic visits to assess plasma concentrations of ghrelin, leptin, adiponectin, and high-sensitivity C-reactive protein (hs-CRP). Linear mixed models with EF, diet sequence, and period as fixed effects and participant as random effect were used to estimate the intervention effect. Interaction effects between EF and body fat percentage were examined.

RESULTS

Among the 50 participants who completed the trial, 39 (78%) were women, 30 (60%) were Non-Hispanic White, and 40 (80%) had a body mass index of <25 kg/m2, and the mean age was 32.1 y. The differences between high and low EF in fasting ghrelin (geometric mean difference: 17.76 ng/mL; P = 0.60), leptin (geometric mean difference: 2.09 ng/mL; P = 0.14), adiponectin (geometric mean difference: 381.7 ng/mL; P = 0.32), and hs-CRP (geometric mean difference: -0.018 mg/dL; P = 0.08) were not statistically significant. No significant interaction was observed between EF and body fat percentage on appetite regulation and inflammatory biomarkers.

CONCLUSIONS

No differences was observed in fasting ghrelin, leptin, adiponectin, and hs-CRP comparing high and low EF. Future studies are needed to understand the physiology of EF and appetite as they relate to metabolic health. This trial was registered at clinicaltrials.gov as NCT02392897.

Effects of Diet, Lifestyle, Chrononutrition and Alternative Dietary Interventions on Postprandial Glycemia and Insulin Resistance

As years progress, we are found more often in a postprandial than a postabsorptive state. Chrononutrition is an integral part of metabolism, pancreatic function, and hormone secretion. Eating most calories and carbohydrates at lunch time and early afternoon, avoiding late evening dinner, and keeping consistent number of daily meals and relative times of eating occasions seem to play a pivotal role for postprandial glycemia and insulin sensitivity. Sequence of meals and nutrients also play a significant role, as foods of low density such as vegetables, salads, or soups consumed first, followed by protein and then by starchy foods lead to ameliorated glycemic and insulin responses. There are several dietary schemes available, such as intermittent fasting regimes, which may improve glycemic and insulin responses. Weight loss is important for the treatment of insulin resistance, and it can be achieved by many approaches, such as low-fat, low-carbohydrate, Mediterranean-style diets, etc. Lifestyle interventions with small weight loss (7–10%), 150 min of weekly moderate intensity exercise and behavioral therapy approach can be highly effective in preventing and treating type 2 diabetes. Similarly, decreasing carbohydrates in meals also improves significantly glycemic and insulin responses, but the extent of this reduction should be individualized, patient-centered, and monitored. Alternative foods or ingredients, such as vinegar, yogurt, whey protein, peanuts and tree nuts should also be considered in ameliorating postprandial hyperglycemia and insulin resistance. This review aims to describe the available evidence about the effects of diet, chrononutrition, alternative dietary interventions and exercise on postprandial glycemia and insulin resistance.

Novel trends and concepts in the nutritional management of glycemia in type 2 diabetes mellitus-beyond dietary patterns: a narrative review

A variety of eating patterns are recommended by international guidelines to help people with type 2 diabetes mellitus (T2DM) achieve general health and glycemia goals. Apart from eating patterns, there is evidence that other approaches related to the everyday application of dietary advice, such as meal frequency, breakfast consumption, daily carbohydrate distribution, and order of food consumption during meals, have significant effects on glycemia management. The aims of this review were to examine published diabetes nutrition guidelines concerning specific recommendations with regard to the above approaches, as well as to review evidence from studies that have investigated their effect on glycemia in T2DM. The data suggest that eating breakfast regularly, consuming most carbohydrates at lunch, avoiding large dinners late at night, and applying the carbohydrate-last meal pattern are effective practices towards better nutritional management of T2DM.

Glycemic index of millet based food mix and its effect on pre diabetic subjects

Diet plays an important role in management of diabetes and foods having low glycemic index are gaining more importance as they delay the release of glucose in the blood. It is essential to develop low glycemic food mix from regionally available ingredients for use in daily dietaries. Hence, the present study was undertaken to assess the glycemic index of the traditional recipes prepared from developed millet based food mix and their effect on pre diabetic subjects. The developed millet based food mix had appreciable amount of protein (19.41 g/100 g) and dietary fibre (21.11 g/100 g). The traditional recipes viz., roti, dosa and dumpling (mudde) prepared from developed mix exhibited higher acceptance with good sensory parameters and are comparable to regional preparations. The glycemic index was found to be 37, 48 and 53 for dosa, mudde and roti respectively with a glycemic load of 11.05, 18.43 and 18.09. However, all the three developed products showed the relatively lower glycemic index (< 55) and moderate glycemic load of < 20. Further, dietary intervention on pre diabetic subjects revealed that there was a significant reduction in FBS (120.50 ± 18.73 to 97.81 ± 20.00) and HbA1c (6.14 ± 0.30 to 5.67 ± 0.40) indicating their preferable option in the management of diabetes mellitus.

Validation and Implementation of an Automated Chew Sensor-Based Remote Monitoring Device as Tool for Equine Grazing Research

Field studies characterizing equine grazing activity primarily rely on observational protocols, limiting the quantity and accuracy of collected data. The objectives of this study were to validate an automated chew sensor technology, the EquiWatch System (EWS), for detecting grazing behaviors and to demonstrate potential applications of the EWS in equine grazing research. Eight mature standardbred mares were used in this study. EquiWatch System validation was completed in two phases: grazing time was evaluated in experiment 1 and chew counts in experiment 2. The correlation between visual observations and system-recorded grazing time was high (concordance correlation coefficient [CCC] = 0.997). There was also a high agreement between the sum of manually counted bites and chews and total chew counts reported by the EWS (CCC = 0.979). Following validation, a pilot study was conducted using the EWS to assess feeding behaviors of horses with unrestricted pasture access (PAS) versus horses offered ad libitum hay (HAY). Horses spent more time engaged in feeding behavior on PAS (14.79 ± 0.48 hr/d) than HAY (11.98 ± 0.48 hr/d; P < .0001). Chewing rate also differed by forage (PAS 83.92 ± 1.61; HAY 68.50 ± 1.61 chews/min; P < .0001). However, although the magnitude of these behavioral parameters was influenced by treatment, the underlying 24-hour patterns were largely preserved regardless of forage type. These results demonstrate that the EWS can generate data necessary for characterizing feeding behavior in horses. Future studies implementing this tool could provide a greater understanding of biological, environmental, and nutritive factors driving grazing behavior in horses.

Effect of Short-Term Increase in Meal Frequency on Glucose Metabolism in Individuals with Normal Glucose Tolerance or Impaired Fasting Glucose: A Randomized Crossover Clinical Trial

Effects of meal frequency on blood glucose levels and glucose metabolism were evaluated over 3 days in adult males with normal glucose tolerance (NGT, n = 9) or impaired fasting glucose (IFG, n = 9) in a randomized, crossover comparison study. Subjects were provided with an isocaloric diet 3 times daily (3M) or 9 times daily (9M). Blood glucose was monitored on Day 3 using a continuous glucose monitoring system, and subjects underwent a 75-g oral glucose tolerance test (OGTT) on Day 4. Daytime maximum blood glucose, glucose range, duration of glucose ≥180 mg/dL, and nighttime maximum glucose were significantly lower in the NGT/9M condition than in the NGT/3M condition. Similar findings were observed in the IFG subjects, with a lower daytime and nighttime maximum glucose and glucose range, and a significantly higher daytime minimum glucose in the 9M condition than in the 3M condition. The OGTT results did not differ significantly between NGT/3M and NGT/9M conditions. In contrast, the incremental area under the curve tended to be lower and the maximum plasma glucose concentration was significantly lower in the IFG/9M condition than in the IFG/3M condition. In IFG subjects, the 9M condition significantly improved glucose metabolism compared with the 3M condition. Higher meal frequency may increase glucagon-like peptide 1 secretion and improve insulin secretion.

Eating frequency is inversely associated with BMI, waist circumference and the proportion of body fat in Korean adults when diet quality is high, but not when it is low: analysis of the Fourth Korea National Health and Nutrition Examination Survey (KNHANES IV)

The role of eating frequency (EF) in obesity development has been debated, and few studies have investigated Asian populations. Diet quality might affect the association between EF and obesity. Therefore, we investigated the association between EF and obesity indicators in a representative sample of Korean adults with consideration to diet quality. This cross-sectional study used data of 6951 participants aged 19-93 years (male 49·8 %, female 50·2 %) from the Fourth Korean National Health and Nutrition Examination Survey. EF was assessed using a questionnaire, and diet quality was defined as mean adequacy ratio (MAR). To explore the association between EF and obesity indicators, we used multiple linear regression analyses with and without interaction terms between diet quality and EF. EF was inversely associated with each obesity indicator, including body fat percentage (BF%), BMI and waist circumference (WC), showing a significant linear trend (P<0·001 for BF%, WC and BMI). In addition, the association between EF and each obesity indicator was significantly altered according to diet quality (P value of the interaction term EF×diet quality=0·008 in the regression model for BF%, <0·001 for BMI and 0·043 for WC). In the stratified analyses according to diet quality, EF had a significant inverse association with BF%, WC and BMI in the high diet quality groups, but not in the low diet quality groups. This study suggests that EF is inversely associated with the obesity indicators when diet quality is high, but not when it is low in Korean adults.

Impact of different timing of consuming sweet snack on postprandial glucose excursions in healthy women

AIMS

Our aim was to evaluate the acute effect of eating sweet snacks at different times of day on glycaemic parameters in young women without diabetes.

METHODS

In this randomized controlled three-treatment crossover study, 17 women [(means ± SD) age: 21.2 ± 0.8 years, BMI: 20.7 ± 2.5 kg/m2, HbA_1c: 36 ± 2 mmol/mol (5.1 ± 0.2%)] wore flash (continuous) glucose monitoring systems for 7 days. Each participant consumed identical test meals on days 4, 5 and 6, but consumed sweet snacks (baked cake: 498 kcal; 53.6 g of carbohydrate, 8.0 g of protein, 28.0 g of fat) at 12:30 (post-lunch), 15:30 (mid-afternoon) and 19:30 (post-dinner), respectively, on each of those days. Daily glycaemic parameters on those 3 days of snacking at different times of day were compared within-participant.

RESULTS

The mean amplitude of glycaemic excursions (3.54 ± 0.32 vs. 2.73 ± 0.20 mmol/L; P < 0.05), standard deviation of glucose (1.20 ± 0.11 vs. 0.92 ± 0.07 mmol/L; P < 0.05), incremental area under the curve (IAUC) for glucose at 12:00-07:00 (986 ± 89 vs. 716 ± 88 mmol/L × min; P < 0.05) and IAUC at 07:00-10:00 the next day (141 ± 17 vs. 104 ± 12 mmol/L × min; P < 0.05) when the snack was eaten post-dinner were all significantly higher than with mid-afternoon snacking.

CONCLUSION

Eating sweet snacks post-dinner should be avoided because it worsens glucose excursions as well as postprandial glucose levels after both dinner and the following day's breakfast in young healthy (non-diabetic) women.

Consuming snacks mid-afternoon compared with just after lunch improves mean amplitude of glycaemic excursions in patients with type 2 diabetes: A randomized crossover clinical trial

AIMS

Our aim was to explore the acute effects of consuming snacks at different times on glucose excursions in patients with type 2 diabetes (T2D).

METHODS

Seventeen patients with T2D [means±SD: age 67.4±9.4-years; BMI 23.5±3.1kg/m²; HbA_1c 55±6mmol/mol (7.2±1.0%)] were randomly assigned in this crossover study. Each participant wore a continuous glucose monitoring device for 4 days and consumed identical test meals on the second and third days, comprising breakfast at 0700h, lunch at 1200h and dinner at 1900h. Half the participants consumed 75kcal biscuits at 1230h (just after lunch) on the second day and at 1530h (mid-afternoon) on the third day, while the other half consumed snacks at the same times, but vice versa. Each patient's glucose parameters were compared against baseline for the 2days of snacking at different times of day.

RESULTS

Consuming snacks in the mid-afternoon led to significantly lower mean amplitudes of glycaemic excursions (mean±SEM: 5.19±0.48 vs. 6.90±0.69mmol/L, P<0.01; standard deviation: 1.75±0.17 vs. 2.16±0.21mmol/L, P<0.01) and incremental areas under the curve for glucose after dinner (479±76 vs. 663±104mmol/L per min, P<0.01) compared with snacking just after lunch, whereas mean glucose levels did not differ over the 2days.

CONCLUSION

These results suggest that consuming snacks well separated from lunch may be an effective way to suppress postprandial glucose levels and glycaemic excursions.

The duration of intermittent access to preferred sucrose-rich food affects binge-like intake, fat accumulation, and fasting glucose in male rats

Many people restrict their palatable food intake. In animal models, time-limiting access to palatable foods increases their intake while decreasing intake of less preferred alternatives; negative emotional withdrawal-like behavior is sometimes reported. In drug addiction models, intermittent extended access drives greater changes in use than brief access. When it comes to palatable food, the impact of briefer vs. longer access durations within intermittent access conditions remains unclear. Here, we provided male rats with chow or with weekday access to a preferred, sucrose-rich diet (PREF) (2, 4, or 8 h daily) with chow otherwise available. Despite normal energy intake, all restricted access conditions increased weight gain by 6 weeks and shifted diet acceptance within 1 week. They increased daily and 2-h intake of PREF with individual vulnerability and decreased chow intake. Rats with the briefest access had the greatest binge-like (2-h) intake, did not lose weight on weekends despite undereating chow, and were fattier by 12 weeks. Extended access rats (8 h) showed the greatest daily intake of preferred food and corresponding undereating of chow, slower weight gain when PREF was unavailable, and more variable daily energy intake from week to week. Increased fasting glucose was seen in 2-h and 8-h access rats. During acute withdrawal from PREF to chow diet, restricted access rats showed increased locomotor activity. Thus, intermittent access broadly promoted weight gain, fasting hyperglycemia and psychomotor arousal during early withdrawal. More restricted access promoted greater binge-like intake and fat accumulation, whereas longer access promoted evidence of greater food reward tolerance.

Longitudinal association between eating frequency and hemoglobin A1c and serum lipids in diabetes in the SEARCH for Diabetes in Youth study

BACKGROUND

Few studies have evaluated the prospective association of eating frequency with HbA1c levels and cardiovascular disease risk markers among youth with diabetes.

OBJECTIVE

To examine the 5-year longitudinal association of eating frequency with HbA1c and serum lipid levels among youth with type 1 diabetes (T1D) or type 2 diabetes (T2D).

METHODS

One-thousand and forty-nine youth (≥10-year old) with incident T1D (n = 821) or T2D (n = 228) who participated in the SEARCH for Diabetes in Youth study were included. Eating frequency (≤3, 4-5, or 6-10 times/d) measured at baseline and follow-up visits was related to HbA1c and serum lipid levels measured repeatedly over 5 years.

RESULTS

Increased eating frequency was associated with larger increases in HbA1c among youth T1D. For example, for youth with T1D who ate ≤3 times/d at the outset and ate 6-10 times/d 5 years later, the longitudinal model predicted greater absolute increases in HbA1c (2.77%); whereas for youth with T1D who ate 6-10 times/d at the outset and ate ≤3 times/d 5 years later, the model predicted lesser absolute increases in HbA1c (1.33%). Eating frequency was not associated with changes in serum lipid levels among youth with T1D or T2D.

CONCLUSIONS

Youth with T1D who increased their eating frequency vs those who decreased it had larger increases in HbA1c over 5 years.

Effects of 6 vs 3 eucaloric meal patterns on glycaemic control and satiety in people with impaired glucose tolerance or overt type 2 diabetes: A randomized trial

BACKGROUND/OBJECTIVES

The study aimed to compare the effects of two eucaloric meal patterns (3 vs 6 meals/day) on glycaemic control and satiety in subjects with impaired glucose tolerance and plasma glucose (PG) levels 140-199mg/dL at 120min (IGT-A) or PG levels 140-199mg/dL at 120min and >200mg/dL at 30/60/90min post-oral glucose load on 75-g OGTT (IGT-B), or overt treatment-naïve type 2 diabetes (T2D).

SUBJECTS/METHODS

In this randomized crossover study, subjects with IGT-A (n=15, BMI: 32.4±5.2kg/m²), IGT-B (n=20, BMI: 32.5±5kg/m²) or T2D (n=12, BMI: 32.2±5.2kg/m²) followed a weight-maintenance diet (45% carbohydrates, 20% proteins, 35% fats) in 3 or 6 meals/day (each intervention lasting 12 weeks). Anthropometrics, diet compliance and subjective appetite were assessed every 2 weeks. OGTT and measurements of HbA1c and plasma lipids were performed at the beginning and end of each intervention period.

RESULTS

Body weight and physical activity levels remained stable throughout the study. In T2D, HbA1c and PG at 120min post-OGTT decreased with 6 vs 3 meals (P<0.001 vs P=0.02, respectively). The 6-meal intervention also improved post-OGTT hyperinsulinaemia in IGT-A subjects and hyperglycaemia in IGT-B subjects. In all three groups, subjective hunger and desire to eat were reduced with 6 vs 3 meals/day (P<0.05). There were no differences in HOMA-IR or plasma lipids between interventions.

CONCLUSION

Although weight loss remains the key strategy in hyperglycaemia management, dietary measures such as more frequent and smaller meals may be helpful for those not sufficiently motivated to adhere to calorie-restricted diets. Our study shows that 6 vs 3 meals a day can increase glycaemic control in obese patients with early-stage T2D, and may perhaps improve and/or stabilize postprandial glucose regulation in prediabetes subjects.

Evaluation of the glycemic indices of three commonly eaten mixed meals in Okada, Edo State

People do not generally eat single or individual meals; rather they eat mixed meals, consisting of two or more individual meals. These mixed meals usually have glycemic indices which differ from that of the individual food type. This study was aimed at evaluating the glycemic indices of three commonly consumed mixed meals eaten in Okada; rice and beans (test food 1), rice and plantain (test food 2), beans and plantain (test food 3). Two hundred and forty healthy subjects aged between 18 and 30 participated in this study. They were randomized into three groups of eighty persons each, and fed with the standard food (50 g glucose) on day one and one of the test foods on day two, after an overnight fast. Blood samples were taken at 0, 30, 60, 90, and 120 min after the food had been eaten. The results showed that the Glycemic Index (GI) values for the test foods were high: 86.60 (test food 1), 89.74 (test food 2), 86.93(test food 3). The incremental increase in blood glucose was monitored and calculated for each food and when compared with that of the standard food (glucose), there was significant differences (p < .036) for test food 1 and (p < .068) for test food 3; both at 30 min. At 120 min, no significant differences in blood glucose levels were observed (p > .05). The results from this study indicated that the GI of the mixed meals was affected by the constituent nutrient and the response is also affected by the proportion of each nutrient. Our findings show that the selected test foods (mixed meals) consumed in Okada have high GI values.

Development and validation of the self-administered Falun health instrument (SAFHI) using data from health promoted workplaces in Sweden

AIM

The aim of this study was to develop and to validate the self-administered Falun health instrument. An additional aim was to test its applicability in measuring people's lifestyles linked to health.

METHODS

In 2002, an instrument was constructed containing questions regarding the hazardous use of alcohol, tobacco, unhealthy diets and insufficient physical activity. A pilot study using the instrument was assessed between 2002 and 2006. In Sweden, it was further expanded and tested during the years 2004-2014 among a total of 1295 people.

RESULTS

Face validity was evaluated among colleagues and experts for clarity and completeness resulting in minor adjustments of some questions. With the test-retest method, the self-administered Falun health questionnaire showed a positive and high reproducibility and high compliance. Cronbach's alpha showed a high level of consistency (average 0.86). Factor analysis demonstrated the choice of questions correlated highly to the measured lifestyle.

CONCLUSIONS

This study showed that the self-administered Falun health questionnaire is a valid and reliable instrument, useful for detecting individuals at risk of developing diseases that are related to individual choice of lifestyle.

Postprandial changes in cardiometabolic disease risk in young Chinese men following isocaloric high or low protein diets, stratified by either high or low meal frequency - a randomized controlled crossover trial

BACKGROUND

Cardio-Metabolic Disease (CMD) is the leading cause of death globally and particularly in Asia. Postprandial elevation of glycaemia, insulinaemia, triglyceridaemia are associated with an increased risk of CMD. While studies have shown that higher protein intake or increased meal frequency may benefit postprandial metabolism, their combined effect has rarely been investigated using composite mixed meals. We therefore examined the combined effects of increasing meal frequency (2-large vs 6-smaller meals), with high or low-protein (40 % vs 10 % energy from protein respectively) isocaloric mixed meals on a range of postprandial CMD risk markers.

METHODS

In a randomized crossover study, 10 healthy Chinese males (Age: 29 ± 7 years; BMI: 21.9 ± 1.7 kg/m(2)) underwent 4 dietary treatments: CON-2 (2 large Low-Protein meals), CON-6 (6 Small Low-Protein meals), PRO-2 (2 Large High-Protein meals) and PRO-6 (6 Small High-Protein meals). Subjects wore a continuous glucose monitor (CGM) and venous blood samples were obtained at baseline and at regular intervals for 8.5 h to monitor postprandial changes in glucose, insulin, triglycerides and high sensitivity C-reactive protein (hsCRP). Blood pressure was measured at regular intervals pre- and post- meal consumption. Urine was collected to measure excretion of creatinine and F2-isoprostanes and its metabolites over the 8.5 h postprandial period.

RESULTS

The high-protein meals, irrespective of meal frequency were beneficial for glycaemic health since glucose incremental area under the curve (iAUC) for PRO-2 (185 ± 166 mmol.min.L(-1)) and PRO-6 (214 ± 188 mmol.min.L(-1)) were 66 and 60 % lower respectively (both p < 0.05), compared with CON-2 (536 ± 290 mmol.min.L(-1)). The iAUC for insulin was the lowest for PRO-6 (13.7 ± 7.1 U.min.L(-1)) as compared with CON-2 (28.4 ± 15.6 U.min.L(-)1), p < 0.001. There were no significant differences in postprandial responses in other measurements between the dietary treatments.

CONCLUSIONS

The consumption of composite meals with higher protein content, irrespective of meal frequency appears to be beneficial for postprandial glycemic and insulinemic responses in young, healthy Chinese males. Implications of this study may be useful in the Asian context where the consumption of high glycemic index, carbohydrate meals is prevalent.

TRIAL REGISTRATION

NCT02529228 .

Effects of meal frequency on weight loss and body composition: a meta-analysis

It has been hypothesized that eating small, frequent meals enhances fat loss and helps to achieve better weight maintenance. Several observational studies lend support to this hypothesis, with an inverse relationship noted between the frequency of eating and adiposity. The purpose of this narrative review is to present and discuss a meta-analysis with regression that evaluated experimental research on meal frequency with respect to changes in fat mass and lean mass. A total of 15 studies were identified that investigated meal frequency in accordance with the criteria outlined. Feeding frequency was positively associated with reductions in fat mass and body fat percentage as well as an increase in fat-free mass. However, sensitivity analysis of the data showed that the positive findings were the product of a single study, casting doubt as to whether more frequent meals confer beneficial effects on body composition. In conclusion, although the initial results of this meta-analysis suggest a potential benefit of increased feeding frequencies for enhancing body composition, these findings need to be interpreted with circumspection.

Metabolic profile and psychological variables after bariatric surgery: association with weight outcomes

PURPOSE

This study aims to examine associations between metabolic profile and psychological variables in post-bariatric patients and to investigate if metabolic and psychological variables, namely high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), glycated hemoglobin (HbA 1c), impulsivity, psychological distress, depressive and eating disorder symptoms are independently associated with percentage of excess weight loss (%EWL) after bariatric surgery.

METHODS

One hundred and fifty bariatric patients (BMI = 33.04 ± 5.8 kg/m(2)) who underwent to bariatric surgery for more than 28.63 ± 4.9 months were assessed through a clinical interview, a set of self-report measures and venous blood samples. Pearson's correlations were used to assess correlations between %EWL, metabolic and psychological variables. Multiple linear regression was conducted to investigate which metabolic and psychological variables were independently associated with %EWL, while controlling for type of surgery.

RESULTS

Higher TG blood levels were associated with higher disordered eating, psychological distress and depression scores. HDL-C was associated with higher depression scores. Both metabolic and psychological variables were associated with %EWL. Regression analyses showed that, controlling for type of surgery, higher % EWL is significantly and independently associated with less disordered eating symptoms and lower TG and HbA_1c blood concentrations (R (2) aj = 0.383, F (4, 82) = 14.34, p < 0.000).

CONCLUSION

An association between metabolic and psychological variables, particularly concerning TG blood levels, disordered eating and psychological distress/depression was found. Only higher levels of disordered eating, TG and HbA_1c showed and independent correlation with less weight loss. Targeting maladaptive eating behaviors may be a reasonable strategy to avoid weight regain and optimize health status post-operatively.

Medication Use and Metabolic Syndrome Among Overweight/Obese Patients With and Without Binge-Eating Disorder in a Primary Care Sample

OBJECTIVE

To examine metabolic factors among overweight/obese individuals with binge-eating disorder (BED) and non-binge-eating overweight/obese (NBO) patients recruited from primary care and to examine and compare medication use by these groups.

METHOD

Participants were 102 adults recruited for a weight loss study within primary care centers who were assessed for BED (28 [38%] met DSM-5 BED criteria). Participants completed a medication log, had physiologic measurements taken, and were evaluated for the presence of metabolic syndrome using 2 methods. Data were collected between February 2012 and October 2012.

RESULTS

The BED group had a higher mean body mass index (BMI), a higher pulse, and a larger waist circumference than the NBO group. Of the sample, 65% reported current medication use (prescription and/or over-the-counter medications): 19.6% took 3 to 4 medications and 15.7% took ≥ 5 medications. Aside from vitamin and over-the-counter allergy pill use, there were no differences in medication use between BED and NBO patients. Full metabolic syndrome (≥ 3 criteria met) was present in 31.5% of the sample when using objective measurement alone, and 39.1% of the sample when defined by objective measurement and pharmacologic management. No significant differences were observed regardless of definition.

CONCLUSIONS

Despite higher BMI, pulse, and waist circumference, the current sample of BED patients in primary care did not present with poorer metabolic health than NBO patients.

Frequency and Circadian Timing of Eating May Influence Biomarkers of Inflammation and Insulin Resistance Associated with Breast Cancer Risk

Emerging evidence suggests that there is interplay between the frequency and circadian timing of eating and metabolic health. We examined the associations of eating frequency and timing with metabolic and inflammatory biomarkers putatively associated with breast cancer risk in women participating in the National Health and Nutrition Examination 2009-2010 Survey. Eating frequency and timing variables were calculated from 24-hour food records and included (1) proportion of calories consumed in the evening (5 pm-midnight), (2) number of eating episodes per day, and (3) nighttime fasting duration. Linear regression models examined each eating frequency and timing exposure variable with C-reactive protein (CRP) concentrations and the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR). Each 10 percent increase in the proportion of calories consumed in the evening was associated with a 3 percent increase in CRP. Conversely, eating one additional meal or snack per day was associated with an 8 percent reduction in CRP. There was a significant interaction between proportion of calories consumed in the evening and fasting duration with CRP (p = 0.02). A longer nighttime fasting duration was associated with an 8 percent lower CRP only among women who ate less than 30% of their total daily calories in the evening (p = 0.01). None of the eating frequency and timing variables were significantly associated with HOMA-IR. These findings suggest that eating more frequently, reducing evening energy intake, and fasting for longer nightly intervals may lower systemic inflammation and subsequently reduce breast cancer risk. Randomized trials are needed to validate these associations.

Metabolic characterization of adults with binge eating in the general population: the Framingham Heart Study

OBJECTIVE

To describe the metabolic profile of individuals with objective binge eating (OBE) and to evaluate whether associations between OBE and metabolic risk factors are mediated by body mass index (BMI).

METHODS

Participants from the Framingham Heart Study, Third Generation and Omni 2 cohorts (n = 3,551, 53.1% women, mean age 46.4 years) were screened for binge eating. Multivariable-adjusted regression models to examine the associations of OBE with metabolic risk factors were used.

RESULTS

The prevalence of OBE was 4.8% in women and 4.9% in men. Compared to non-binge eating, OBE was associated with higher odds of hypertension (OR 1.85, 95% CI 1.32-2.60), hypertriglyceridemia (OR 1.42, 95% CI 1.01-2.01), low HDL (OR 1.70, 95% CI 1.18-2.44), insulin resistance (OR 3.18, 95% CI 2.25-4.50) and metabolic syndrome (OR 2.75, 95% CI 1.94-3.90). Fasting glucose was 7.2 mg dl(-1) higher in those with OBE (P = 0.0001). Individuals with OBE had more visceral, subcutaneous and liver fat. Most of these associations were attenuated with adjustment for BMI, with the exception of fasting glucose.

CONCLUSIONS

Binge eating is associated with a high burden of metabolic risk factors. Much of the associated risk appears to be mediated by BMI, with the exception of fasting glucose.

Alteration of postprandial glucose and insulin concentrations with meal frequency and composition

A frequent eating pattern may alter glycaemic control and augment postprandial insulin concentrations in some individuals due to the truncation of the previous postprandial period by a subsequent meal. The present study examined glucose, insulin, C-peptide and glucose-dependent insulinotropic peptide (GIP) responses in obese individuals when meals were ingested in a high-frequency pattern (every 2 h, 6M) or in a low-frequency pattern (every 4 h, 3M) over 12 h. It also examined these postprandial responses to high-frequency, high-protein meals (6MHP). In total, thirteen obese subjects completed three 12 h study days during which they consumed 6276 kJ (1500 kcal): (1) 3M - 15 % protein and 65 % carbohydrate; (2) 6M - 15 % protein and 65 % carbohydrate; (3) 6MHP - 45 % protein and 35 % carbohydrate. Blood samples were collected every 10 min and analysed for glucose, insulin, C-peptide and GIP. Insulin total AUC (tAUC) and peak insulin concentrations (P< 0·05) were higher in the 3M condition than in the 6M condition, but there were no differences in glucose tAUC between the conditions. The 6MHP regimen (glucose: 3569 (se 83) mmol/l × min (64·3 (se 1·5) g/dl × min), insulin: 1·577 (se 0·146) pmol/l (22·7 (se 2·1) μIU/dl) for 12 h) lowered glucose and insulin excursions more so over 12 h than either the 3M regimen (glucose: 3913 (se 78) mmol/l × min (70·5 (se 1·4) g/dl × min), insulin: 2·195 (se 0·146) pmol/l × min (31·6 (se 2·1) μIU/dl × min) for 12 h) or the 6M regimen (glucose: 3902 (se 83) mmol/l × min (70·3 (se 1·5) g/dl × min), insulin: 1·861 (se 0·174) pmol/l × min (26·8 (se 2·5) μIU/dl × min) for 12 h; P< 0·01). Insulin secretion, GIP concentrations and the glucose:insulin ratio were not altered by meal frequency or composition. In obese subjects, ingestion of meals in a low-frequency pattern does not alter glucose tAUC, but increases postprandial insulin responses. The substitution of carbohydrates with protein in a frequent meal pattern results in tighter glycaemic control and reduced postprandial insulin responses.

Eating frequency is inversely associated with blood pressure and hypertension in Korean adults: analysis of the Third Korean National Health and Nutrition Examination Survey

BACKGROUND/OBJECTIVES

A lower eating frequency (EF) has been suggested to be important in the development of cardiovascular risk factors such as obesity and hyperlipidemia. However, the association between EF and blood pressure (BP) remains unclear.

SUBJECTS/METHODS

The aim of this study was to explore the association of EF with BP and hypertension after adjusting for confounding variables, including body mass index (BMI) and waist circumference (WC). This cross-sectional study used data from the Third Korean National Health and Nutrition Examination Survey. A total of 4625 subjects aged ≥ 19 years were included. To explore the association of EF with BP and hypertension, we performed multiple linear regression analyses and multiple logistic regression analyses for survey design, respectively.

RESULTS

EF was inversely associated with systolic BP (SBP) and diastolic BP (DBP). As EF increased from ≤ 2 to 3, 4 and ≥ 5 times per day, estimated adjusted means of both SBP and DBP decreased, showing a significant linear trend independent of obesity (SBP: 120.66, 120.23, 119.18 and 117.92 mm Hg, respectively; P<0.001; DBP: 78.36, 77.78, 77.25 and 76.50 mm Hg, respectively; P=0.004). The inverse association between EF and hypertension was gradually attenuated and significant after adjustment for confounding variables including BMI and WC (P=0.040).

CONCLUSIONS

This study suggests that lower EF is significantly associated with higher BP, which may be partially mediated by the effect of central obesity. Further prospective studies are needed to verify this causal relationship.

Prevalence and energy intake from snacking in Brazil: analysis of the first nationwide individual survey

BACKGROUND/OBJECTIVES

Snacking has increased globally. We examine snacking patterns and common snack foods in Brazil.

SUBJECTS/METHODS

Data from the first of two non-consecutive food diaries from 34,003 individuals (aged ≥ 10 years) in the first Brazillian nationally representative dietary survey (2008-2009) were used. Meals were defined as the largest (kcal) eating event reported during select times of the day (Breakfast, 0600-1000 hours; Lunch, 1200-1500 hours; Dinner, 1800-2100 hours); all other eating occasions were considered snacks. We estimate daily energy intake, percentage of persons consuming snacks, number of daily snacks and per capita and per consumer energy from snacks (kcal/day, kcal/snack and % of daily energy from snacks).

RESULTS

In all, 74% of Brazilians (≥ 10 years) snacked, reporting an average 1.6 snacks/day. Also, 23% of the sample were heavy snackers (≥ 3 snacks/day). Snacking accounted for 21% of daily energy intake in the full sample but 35.5% among heavy snackers. Compared with non-snackers (1548 kcal/day), light (1-2 snacks/day) and heavy snackers consumed more daily energy (1929 and 2334 kcal/day, respectively). Taking into account time of day, the largest percentage of persons reported afternoon/early evening snacking (1501-1759 hours, 47.7%). Sweetened coffee and tea, sweets and desserts, fruit, sugar-sweetened beverages, and high-calorie salgados (fried/baked dough with meat/cheese/vegetable) were the top five most commonly consumed snacks. Differences were observed by age groups. Trends in commercial sales were observed, especially for sugar-sweetened beverages.

CONCLUSIONS

Many commonly consumed snack foods in Brazil are classified, in the US, as being high in solid fats and added sugars. The public health impact of snacking in Brazil requires further exploration.

Glycaemic index methodology

The glycaemic index (GI) concept was originally introduced to classify different sources of carbohydrate (CHO)-rich foods, usually having an energy content of >80 % from CHO, to their effect on post-meal glycaemia. It was assumed to apply to foods that primarily deliver available CHO, causing hyperglycaemia. Low-GI foods were classified as being digested and absorbed slowly and high-GI foods as being rapidly digested and absorbed, resulting in different glycaemic responses. Low-GI foods were found to induce benefits on certain risk factors for CVD and diabetes. Accordingly it has been proposed that GI classification of foods and drinks could be useful to help consumers make 'healthy food choices' within specific food groups. Classification of foods according to their impact on blood glucose responses requires a standardised way of measuring such responses. The present review discusses the most relevant methodological considerations and highlights specific recommendations regarding number of subjects, sex, subject status, inclusion and exclusion criteria, pre-test conditions, CHO test dose, blood sampling procedures, sampling times, test randomisation and calculation of glycaemic response area under the curve. All together, these technical recommendations will help to implement or reinforce measurement of GI in laboratories and help to ensure quality of results. Since there is current international interest in alternative ways of expressing glycaemic responses to foods, some of these methods are discussed.

Metabolic syndrome in obese men and women with binge eating disorder: developmental trajectories of eating and weight-related behaviors

Metabolic syndrome (MetSyn), characterized by vascular symptoms, is strongly correlated with obesity, weight-related medical diseases, and mortality and has increased commensurately with secular increases in obesity in the United States. Little is known about the distribution of MetSyn in obese patients with binge eating disorder (BED) or its associations with different developmental trajectories of dieting, binge eating, and obesity problems. Furthermore, inconsistencies in the limited data necessitate elucidation. This study examined the frequency and correlates of MetSyn in a consecutive series of 148 treatment-seeking obese men and women with BED assessed with structured clinical interviews. Almost half of the participants met the criteria for MetSyn. Participants with MetSyn did not differ from those without MetSyn on demographic variables or disordered eating psychopathology. However, our findings suggest that MetSyn is associated with a distinct developmental trajectory, specifically a later age at BED onset and shorter BED duration. Although the findings from this study shed some light on MetSyn and its associations with developmental trajectories of eating and weight-related behaviors, notable inconsistencies characterize the limited literature. Prospective studies are needed to examine causal connections in the development of the MetSyn in relation to disordered eating in addition to excess weight.

The effect of a diet education with six iso-caloric meals on the body weight and blood glucose of diabetes type 2 patients

The treatment of Diabetes should not only be sought through drug administration; diet is also a part of its treatment. The aim of this study was to determine the effect of a diet with six meals having equal calories on the body weight and blood glucose on diabetes type 2 patients. This research is an Experimental study conducted in 2009 on 181 patients with diabetes. The patients visited the IDSF (Iranian Diabetes Society of Fars) weekly and the patients to be studied were randomly divided into two groups of 85 and 96 patients, respectively. The participants were repeatedly requested to consume their calculated calorie in six equal parts. The average age in the Experimental and Control groups were 51.2 ± 13.3 and 53.1 ± 9.4, respectively. The mean body weight and fasting blood glucose at the beginning of the study in Experimental and Control groups were 66.3 ± 9.4 and 69.1 ± 11.1 kg, 198.9 ± 35.1, and 199.8 ± 39.1 mg.dL-1, respectively. At the end of the study, however, the values were 63.5 ± 7.5 and 66.98 ± 9 kg, 139.5 ± 34.6 and 164.2 ± 22.1 mg.dL-1, respectively. Only the mean fasting blood glucose at the end of the study revealed a significant difference (p-value = 0.001). The results show that educating those afflicted with Diabetes Type 2 aiming at changing their diet can greatly help them manage their blood glucose.

Metabolic syndrome in obese patients with binge-eating disorder in primary care clinics: a cross-sectional study

BACKGROUND

The distribution and nature of metabolic syndrome in obese patients with binge-eating disorder (BED) are largely unknown and require investigation, particularly in general internal medicine settings. The objectives of this study were to (1) examine the frequency of metabolic syndrome and (2) explore its eating- and weight-related correlates in obese patients with BED.

METHOD

This was a cross-sectional analysis of 81 consecutive treatment-seeking obese (body mass index ≥ 30 kg/m(2)) patients (21 men, 60 women) who met DSM-IV-TR research criteria for BED (either subthreshold criteria: ≥ 1 binge weekly, n = 19 or full criteria: ≥ 2 binges weekly, n = 62). Participants were from 2 primary care facilities in a large university-based medical center in an urban setting. Patients with and without metabolic syndrome were compared on demographic features and current and historical eating- and weight-related variables. Data were collected from December 2007 through March 2009.

RESULTS

Forty-three percent of patients met criteria for metabolic syndrome. A significantly higher proportion of men (66%) than women (35%) met criteria for metabolic syndrome (P = .012). Patients with versus without metabolic syndrome did not differ significantly in ethnicity or body mass index. Patients with versus without metabolic syndrome did not differ significantly in binge-eating frequency, severity of eating disorder psychopathology, or depression. Analyses of covariance controlling for gender revealed that patients without metabolic syndrome started dieting at a significantly younger age (P = .037), spent more of their adult lives dieting (P = .017), and reported more current dietary restriction (P = .018) than patients with metabolic syndrome.

CONCLUSIONS

Metabolic syndrome is common in obese patients with BED in primary care settings and is associated with fewer dieting behaviors. These findings suggest that certain lifestyle behaviors, such as increased dietary restriction, may be potential targets for intervention with metabolic syndrome.

Potentiation of the early-phase insulin response by a prior meal contributes to the second-meal phenomenon in type 2 diabetes

Improved glucose tolerance following a sequential meal is known as the second-meal phenomenon. We aimed to investigate its extent and underlying mechanisms in patients with type 2 diabetes. Metabolic responses after lunch in 12 diabetic patients were compared on two separate days: one with (Day BL) and another without (Day FL) breakfast. The responses of hormones were calculated by the incremental area under the curve (iAUC) values for 180 min after each meal. Indexes of early-phase insulin secretion were assessed, and β-cell function was estimated by mathematical modeling. [iAUC(glucose(180-360 min))] was significantly lower on Day BL than on Day FL (181 ± 43 vs. 472 ± 29 mmol·liter(-1)·min, P = 0.0005). The magnitude of the The second-meal phenomenon [iAUC(glucose(180-360 min)) on Day BL/Day FL] was 35 ± 9%. The peak levels of insulin and C-peptide were attained 45 min earlier after the second meal than after the first meal. iAUC(glucose(180-360 min)) correlated negatively with iAUC(insulin(180-210 min)) (r = -0.443, P = 0.0300), insulinogenic index (r = -0.769, P < 0.0001), acute C-peptide response (r = -0.596, P = 0.0021), and potentiation factor [i.e., potentiation effect on insulin secretion] ratio (180-360)/(0-20) (r = -0.559, P = 0.0045), while correlated positively with free fatty acid level before lunch (r = 0.679, P = 0.0003). The second-meal phenomenon was evident in patients with type 2 diabetes. Potentiation of the early-phase insulin response by a prior meal contributes to this phenomenon in type 2 diabetes.

Staggered meal consumption facilitates appetite control without affecting postprandial energy intake

Meal pattern may influence hormone and appetite dynamics and food intake. The objective of the study was to determine the effects of staggered compared with nonstaggered meal consumption on hormone and appetite dynamics, food reward (i.e. "liking," "wanting"), and subsequent energy intake. The study was conducted in a randomized cross-over design. Participants (n = 38, age = 24 ± 6 y, BMI = 25.0 ± 3.1 kg/m(2)) came to the university twice for consumption of a 4-course lunch (40% of the daily energy requirements) in 0.5 h (nonstaggered) or in 2 h with 3 within-meal pauses (staggered) followed by ad libitum food intake. Throughout the test sessions, glucagon-like peptide (GLP)-1, peptide tyrosine-tyrosine (PYY(3-36)), ghrelin, appetite, and food reward were measured. In the staggered compared with nonstaggered meal condition, peak values of GLP-1, PYY(3-36), and satiety were lower and time to peak values were higher (P < 0.02); the nadir value of hunger was higher, and time to nadir values of ghrelin and hunger were higher (P < 0.0001). Prior to ad libitum food intake, GLP-1 concentrations and satiety ratings were greater, ghrelin concentrations and hunger ratings were smaller, and food "wanting" was less in the staggered compared with nonstaggered meal condition (P < 0.05). However, this did not affect ad libitum energy intake (1.7 ± 0.3 vs. 1.9 ± 0.2 MJ). In conclusion, staggered compared with nonstaggered meal consumption induces less pronounced hormone and appetite dynamics. Moreover, it results in higher final GLP-1 concentrations and satiety ratings, lower ghrelin concentrations and hunger ratings, and lower food "wanting" prior to ad libitum food intake. However, this was not translated into lower energy intake.

Progesterone increases skeletal muscle mitochondrial H2O2 emission in nonmenopausal women

The luteal phase of the female menstrual cycle is associated with both 1) elevated serum progesterone (P4) and estradiol (E2), and 2) reduced insulin sensitivity. Recently, we demonstrated a link between skeletal muscle mitochondrial H(2)O(2) emission (mE(H2O2)) and insulin resistance. To determine whether serum levels of P4 and/or E(2) are related to mitochondrial function, mE(H2O2) and respiratory O(2) flux (Jo(2)) were measured in permeabilized myofibers from insulin-sensitive (IS, n = 24) and -resistant (IR, n = 8) nonmenopausal women (IR = HOMA-IR > 3.6). Succinate-supported mE(H2O2) was more than 50% greater in the IR vs. IS women (P < 0.05). Interestingly, serum P4 correlated positively with succinate-supported mE(H2O2) (r = 0. 53, P < 0.01). To determine whether P4 or E2 directly affect mitochondrial function, saponin-permeabilized vastus lateralis myofibers biopsied from five nonmenopausal women in the early follicular phase were incubated in P4 (60 nM), E2 (1.4 nM), or both. P4 alone inhibited state 3 Jo(2), supported by multisubstrate combination (P < 0.01). However, E2 alone or in combination with P4 had no effect on Jo(2). In contrast, during state 4 respiration, supported by succinate and glycerophosphate, mE(H2O2) was increased with P4 alone or in combination with E2 (P < 0.01). The results suggest that 1) P4 increases mE(H2O2) with or without E2; 2) P4 alone inhibits Jo(2) but not when E2 is present; and 3) P4 is related to the mE(H2O2) previously linked to skeletal muscle insulin resistance.

Contemporary nutritional transition: determinants of diet and its impact on body composition

The world has experienced a marked shift in the global BMI distribution towards reduced undernutrition and increased obesity. The collision between human biology, shaped over the millennia and modern technology, globalization, government policies and food industry practices have worked to create far-reaching energy imbalance across the globe. A prime example is the clash between our drinking habits and our biology. The shift from water and breast milk as the only beverages available, to a vast array of caloric beverages was very rapid, shaped both by our tastes and aggressive marketing of the beverage industry. Our biology, shaped over millennia by daily consumption of water and seasonal availability of food, was not ready to compensate for the liquid energies. Other dietary changes were similarly significant, particularly the shift towards increased frequency of eating and larger portions. The roles of the food and beverage production, distribution and marketing sectors in not only shaping our diet but also accelerating these changes must be understood. Apart from the role of beverages, there is much less consensus about the role of various components of our diet in energy imbalance. Understanding the determinants of change in the key components of our diet through an array of research provides insights into some of the options we face in attempting to attain a great balance between energy intake and expenditures while creating an overall healthier dietary pattern. A few countries are systematically addressing the causes of poor dietary and physical activity patterns and high energy imbalance.

Chronobiological aspects of food intake and metabolism and their relevance on energy balance and weight regulation

Overweight and obesity are the result of a chronic positive energy balance, and therefore the only effective therapies are a diet which, on the long term, provides lower calories than the daily expended energy and exercise. Because nearly every physiological and biochemical function of the body shows circadian variations it can be suggested that also different chronobiological aspects of food intake, like time of day, meal frequency and regularity, and also circadian desynchronizations like in shift work may affect energy metabolism and weight regulation. The aim of this review is therefore to summarize and discuss studies that have addressed these issues in the past and to also provide an overview about circadian variations of selected aspects of metabolism, gut physiology and also factors that may influence overall energy regulation. The results show that a chronic desynchronization of the circadian system like in shift work and also sleep deprivation can favour the development of obesity. Also, regarding energy balance, a higher meal frequency and regular eating pattern seem to be more advantageous than taking the meals irregularly and seldom. Additional studies are required to conclude whether time of day-dependent food intake significantly influences weight regulation in humans.

Effect of oral sebacic Acid on postprandial glycemia, insulinemia, and glucose rate of appearance in type 2 diabetes

OBJECTIVE

Dicarboxylic acids are natural products with the potential of being an alternate dietary source of energy. We aimed to evaluate the effect of sebacic acid (a 10-carbon dicarboxylic acid; C10) ingestion on postprandial glycemia and glucose rate of appearance (Ra) in healthy and type 2 diabetic subjects. Furthermore, the effect of C10 on insulin-mediated glucose uptake and on GLUT4 expression was assessed in L6 muscle cells in vitro.

RESEARCH DESIGN AND METHODS

Subjects ingested a mixed meal (50% carbohydrates, 15% proteins, and 35% lipids) containing 0 g (control) or 10 g C10 in addition to the meal or 23 g C10 as a substitute of fats.

RESULTS

In type 2 diabetic subjects, the incremental glucose area under the curve (AUC) decreased by 42% (P<0.05) and 70% (P<0.05) in the 10 g C10 and 23 g C10 groups, respectively. At the largest amounts used, C10 reduced the glucose AUC in healthy volunteers also. When fats were substituted with 23 g C10, AUC of Ra was significantly reduced on the order of 18% (P<0.05) in both healthy and diabetic subjects. The insulin-dependent glucose uptake by L6 cells was increased in the presence of C10 (38.7±10.3 vs. 11.4±5.4%; P=0.026). This increase was associated with a 1.7-fold raise of GLUT4.

CONCLUSIONS

Sebacic acid significantly reduced hyperglycemia after a meal in type 2 diabetic subjects. This beneficial effect was associated with a reduction in glucose Ra, probably due to lowered hepatic glucose output and increased peripheral glucose disposal.

Dietary hyperglycemia, glycemic index and metabolic retinal diseases

The glycemic index (GI) indicates how fast blood glucose is raised after consuming a carbohydrate-containing food. Human metabolic studies indicate that GI is related to patho-physiological responses after meals. Compared with a low-GI meal, a high-GI meal is characterized with hyperglycemia during the early postprandial stage (0-2h) and a compensatory hyperlipidemia associated with counter-regulatory hormone responses during late postprandial stage (4-6h). Over the past three decades, several human health disorders have been related to GI. The strongest relationship suggests that consuming low-GI foods prevents diabetic complications. Diabetic retinopathy (DR) is a complication of diabetes. In this aspect, GI appears to be useful as a practical guideline to help diabetic people choose foods. Abundant epidemiological evidence also indicates positive associations between GI and risk for type 2 diabetes, cardiovascular disease, and more recently, age-related macular degeneration (AMD) in people without diabetes. Although data from randomized controlled intervention trials are scanty, these observations are strongly supported by evolving molecular mechanisms which explain the pathogenesis of hyperglycemia. This wide range of evidence implies that dietary hyperglycemia is etiologically related to human aging and diseases, including DR and AMD. In this context, these diseases can be considered as metabolic retinal diseases. Molecular theories that explain hyperglycemic pathogenesis involve a mitochondria-associated pathway and four glycolysis-associated pathways, including advanced glycation end products formation, protein kinase C activation, polyol pathway, and hexosamine pathway. While the four glycolysis-associated pathways appear to be universal for both normoxic and hypoxic conditions, the mitochondria-associated mechanism appears to be most relevant to the hyperglycemic, normoxic pathogenesis. For diseases that affect tissues with highly active metabolism and that frequently face challenge from low oxygen tension, such as retina in which metabolism is determined by both glucose and oxygen homeostases, these theories appear to be insufficient. Several lines of evidence indicate that the retina is particularly vulnerable when hypoxia coincides with hyperglycemia. We propose a novel hyperglycemic, hypoxia-inducible factor (HIF) pathway, to complement the current theories regarding hyperglycemic pathogenesis. HIF is a transcription complex that responds to decrease oxygen in the cellular environment. In addition to playing a significant role in the regulation of glucose metabolism, under hyperglycemia HIF has been shown to increase the expression of HIF-inducible genes, such as vascular endothelial growth factor (VEGF) leading to angiogenesis. To this extent, we suggest that HIF can also be described as a hyperglycemia-inducible factor. In summary, while management of dietary GI appears to be an effective intervention for the prevention of metabolic diseases, specifically AMD and DR, more interventional data is needed to evaluate the efficacy of GI management. There is an urgent need to develop reliable biomarkers of exposure, surrogate endpoints, as well as susceptibility for GI. These insights would also be helpful in deciphering the detailed hyperglycemia-related biochemical mechanisms for the development of new therapeutic agents.

Does hunger and satiety drive eating anymore? Increasing eating occasions and decreasing time between eating occasions in the United States

BACKGROUND

The design of dietary, metabolic, and intervention studies should reflect the meal patterning of free-living individuals, but this design has not been systematically reviewed recently.

OBJECTIVE

Our objective was to examine meal-patterning trends [meals and snacks, termed eating occasions (EOs)] in a sample of US children and adults.

DESIGN

This was a nationally representative cross-sectional study of US data sets from 1977 to 1978, 1994 to 1998, and 2003 to 2006 in 28,404 children (2-18 y of age) and 36,846 adults (> or = 19 y of age). The main outcomes of interest included the number and size (energy/d) of meal and snack EOs, the composition (food or beverage) of each EO, and the time interval between each EO.

RESULTS

The number of EOs increased over the previous 30 y among all ages. For adults and children, the change in the number of EOs from 1977 to 2006 was greatest for those in the 75th and 90th percentiles, although the mean number increased across all percentiles. Energy intake, particularly from snacking, increased for both groups in all percentiles of the distribution. The time between EOs decreased by 1 h for adults and children (to 3.0 and 3.5 h in 2003-2006, respectively). Overwhelmingly, meals consisted of both food and beverages, but the percentage of snacking occasions that consisted of beverages only increased considerably among children.

CONCLUSIONS

US children and adults are consuming foods more frequently throughout the day than they did 30 y ago. Researchers undertaking future clinical, preload, and related food studies need to consider these marked shifts as they attempt to design their research to fit the reality of the eating patterns of free-living individuals.

Association between eating frequency, weight, and health

There is speculation amongst health professionals, the media, and the public regarding eating frequency (EF) and its impact on weight and health. Nutritional weight-loss and -maintenance interventions of longer than 1 week's duration were reviewed for associations between EF and weight and health. Of the 176 studies identified, 25 relevant studies matched the criteria and only 10 of these were weight-loss interventions. Generally, sample sizes were small, interventions were short-term, and a wide array of definitions was used to define an eating occasion. Several key outcomes such as physical activity, adherence to assigned EF, and hunger were often not measured. The limited evidence available suggests there is no association between EF and weight or health in either weight-loss or -maintenance interventions, with a possible inverse association between EF and lipids in weight-maintenance interventions. Longer term, larger studies that include important weight and health outcomes are needed.

Comparison of hormonal and metabolic markers after a high-fat, Western meal versus a low-fat, high-fiber meal in women with polycystic ovary syndrome

OBJECTIVE

To determine the effect of meal composition on postprandial T levels in women with polycystic ovary syndrome (PCOS).

DESIGN

Randomized, crossover design.

SETTING

Academic research center.

PATIENT(S)

Fifteen women with PCOS.

INTERVENTION(S)

We evaluated changes in T, sex hormone binding globulin (SHBG), DHEAS, cortisol, glucose, and insulin for 6 hours after a high-fat, Western meal (HIFAT) (62% fat, 24% carbohydrate, 1 g fiber) and an isocaloric low-fat, high-fiber meal (HIFIB) (6% fat, 81% carbohydrate, 27 g fiber).

MAIN OUTCOME MEASURE(S)

Change in T levels.

RESULT(S)

Testosterone decreased 27% within 2 hours after both meals. However, T remained below premeal values for 4 hours after the HIFIB meal and 6 hours after the HIFAT meal. Insulin was twofold higher for 2 hours after the HIFIB meal compared with the HIFAT meal. Glucose was higher for 1 hour after the HIFIB meal compared with the HIFAT meal. DHEAS decreased 8%-10% within 2-3 hours after both meals, then increased during the remainder of the study period. Cortisol decreased during the 6-hour period after both meals.

CONCLUSIONS

Diet plays a role in the regulation of T levels in women with PCOS. Further studies are needed to determine the role of diet composition in the treatment of PCOS.

Effect of carbohydrate distribution on postprandial glucose peaks with the use of continuous glucose monitoring in type 2 diabetes

BACKGROUND

Large postprandial glucose peaks are associated with increased risk of diabetic complications and cardiovascular disease.

OBJECTIVE

We investigated the effect of carbohydrate distribution on postprandial glucose peaks with continuous blood glucose monitoring (CGMS), when consuming a moderate carbohydrate diet in energy balance in subjects with type 2 diabetes.

DESIGN

Twenty-three subjects with type 2 diabetes were randomly assigned to each of four 3-d interventions in a crossover design with a 4-d washout period. Identical foods were provided for each treatment with a ratio of total carbohydrate to protein to fat of 40%:34%:26% but differing in carbohydrate content at each meal: even distribution (CARB-E; approximately 70 g carbohydrate), breakfast (CARB-B), lunch (CARB-L), and dinner(CARB-D), each providing approximately 125 g carbohydrate in the loaded meal in a 9-MJ diet. Glucose concentrations were continuously measured with CGMS. Outcomes were assessed by postprandial peak glucose (G(max)), time spent > 12 mmol/L (T > 12), and total area under the glucose curve (AUC(20)).

RESULTS

Daily G(max) differed between treatments (P = 0.003) with CARB-L (14.2 +/- 1.0 mmol/L), CARB-E (14.5 +/- 0.9 mmol/L), and CARB-D (14.6 +/- 0.8 mmol/L) being similar but lower than CARB-B (16.5 +/- 0.8 mmol/L). Meal G(max) was weakly related to carbohydrate amount and glycemic load (r = 0.40-0.44). T > 12 differed between treatments (P = 0.014), and a treatment x fasting blood glucose (FBG) interaction (P = 0.003) was observed with CARB-L (184 +/- 74 min) < CARB-B (190 +/- 49 min) < CARB-D (234 +/- 87 min) < CARB-E (262 +/- 91 min). Total AUC(20) was not significantly different between treatments. After adjustment for FBG, treatment became significant (P = 0.006); CARB-L (10 049 +/- 718 mmol/L x 20 h) < CARB-E (10 493 +/- 706 mmol/L x 20 h) < CARB-B (10 603 +/- 642 mmol/L x 20 h) < CARB-D (10 717 +/- 638 mmol/L x 20 h).

CONCLUSION

CARB-E did not optimize blood glucose control as assessed by postprandial peaks, whereas CARB-L provided the most favorable postprandial profile.

Postprandial blood hormone and metabolite concentrations influenced by feeding frequency and feeding level in veal calves

This study hypothesized that increased feeding frequency (FF) decreases problems with glucose homeostasis seen at high feeding levels (FL) in heavy veal calves. Effects of FF and FL on hormone and metabolite concentrations were studied in 15 heavy veal calves fed once (FF1; at 12:00), twice (FF2; at 12:00 and 24:00) or four times daily (FF4; at 06:00, 12:00, 18:00 and 24:00). In period 1, all calves were fed at a low FL (FL(low); 1.5 x metabolizable energy requirements for maintenance, ME(m)). In period 2, FF2 and FF4 calves were fed at high FL (FL(high); 2.5 x ME(m)), whereas FF1 calves were still fed at FL(low). Blood was sampled every 30 min from 12:00 to 18:00 and postprandial integrated plasma hormone and metabolite concentrations (AUC(12-18 h)) were calculated. Glucose AUC(12-18 h) increased with increasing FL, but decreased with increasing FF, urea AUC(12-18 h) increased with increasing FL, whereas non-esterified fatty acid AUC(12-18 h) were unaffected by FL and FF. Insulin AUC(12-18 h) decreased with increasing FF and decreasing FL. Glucagon AUC(12-18 h) increased with increasing FL and FF. Growth hormone AUC(12-18 h) decreased, whereas insulin-like growth factor-1 and leptin AUC(12-18 h) increased with increasing FL. Mean thyroxine and 3,5,3'-triiodothyronine concentrations were modified by FF and FL. There were no FF x FL interactions, except for plasma glucose. In conclusion, postprandial hormone and metabolite responses were differentially affected by FF and (or) FL. Glucose and insulin concentrations were maximally increased at high FL and low FF. Hyperglycemia, glucosuria and excessive insulinemia were prevented by increasing FF and decreasing FL.

Effect of nibbling and gorging dietary regimens on weight and lipid profile in rat

To investigate the effects of nibbling and gorging dietary regimens on weight and lipid profiles in rat, thirty female Wistar rats, after 10 day acclimatization period, were weighed and randomly assigned into two equal groups. They were fed the same food for 60 days as eight meals at 2 h intervals starting from 6 pm (nibbling group) or as two meals at 9 pm and 6 am (gorging group). The serum lipid levels and weight of animals were determined before and after the intervention. The body weight in two groups increased significantly (p < 0.001) during the period of study but there was no significant (p > 0.05) difference between two groups before and after the intervention. Nibbling regimen caused a reduction in the serum Total Cholesterol (TC), triglyceride and LDL-C levels, whereas these parameters increased during gorging diet. However, none of these changes were significant. There was a significant decrease (p < 0.05) in TC and LDL-C levels in nibbling diet compared to gorging one. According to obtained results, nibbling regimen has better effect on lipid profile than gorging one in rat.