To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
There are high rates of obesity and low self-esteem in patients with psychosis. The occurrence of negative voice content directly about appearance is therefore plausible. Derogatory comments about appearance are likely to be distressing, increase depression and contribute to social withdrawal.
To systematically assess the occurrence of voice content regarding appearance and identify correlates.
Sixty patients experiencing verbal auditory hallucinations at least once a week in the context of non-affective psychosis completed a measure assessing positive and negative voice content about appearance. They also completed assessments about body image, self-esteem, psychiatric symptoms and well-being.
Fifty-five (91.7%) participants reported hearing voices comment on their appearance. A total of 54 (90%) patients reported negative voice content about their appearance with 30 (50%) patients experienced negative appearance comments on a daily basis. The most common negative comment was ‘the voices tell me that I am ugly’ (n = 48, 80%). There were 39 (65%) patients who reported positive voice content on appearance. The most frequent positive comment was ‘I look as nice as other people’ (n = 26, 43.3%). Negative voice content about appearance was associated with body image concerns, paranoia, voice hearing severity, depression, worry, negative self-beliefs and safety-seeking behaviours. Positive appearance voice content was associated with greater body esteem and well-being and lower levels of depression and insomnia.
Voice content about appearance is very common for patients seen in clinical services. Negative voice content may reflect – and subsequently reinforce – negative beliefs about one's appearance, low self-esteem, worry and paranoia.
Pregnant individuals who overeat are more likely to predispose their fetus to the development of metabolic disorders in adulthood. Physical training is a prevention and treatment interventional strategy that could treat these disorders, since it improves metabolism and body composition. This study assessed the protective effect of physical exercise against possible metabolic changes in generations F1 and F2, whose mothers were subjected to a high-sugar/high-fat (HS/HF) diet. Wistar rats belonging to generation F0 were distributed into four groups (n = 10): sedentary control (CSed), exercised control (CExe), sedentary HS/HF diet (DHSed) and exercised HS/HF diet (DHExe). From 21 to 120 days of age, maintained during pregnancy and lactation period, CSed/CExe animals received standard feed and DHSed/DHExe animals a HS/HF diet. Animals from the CExe/DHExe underwent physical training from 21 to 120 days of age. Male and female F1 and F2 received a normocaloric feed and did not perform any physical training, categorized into four groups (n = 10) according to the maternal group to which they belonged to. An increase in body weight, adiposity and glucose, and a change in lipid profile in F0 were observed, while exercise reduced the biochemical parameters comparing DHSed with DHExe. Maternal exercise had an effect on future generations, reducing adiposity, glucose and triglyceride concentrations, and preventing deleterious effects on glucose tolerance. Maternal overeating increased health risks both for mother and offspring, demonstrating that an HS/HF diet intake promotes metabolic alterations in the offspring. Importantly, the physical training performed by F0 proved to be protective against such effects.
Reducing food portion size could reduce energy intake. However it is unclear at what point consumers respond to reductions by increasing intake of other foods. We predicted that a change to a served portion size would only result in significant additional eating within the same meal if the resulting portion size was no longer visually perceived as ‘normal’. Participants in two crossover experiments (Study 1: N = 45; Study 2: N = 37; adults, 51% female) were served different sized lunchtime portions on three occasions that were perceived by a previous sample of participants as ‘large-normal’, ‘small-normal’, and ‘smaller than normal’ respectively. Participants were able to serve themselves additional helpings of the same food (Study 1), or dessert items (Study 2). In Study 1 there was a small but significant increase in additional intake when participants were served the ‘smaller than normal’ compared to the ‘small-normal’ portion, m difference = 39 kcal, p = .002, d = 0.35, but there was no significant difference between the ‘small-normal’ and ‘large-normal’ conditions, m difference = 20 kcal, p = .08, d = 0.24. A similar pattern was observed in Study 2: m difference = 36 kcal, p = .06, d = 0.18; m difference = 20 kcal, p = .26, d = 0.10. However, smaller portion sizes were each associated with a significant reduction in total meal intake. The findings provide preliminary evidence that reductions that result in portions appearing ‘normal’ in size may limit additional eating, but confirmatory research is needed. (250/250 words)
Salusins have emerged as a new biomarker that reflects an increased inflammatory state, which is associated with cardiovascular risk. We investigated the predictive value and usefulness of salusins as an inflammatory biomarker in obese children. This prospective cohort study included 75 obese children and 101 healthy children (as a control group). Salusin-α, Salusin-β, and various cardiovascular parameters were assessed in both groups. Correlation analyses of Salusin-α and Salusin-β with body mass index standard deviation scores and inflammatory and cardiovascular markers were performed. The mean patient age was 11.9±2.4 years for the obese group and 12.5±2.1 years for the control group. The obese children had a significantly higher heart rate, systolic blood pressure, diastolic blood pressure, epicardial adipose tissue thickness, and left ventricular mass than did the children in the control group. There was no significant correlation between Salusin-α and Salusin-β and body mass index; however, there was a negative correlation between Salusin- α and diastolic blood pressure (r = 0.277, p = 0.004). Overall, there was no significant difference in the Salusin-α and Salusin-β levels between obese and healthy children. However, a negative correlation was found between Salusin-α and diastolic blood pressure. Although this result suggests that Salusin-α might be an early marker of cardiovascular involvement in obese children, further studies are needed to demonstrate the predictive value of salusins.
Evidence suggests that low birth weight and fetal exposure to extreme maternal undernutrition is associated with cardiovascular disease in adulthood. Hyperemesis gravidarum, a clinical entity characterized by severe nausea and excess vomiting leading to a suboptimal maternal nutritional status during early pregnancy, is associated with an increased risk of adverse pregnancy outcomes. Several studies also showed that different measures related to hyperemesis gravidarum, such as maternal daily vomiting or severe weight loss, are associated with increased risks of adverse fetal pregnancy outcomes. Not much is known about long-term offspring consequences of maternal hyperemesis gravidarum and related measures during pregnancy. We examined the associations of maternal daily vomiting during early pregnancy, as a measure related to hyperemesis gravidarum, with childhood cardiovascular risk factors.
In a population-based prospective cohort study from early pregnancy onwards among 4,769 mothers and their children in Rotterdam, the Netherlands, we measured childhood body mass index, total fat mass percentage, android/gynoid fat mass ratio, preperitoneal fat mass area, blood pressure, lipids, and insulin levels. We used multiple regression analyses to assess the associations of maternal vomiting during early pregnancy with childhood cardiovascular outcomes.
Compared with the children of mothers without daily vomiting during early pregnancy, the children of mothers with daily vomiting during early pregnancy had a higher childhood total body fat mass (difference 0.12 standard deviation score [SDS]; 95% confidence interval [CI] 0.03–0.20), android/gynoid fat mass ratio (difference 0.13 SDS; 95% CI 0.04–0.23), and preperitoneal fat mass area (difference 0.10 SDS; 95% CI 0–0.20). These associations were not explained by birth characteristics but partly explained by higher infant growth. Maternal daily vomiting during early pregnancy was not associated with childhood blood pressure, lipids, and insulin levels.
Maternal daily vomiting during early pregnancy is associated with higher childhood total body fat mass and abdominal fat mass levels, but not with other cardiovascular risk factors. Further studies are needed to replicate these findings, to explore the underlying mechanisms and to assess the long-term consequences.
Obesity represents a tremendous global health problem. Studies over the past decade have suggested that food addiction (FA), i.e., physical cravings for certain foods —high in fat/sugar - and addiction-like overeating of these types of food, is a likely contributor to the obesity epidemic. While FA has been studied extensively, there are some significant gaps in the literature that need to be addressed:
I) Most estimates of the prevalence of FA are based on nonprobability sampling, which significantly limits the representativeness of the prevalence estimates.
II) Although addiction disorders are prevalent among individuals with mental disorders, large studies of FA among patients with clinically diagnosed mental disorders are lacking.
III) Most addiction disorders are heritable, but the familial transmission of FA remains virtually unknown.
IV) Due to a relative lack of longitudinal studies, little is known about the risk factors for and outcomes of FA. To close these gaps in the literature, we designed the Food Addiction Denmark (FADK) project.
The FADK study is a nationwide survey with retrospective and prospective register-based elements. Four randomly sampled cohorts were invited to participate in the survey: 5000 adults and 3750 adolescents from the general population and 5000 adults and 3529 adolescents with a mental disorder. The FADK questionnaire includes the Yale Food Addiction Scale 2.0 and rating scales measuring psychopathology. Data from Danish health and socioeconomic registers will be linked to all invitees.
We expect that the FADK project will contribute significantly to our understanding of FA.
The ongoing demographic, nutritional and epidemiological transitions in sub-Saharan Africa highlight the importance of monitoring overweight and obesity. We aimed to assess the prevalence of overweight and obesity in Mozambique in 2014/2015 and compare the estimates with those obtained in 2005.
Cross-sectional study conducted in 2014/2015, following the WHO Stepwise Approach to Chronic Disease Risk Factor Surveillance (STEPS). Prevalence estimates with 95 % CI were computed for different categories of BMI and abdominal obesity, along with age-, education- and income-adjusted OR. The age-standardized prevalence in the age group 25–64 years was compared with results from a STEPS survey conducted in 2005.
Representative sample of the population aged 18–64 years (n 2595).
Between 2005 and 2014/2015, the prevalence of overweight and obesity increased from 18·3 to 30·5 % (P < 0·001) in women and from 11·7 to 18·2 % (P < 0·001) in men. Abdominal obesity increased among women (from 9·4 to 20·4 %, P < 0·001), but there was no significant difference among men (1·5 v. 2·1 %, P = 0·395). In 2014/2015, the prevalence of overweight and obesity was more than twofold higher in urban areas and in women; in the age group 18–24 years, it was highest in urban women and lowest in rural men.
In Mozambique, there was a steep increase in the prevalence of overweight and obesity among adults between 2005 and 2014/2015. Overweight and obesity are more prevalent in urban areas and among women, already affecting one in five urban women aged 18–24 years.
Body mass index z-score (BMIz) based on the CDC growth charts is widely used, but it is inaccurate above the 97th percentile. We explored the performance of alternative metrics based on the absolute distance or % distance of a child’s BMI from the median BMI for sex and age.
We used longitudinal data from 5628 children who were first examined < 12 y to compare the tracking of three BMI metrics: distance from median, % distance from median, and % distance from median on a log scale. We also explored the effects of adjusting these metrics for age differences in the distribution of BMI. The intra-class correlation coefficient (ICC) was used to compare tracking of the metrics.
The aim of the study is to determine differences in dietary parameters (energy and nutrient intake, adherence to the Mediterranean diet and food groups consumption) in metabolically healthy overweight-obese (MHOO) vs. metabolically unhealthy overweight-obese (MUOO) middle-aged adults. 51 middle-aged adults were classified as MHOO or MUOO. We evaluate body mass index and blood pressure were evaluated following the recommendations. HDL, triglycerides and blood glycaemia were measured in blood samples. Blood pressure was also assessed. Dietary factors were assessed through three 24-hours recalls, a validated food frequency questionnaire and the PREDIMED questionnaire. All variables were evaluated between September and October 2016 and 2017. Our results showed that MHOO individuals registered a higher fish consumption (P=0.035), higher compliance (lower consumption) in the Commercial sweets and confectionery item of the PREDIMED questionnaire (P=0.036). No differences were noted in other dietary factors including energy and nutrient intake, other food groups consumption, and in the PREDIMED total score. Although, a near-significant trend toward significance was observed in nuts consumption, wine and fish items of the PREDIMED questionnaire. In conclusion, higher fish consumption and a higher compliance in the Commercial sweets and confectionery item of the PREDIMED questionnaire were observed in MHOO middle-aged adults.
We cross-sectionally investigated irregular breakfast consumption and food timing patterns in relation to weight status and inflammation among 644 participants in the Cancer Prevention Study-3 Diet Assessment Sub-study. Breakfast consumption, and the individual means and the intra-individual standard deviation (iSD) of time at first intake of the day, duration of daily intake window, and midpoint of daily intake window were collected via six 24-hour recalls and examined in relation to body mass index (BMI), waist circumference (WC), and inflammation (GlycA). Compared to consuming breakfast on all six recalls, linear regression models showed those who consumed breakfast on 5 or 4 of the days had a 1.29 (95% CI: 0.19, 2.38) and 1.64 kg/m2 (95% CI: 0.12, 3.16) higher BMI; no association for consuming breakfast ≤3 days. 1-hour later in the average time of first intake was associated with a 0.44 kg/m2 higher BMI (95% CI: 0.04, 0.84). A 1-hour increase in the iSD of first intake, was associated with a 1.12 (95% CI: 0.49, 1.75) higher BMI; iSD in duration and midpoint of intake window were significant prior to additional adjustment for iSD in first intake. 1-hour increases in iSD for first intake time (β: 0.15; 95% CI: 0.04, 0.26) and midpoint of intake window (β: 0.16; 95% CI: 0.02, 0.31) were associated with higher GlycA. No associations were observed for WC independent of BMI. The results provide evidence that irregularity in breakfast consumption and daily intake timing patterns, particularly early in the day, may be related to weight status and inflammation.
Although bariatric surgery is approved for a woman of child-bearing age with an interest in subsequent pregnancy, reports of in utero growth issues during pregnancy have garnered a closer look at the impact of maternal surgical weight loss on the pre- and postpartum periods. Offspring of dams having received vertical sleeve gastrectomy (VSG) are born small-for-gestational age and have increased risk for metabolic syndrome later in life. Here, we aimed to determine whether the postnatal catch-up growth trajectory of bariatric offspring may be affected by milk composition. Milk samples were collected at postnatal day 15/16 from dams having received VSG surgery and fed a high-fat diet (HFD) (H-VSG), Sham surgery and fed chow (C-Sham), or Sham surgery and fed HFD (H-Sham). Milk obtained from H-VSG dams had elevated glucose (P < 0.05) and significantly reduced triglyceride content (P < 0.01). Milk from H-Sham dams had the lowest amount of milk protein (P < 0.05). Fatty acid composition measured by fractionation was largely not affected by surgery but rather maternal diet. No difference was observed in milk leptin levels; however, insulin, adiponectin, and growth hormone levels were significantly increased in milk from H-VSG animals. H-Sham had the lowest level of immunoglobulin (Ig)A, whereas IgG was significantly reduced in H-VSG. Taken together, the quality of milk from H-VSG dams suggests that milk composition could be a factor in reducing the rate of growth during the lactation period.
Altered gut microbial ecology contributes to the development of metabolic diseases including obesity. However, studies based on different populations have generated conflicting results due to diet, environment, methodologies, etc. The aim of our study was to explore the association between gut microbiota and Body Mass Index (BMI) in Chinese college students. 16S next-generation sequencing (NGS) was used to test the gut microbiota of 9 lean, 9 overweight/obesity, and 10 normal-weight male college students. The differences of gut microbiota distribution among three groups were compared, and the relationship between the richness, diversity, composition of gut microbiota and BMI were analyzed. The predominant phyla Bacteroidetes and Firmicutes were further confirmed by real-time PCR. Metagenomic biomarker discovery was conducted by Linear discriminant analysis (LDA) Effect Size (LEfSe). NGS revealed that gut microbiota composition was different among three groups, but there was no difference in the abundance ratio of Firmicutes/ Bacteroidetes. Several bacterial taxa were in linear relationship with BMI (positive relationship: uncultured bacterium (Bacteroides genus); negative relationship: Porphyromonadaceae, Acidaminococcaceae, Rikenellaceae, Desulfovibrionaceae, Blautia, Anaerotruncus, Parabacteroides, Alistipes). Moreover, gut microbiota diversity decreased with the increase of BMI. And LEfSe analyze indicated that Blautia, Anaerotruncus and its uncultured species were significantly enriched in the lean group (LDA score≥3), Parasuterella and its uncultured species were significantly enriched in the overweight/obese groups(LDA score≥3). In general, gut microbiota composition and microbial diversity were associated with BMI in Chinese male college students. Our results might enrich the understanding between gut microbiota and obesity.
To analyse the evolution of the soft drink industry’s use of self-regulation as a response to obesity and examine the motivations driving its development and the strategies used to promote it to policy makers.
We used a data set of industry documents published by the Australian Beverages Council (ABC) between 1998 and 2016. We analysed how the ABC voiced its political motivations about self-regulation and what internal nutrition policies it developed prior to its public launch of self-regulation. We also analysed two promotional strategies: funding research and writing policy submissions.
Between 1998 and 2006, the ABC shifted from a defensive strategy that denied the role of its products in obesity to more conciliatory strategy that emphasised the role of the soft drink industry in solutions to obesity. The ABC deliberately timed the launch of its self-regulation to coincide with an international public health congress. Following its launch, the ABC funded research demonstrating the efficacy of self-regulation and wrote submissions to government nutrition policies arguing that further regulation was unnecessary.
The soft drink industry uses self-regulation to bolster its reputation and influence nutrition policy. Strategic timing plays a key role in the political influence of self-regulation.
To investigate the association between dietary patterns (DP) and overweight risk in the Malaysian Adult Nutrition Surveys (MANS) of 2003 and 2014.
DP were derived from the MANS FFQ using principal component analysis. The cross-sectional association of the derived DP with prevalence of overweight was analysed.
Nationally representative sample of Malaysian adults from MANS (2003, n 6928; 2014, n 3000).
Three major DP were identified for both years. These were ‘Traditional’ (fish, eggs, local cakes), ‘Western’ (fast foods, meat, carbonated beverages) and ‘Mixed’ (ready-to-eat cereals, bread, vegetables). A fourth DP was generated in 2003, ‘Flatbread & Beverages’ (flatbread, creamer, malted beverages), and 2014, ‘Noodles & Meat’ (noodles, meat, eggs). These DP accounted for 25·6 and 26·6 % of DP variations in 2003 and 2014, respectively. For both years, Traditional DP was significantly associated with rural households, lower income, men and Malay ethnicity, while Western DP was associated with younger age and higher income. Mixed DP was positively associated with women and higher income. None of the DP showed positive association with overweight risk, except for reduced adjusted odds of overweight with adherence to Traditional DP in 2003.
Overweight could not be attributed to adherence to a single dietary pattern among Malaysian adults. This may be due to the constantly morphing dietary landscape in Malaysia, especially in urban areas, given the ease of availability and relative affordability of multi-ethnic and international foods. Timely surveys are recommended to monitor implications of these changes.
Currently the world is facing an incredibly costly epidemic of obesity. Almost two-thirds of UK adults are either overweight or obese with estimated financial costs to the UK economy alone of £27 billion per year. While fundamentally obesity is a disorder of energy balance, several decades of research has demonstrated that maintaining energy balance is much more complex than the ‘energy in equals energy out’ equation that was once touted. The purpose of the 2018 Nutrition Society Summer Conference, ‘Getting energy balance right’ was to provide insight into the numerous factors influencing energy balance, considering varying needs across the lifespan, while highlighting advances and gaps in knowledge. Papers presented in this issue illustrate the wide range of factors involved in maintaining energy balance, including: epigenetics, the gut microbiome, physical activity and dietary factors including sugar. Given the complexity of energy balance, systems approaches were highlighted as useful for both understanding metabolism and pathophysiology, and for understanding how public health interventions to treat and prevent obesity should be implemented. The meeting concluded that numerous stakeholders, from individuals, to schools, industry and government, have roles to play in fostering a positive food environment that facilitates the maintenance of energy balance throughout the lifespan.
The global ageing population and the long prodromal period for the development of cognitive decline and dementia brings a need to understand the antecedents of both successful and impaired cognitive ageing. It is increasingly apparent that the trajectory of risk-factor change, as well as the level of the risk factor, may be associated with an increased or decreased risk of cognitive decline or dementia.
Our aim was to summarise the published evidence and to generate hypotheses related to risk-factor trajectories and risk of incident cognitive decline or dementia.
We collated data from longitudinal observational studies relating to trajectory of blood pressure, obesity and cholesterol and later cognitive decline or dementia using standard systematic review methodology. The databases MEDLINE, Embase and PsycINFO were searched from inception to 26 April 2018.
Thirteen articles were retained for inclusion. Analytical methods varied. Our summary of the current evidence base suggests that first body mass index and then blood pressure rises and then falls more steeply in those who go on to develop dementia. The evidence for cholesterol was less consistent.
Based on our review we present the hypothesis that weight falls around 10 years and blood pressure around 5 years before diagnosis. Confirmatory work is required. However, characterisation of risk according to combinations and patterns of risk factors may ultimately be integrated into the assessments used to identify those at risk of receiving a diagnosis of cognitive decline or dementia in late life.
We evaluated the effects of high-Ca fat-free milk v. low-Ca control diet on adiposity and on glycaemic control. Fourteen subjects with type 2 diabetes (aged 49·5 (sd 8·6) years, BMI 29·4 (sd 4·5) kg/m2, low habitual Ca consumption (<600 mg/d)) were included in this randomised, crossover clinical trial. Subjects participated in two 12-week experimental sessions (high-Ca fat-free milk (HC) or low-Ca control (LC)) separated by 8-week washout. Subjects daily consumed in the laboratory a breakfast shake containing 700 mg (HC) or 6·4 mg (LC) of Ca. Energy-restricted diets containing 800 mg of dietary Ca/d were prescribed. Dietary records data indicated the consumption of 1200 mg of Ca/d during HC and of 525 mg of Ca/d during LC. There was a greater reduction in body weight, body fat mass, waist circumference and waist:hip ratio after HC. Serum 25-hydoxyvitamin D and homeostatic model assessment-2 β-cell function (HOMA2-%B) increased, and serum uric acid, parathormone (PTH) and glycated Hb (HbA1c) concentrations reduced after HC. In addition, changes from baseline in terms of serum uric acid, glucose, HbA1c and PTH concentrations were lower, and those of HOMA2-%B, serum Ca and 25-hydoxyvitamin D were higher after the HC than after LC. The consumption of approximately three servings of fat-free milk and 1200 mg of dietary Ca/d enhanced weight loss, improved body composition and promoted glycaemic control in subjects with type 2 diabetes and low habitual Ca consumption (<600 mg/d).
We aimed to study the eating behavioral traits that associate with body mass index (BMI) among BMI-discordant twin pairs. This cross-sectional study examined self-reported eating behaviors in 134 healthy young adult twin pairs (57 monozygotic [MZ] and 77 same-sex dizygotic [DZ]), of whom 29 MZ and 46 DZ pairs were BMI discordant (BMI difference ≥ 3 kg/m2). In both MZ and DZ BMI-discordant pairs, the heavier co-twins reported being less capable of regulating their food intake optimally than their leaner co-twins, mainly due to ‘frequent overeating’. Furthermore, the heavier co-twins reported augmented ‘disinhibited eating’, ‘binge-eating scores’ and ‘body dissatisfaction’. The twins agreed more frequently that the heavier co-twins (rather than the leaner co-twins) ate more food in general, and more fatty food, in particular. No significant behavioral differences emerged in BMI-concordant twin pairs. Overeating — measured by ‘frequent overeating’, ‘disinhibited eating’ and ‘binge-eating score’ — was the main behavioral trait associated with higher BMI, independent of genotype and shared environment.
The metabolic syndrome is a cluster of disorders dominated by abdominal obesity, hypertriacylglycerolaemia, low HDL-cholesterol, high blood pressure and high fasting glucose. Diet modification is a safe and effective way to treat the metabolic syndrome. Dietary Approaches to Stop Hypertension (DASH) is a dietary pattern rich in fruits, vegetables and low-fat dairy products, and low in meats and sweets. DASH provides good amounts of fibre, K, Ca and Mg, and limited quantities of total fat, saturated fat, cholesterol and Na. Although DASH was initially designed for the prevention or control of hypertension, using a DASH diet has other metabolic benefits. In the present review, the effect of each dietary component of DASH on the risk factors of the metabolic syndrome is discussed. Due to limited fat and high fibre and Ca content, individuals on the DASH diet are less prone to overweight and obesity and possess lower concentrations of total and LDL-cholesterol although changes in TAG and HDL-cholesterol have been less significant and available evidence in this regard is still inconclusive. Moreover, high amounts of fruit and vegetables in DASH provide great quantities of K, Mg and fibre, all of which have been shown to reduce blood pressure. K, Mg, fibre and antioxidants have also been effective in correcting glucose and insulin abnormalities. Evidence is provided from cross-sectional investigations, cohort studies and randomised controlled trials, and, where available, from published meta-analyses. Mechanisms are described according to human studies and, in the case of a lack of evidence, from animal and cell culture investigations.
Glucagon-like peptide-1 (GLP-1) is an incretin hormone that regulates postprandial glycaemic response by enhancing insulin secretion. We previously demonstrated that the postprandial GLP-1 response was enhanced during the development of diet-induced obesity in rats. However, the physiological relevance of the enhanced GLP-1 response remained unclear. We aimed to determine the role of endogenous GLP-1 during obesity development. Male Sprague–Dawley rats were given either a control diet or a high-fat/high-sucrose (HFS, 30 % fat and 40 % sucrose, weight basis) diet with or without continuous administration of the GLP-1 receptor antagonist, exendin (9–39) (Ex9, 100 µg/d), for 5 weeks. Meal tolerance tests (MTT) were performed to assess postprandial glucose, insulin and GLP-1 responses to a liquid diet administration (15 kcal (63 kJ)/10 ml per kg body weight) every 2 weeks. The AUC of postprandial glucose in the HFS group was similar to the control group in both MTT (P = 0·9665 and P = 0·3475, respectively), whereas AUC of postprandial GLP-1 (after 4 weeks,P = 0·0457) and of insulin (after 2 and 4 weeks, P = 0·0486 and P = 0·0110) was higher in the HFS group compared with the control group. In the Ex9 group, AUC of postprandial glucose (P = 0·0297 and P = 0·0486) was higher along with a lower insulin response compared with the HFS group (P = 0·0564 and P = 0·0281). These results suggest that enhancement of the postprandial GLP-1 response during obesity development has a role in maintaining a normal postprandial glycaemic response. Hence, enhancing endogenous GLP-1 secretion by certain materials could be a potential target for prevention of glucose intolerance.