Trends and dietary determinants of overweight and obesity in a multiethnic population

Associations between dietary intake, physical activity, and obesity among public school teachers in Jeddah, Saudi Arabia

Objective

We aimed to assess the dietary intake of certain food groups in a representative sample of public-school teachers living in Jeddah city. We also, examined the association of dietary intake with physical activity and obesity among schoolteachers.

Methods

The study was a cross-sectional online survey, conducted among 640 (177 male, 463 female) schoolteachers aged between 20 and 62 years old and working in public primary, intermediate, and high schools in Jeddah. Measurements included gender, weight, height, body mass index (BMI), health problems, and lifestyle behaviours, including physical activity levels, smoking status, and dietary intake.

Results

Based on gender, number of non-smoking women (94%) was higher than number of non-smoking men (57.1%) (P < 0.001). However, men were more active than women (P = 0.03). Regarding BMI, there were more overweight men than women, while obese women numbered more than men (P = 0.003). There was no significant difference in dietary intake between men and women except that men consumed more soft drinks than women (P = 0.002). Lower physically active schoolteachers were less likely to consume salad (OR = 0.6, 95% CI 0.4-0.9; P = 0.02), vegetables (OR = 0.6, 95% CI 0.3-0.9; P = 0.01), beans and legumes (OR = 0.4, 95% CI 0.2-0.7; P = 0.005), wholegrain bread (OR = 0.6, 95% CI 0.4-0.9; P = 0.03), dairy products (OR = 0.6, 95% CI 0.4-0.9; P = 0.01), snacks (OR = 0.5, 95% CI 0.2-0.8; P = 0.01), and fish (OR = 0.4, 95% CI 0.2-0.9; P = 0.04) compared to those with high levels of physical activity. Only fruit intake was considered statistically significant (OR = 0.4, 95% CI 0.3-0.7; P = 0.003). The study found a relationship between the BMI of schoolteachers and food intake. Obese schoolteachers had lower consumption of fruits (OR = 0.3, 95% CI 0.2-0.7; P = 0.007) and white meat (OR = 0.5, 95%CI 0.3-0.9; P = 0.03) than schoolteachers in the normal weight group.

Conclusion

The high prevalence of physical activity, dietary intake and body weight among Saudi teachers is a major public health concern. The present study identified several lifestyle factors associated with body weight that may represent valid targets for the prevention and management of obesity among Saudi school teachers. Promoting active lifestyles and healthy diets would be primary targets for obesity prevention.

Meat consumption and the risk of general and central obesity: the Shahedieh study

Objective

This study aimed to investigate the relations of total meat intake and its subtypes, including red and processed meat, white meat, poultry, fish, and organ meat to the risk of general/central obesity.

Methods

This cross-sectional study included a total of 7312 Iranian adults with the age range of 35–70 years from the Shahedieh cohort study, Yazd, Iran. Dietary intake of subjects was evaluated using a validated 120-item Food Frequency Questionnaire. General obesity was defined as body mass index ≥ 30 kg/m2 and central obesity as waist circumference ≥ 102 cm in men and ≥ 88 cm in women.

Results

After controlling for potential covariates including energy intake, age, marital status, gender, physical activity, supplement use, house possession, education, family size, current smoking, night shift working, history of thyroid disease and depression, and intakes of vegetables, legumes, nuts, fruits, whole grains, and dairy, a significant direct association was found between the higher consumption of white meat (OR = 1.31; 95% CI: 1.06–1.61) and poultry (OR = 1.23; 95% CI: 1.04–1.45) with odds of general obesity. Processed meat was a significant predictor for central obesity in the fully adjusted model, so that individuals in the fourth quartile of processed meat intake, compared with those in the first quartile, had a 22% (OR = 1.22; 95% CI: 1.04–1.43) increased risk to be centrally obese.

Conclusion

This study reveals that higher intakes of white meat and poultry are associated with increased risk of general obesity, while, processed meat consumption was associated with central obesity.

Alkylresorcinol, a biomarker for whole grain intake, and its association with osteoarthritis: the MOST study

INTRODUCTION

Higher intake of fiber has been associated with lower risk of incident symptomatic osteoarthritis (OA). We examined whether levels of alkylresorcinol (AR), a marker of whole grain intake, were associated with OA in subjects in The Multicenter Osteoarthritis (MOST) Study.

METHOD

Knee x-rays and knee pain were assessed at baseline and through 60-months. Stored baseline fasting plasma samples were analyzed for AR homologues (C17:0, C19:0, C21:0, C23:0, C25:0) and total AR levels (AR sum). Two nested case-control studies, one for incident radiographic OA and one for incident symptomatic OA were performed with participants re-assessed at 15, 30 and 60 months. Multivariable conditional logistic regression with baseline covariates including age, sex, BMI, physical activity, quadriceps strength, race, smoking, depressive symptoms, diabetes and knee injury tested the association of log transformed AR levels with OA outcomes.

RESULTS

Seven hundred seventy-seven subjects were, on average, in their 60's, and most were women. For 60-month cumulative incidence, there was no significant association between quartiles of AR concentration and incident radiographic (e.g., for incident radiographic OA, highest vs lowest quartile of AR sum showed RR = 0.93 (95% CI 0.59, 1.47), and for symptomatic OA RR was 1.22 (95% CI 0.76, 1.94). In secondary analyses examining 30-month incidence, high AR levels were associated with a reduced risk of X-ray OA (RR = 0.31 (95% CI 0.15, 0.64).

CONCLUSION

In primary analyses, AR levels were not associated with risk of OA, but secondary analyses left open the possibility that high AR levels may protect against OA.

Gut Hormones in Health and Obesity: The Upcoming Role of Short Chain Fatty Acids

We are currently facing an obesity pandemic, with worldwide obesity rates having tripled since 1975. Obesity is one of the main risk factors for the development of non-communicable diseases, which are now the leading cause of death worldwide. This calls for urgent action towards understanding the underlying mechanisms behind the development of obesity as well as developing more effective treatments and interventions. Appetite is carefully regulated in humans via the interaction between the central nervous system and peripheral hormones. This involves a delicate balance in external stimuli, circulating satiating and appetite stimulating hormones, and correct functioning of neuronal signals. Any changes in this equilibrium can lead to an imbalance in energy intake versus expenditure, which often leads to overeating, and potentially weight gain resulting in overweight or obesity. Several lines of research have shown imbalances in gut hormones are found in those who are overweight or obese, which may be contributing to their condition. Therefore, this review examines the evidence for targeting gut hormones in the treatment of obesity by discussing how their dysregulation influences food intake, the potential possibility of altering the circulating levels of these hormones for treating obesity, as well as the role of short chain fatty acids and protein as novel treatments.

Macronutrient composition of the diet and long-term changes in weight and waist circumference in the EPIC-Italy cohort

BACKGROUND AND AIMS

The overall macronutrient composition of diet, rather than just calorie intake, may influence long-term changes of anthropometry. We investigated relationships between dietary macronutrient composition and long-term changes in weight and waist circumference in participants of the EPIC-Italy - the Italian section of the European Prospective Investigation into Cancer and Nutrition - study.

METHODS AND RESULTS

A total of 32,119 participants provided anthropometric measures at recruitment and 12 years later (mean). Diet at recruitment was assessed using validated semi-quantitative food frequency questionnaires. Weight and waist changes associated with replacing 10% of energy from one macronutrient with 10% of energy from another macronutrient were assessed by multivariable linear regression. Increased energy from total protein at the expense of any other macronutrient was significantly associated with increased weight and waist circumference. Increased starch at the expense of sugar and total protein was associated with significantly decreased weight and waist circumference; when starch replaced total fat, weight significantly decreased. Increased sugar at the expense of starch and total fat was significantly associated with increased weight and waist circumference; but increase at the expense of total protein was significantly associated with decreased weight and waist circumference.

CONCLUSION

Our results suggest that increasing protein at the expense of fat or carbohydrates, and reducing starch by increasing other macronutrients, might be associated with increased weight and waist gain.

Sociodemographic factors influencing island foods consumption in the Pacific Islander Health Study

Objectives: Pacific Islander Americans are a small, but quickly growing population that experiences alarming disparities in obesity and obesity-related chronic illnesses influenced by dietary patterns. This population also has a unique culinary heritage including traditional foods and more contemporary imports such as tinned meats and refined carbohydrates. This analysis is a novel attempt to understand the sociodemographic factors influencing island foods consumption.Design: A sample of 240 Samoan and Tongan adults in California from the Pacific Islander Health Study was used. Following univariate and bivariate analyses, a series of four multivariable regression models were created to predict past week frequency of island foods consumption after sequential adjustment for demographic, socioeconomic, and cultural covariates.Results: Participants reported consuming island foods an average of 2.93 times in the previous week, with the largest proportion of participants (20.42%) reporting eating island foods 6 or more times. Age and Samoan ethnicity were initially significant, positive predictors of island foods consumption, but their effect was attenuated after addition of cultural covariates. With the third model that adjusted for birthplace, financial insecurity and Tongan birthplace were positive predictors. Both lost significance in the fourth and final model upon addition of cultural affinity, which was positively associated with island foods.Conclusion: Understanding how sociodemographic factors are associated with island foods consumption is a first step in understanding the broad way in which an ethnically specific dietary pattern may be associated with obesity-related chronic illness risk among Pacific Islander Americans.

Preferences for Sweet and Fatty Taste in Children and Their Mothers in Association with Weight Status

Strong preferences for sweet and fat tastes (characters) are associated with the consumption of foods high in calories. The taste preferences, especially the sweet and fat tastes (characters), might be one of the factors predisposing children to become overweight and/or develop obesity. The aim of the study is to assess taste preferences in children and their mothers in association with their weight status. In the study, 150 children aged 8–15 were included; among them, 75 had overweight and/or obesity, and 150 mothers of whom 69 were overweight and/or obese. Body composition estimates were obtained using a bioelectrical impedance analysis-body height was measured using a stadiometerSeca 213. Sensory tests were carried out using apple juice of various sugar content and crackers of various fat content. Results show that children prefer a sweet taste more often than their mothers (50.0% vs. 35.3%, p = 0.009). In the group of children who preferred the high-sweet taste, there were twice as many obese children when compared to the group who preferred the low-sweet taste. Similar relationships applied to mothers. Preferences for fat taste (character) among mothers increased the risk of obesity among their children (39% vs. 20%; p = 0.039). Taste preferences, especially a sweet taste preference, seem to be one of the important factors determining overweight and obesity in children and adults. The fat taste(character) preferences in mothers correlate with the overweight and/or obesity of their children, while such preferences among children were not significantly different irrespective of body weight status.

Dietary fibers inhibit obesity in mice, but host responses in the cecum and liver appear unrelated to fiber-specific changes in cecal bacterial taxonomic composition

Dietary fibers (DF) can prevent obesity in rodents fed a high-fat diet (HFD). Their mode of action is not fully elucidated, but the gut microbiota have been implicated. This study aimed to identify the effects of seven dietary fibers (barley beta-glucan, apple pectin, inulin, inulin acetate ester, inulin propionate ester, inulin butyrate ester or a combination of inulin propionate ester and inulin butyrate ester) effective in preventing diet-induced obesity and links to differences in cecal bacteria and host gene expression. Mice (n = 12) were fed either a low-fat diet (LFD), HFD or a HFD supplemented with the DFs, barley beta-glucan, apple pectin, inulin, inulin acetate ester, inulin propionate ester, inulin butyrate ester or a combination of inulin propionate ester and inulin butyrate ester for 8 weeks. Cecal bacteria were determined by Illumina MiSeq sequencing of 16S rRNA gene amplicons. Host responses, body composition, metabolic markers and gene transcription (cecum and liver) were assessed post intervention. HFD mice showed increased adiposity, while all of the DFs prevented weight gain. DF specific differences in cecal bacteria were observed. Results indicate that diverse DFs prevent weight gain on a HFD, despite giving rise to different cecal bacteria profiles. Conversely, common host responses to dietary fiber observed are predicted to be important in improving barrier function and genome stability in the gut, maintaining energy homeostasis and reducing HFD induced inflammatory responses in the liver.

Does high-carbohydrate intake lead to increased risk of obesity? A systematic review and meta-analysis

OBJECTIVES

The present study aimed to test the association between high and low carbohydrate diets and obesity, and second, to test the link between total carbohydrate intake (as a percentage of total energy intake) and obesity.

SETTING, PARTICIPANTS AND OUTCOME MEASURES

We sought MEDLINE, PubMed and Google Scholar for observation studies published between January 1990 and December 2016 assessing an association between obesity and high-carbohydrate intake. Two independent reviewers selected candidate studies, extracted data and assessed study quality.

RESULTS

The study identified 22 articles that fulfilled the inclusion and exclusion criteria and quantified an association between carbohydrate intake and obesity. The first pooled strata (high-carbohydrate versus low-carbohydrate intake) suggested a weak increased risk of obesity. The second pooled strata (increasing percentage of total carbohydrate intake in daily diet) showed a weak decreased risk of obesity. Both these pooled strata estimates were, however, not statistically significant.

CONCLUSIONS

On the basis of the current study, it cannot be concluded that a high-carbohydrate diet or increased percentage of total energy intake in the form of carbohydrates increases the odds of obesity. A central limitation of the study was the non-standard classification of dietary intake across the studies, as well as confounders like total energy intake, activity levels, age and gender. Further studies are needed that specifically classify refined versus unrefined carbohydrate intake, as well as studies that investigate the relationship between high fat, high unrefined carbohydrate-sugar diets.

PROSPERO REGISTRATION NUMBER

CRD42015023257.

Association of white and red meat consumption with general and abdominal obesity: a cross-sectional study among a population of Iranian military families in 2016

PURPOSE

To assess the association of red and white meat consumption with general and abdominal obesity among Iranian military families.

METHODS

In this cross-sectional study, 525 subjects with age range of 19-55 years belong to military families of Army of Islamic Republic of Iran were recruited during 2016. Dietary data were collected using semi-quantitative food-frequency questionnaire. A self-reported questionnaire was used to collect data on demographic characteristics and anthropometric measurements. General obesity was defined as body mass index ≥25 kg/m² and abdominal obesity as waist circumference ≥80 cm for women and ≥ 94 cm for men. Finally, we had complete data on 170 subjects for analysis.

RESULTS

Mean age of subjects was 33.78 ± 6.48. We found a significant positive association between red meat consumption and abdominal obesity in fully adjusted model, so that subjects in the fourth quartile had 4.51 more odds to be abdominally obese compared with those in the first quartile of red meat consumption (OR 4.51, 95% CI 1.32-15.40). Such relationship was not seen for general obesity. In addition, white meat consumption was not associated with general and abdominal obesity either before or after adjustment for covariates.

CONCLUSIONS

Red meat consumption was positively associated with abdominal obesity. No significant relationship was found between white meat consumption, and general and abdominal obesity. Therefore, further studies are needed to shed light our findings.

Relative Influence of Socioeconomic, Psychological and Sensory Characteristics, Physical Activity and Diet on 5-Year Weight Gain in French Adults

Individual characteristics, dietary intake and physical activity influence weight status; however, the contribution of each factor to weight change has not been studied. The objective was to confirm a conceptual framework by simultaneously assessing the relative influence of socioeconomic, psychological and sensory characteristics, physical activity, and dietary intake on five-year weight gain in French adults. Individual characteristics, physical activity, and dietary data were assessed at baseline in 8014 participants in the NutriNet-Santé cohort. Self-reported anthropometric data were collected at baseline and five years later. Structural equation models, stratified by baseline body mass index (BMI), were used to perform analyses. Dietary restraint was a direct predictor of weight gain, with a stronger effect than age or intake of energy-dense foods, both in non-overweight and overweight participants. In non-overweight individuals only, intake of nutrient-dense foods and physical activity were inversely associated with weight gain. Regarding dietary intake, fat liking was the most important predictor of nutrient-dense food intake and was also related to energy-dense food intake. In these models, dietary restraint appears to be a direct predictor of weight gain and fat liking is a strong determinant of dietary intake. The influence of dietary restraint on weight gain, not explained by diet, warrants further investigation.

Prevalence of obesity and affecting factors in physically disabled adults living in the city centre of Malatya

OBJECTIVE

The purpose of this study was to investigate the prevalence of obesity, and the risk factors associated with it, in physically disabled adults living in the city centre of Malatya, Turkey.

METHOD

This research was designed as a cross-sectional study conducted on physically disabled people aged 20-65 years living in the city centre of Malatya. The prevalence of obesity in disabled people was within 95% CIs, the power was calculated as 80%, and the sample size of our population was calculated as 258 individuals.

RESULTS

The prevalence of obesity was found to be 13.2%. The relationship between disability type and obesity status was found to be significant. The prevalence of obesity was 21.3% in visually impaired people, 17.9% in speech-impaired people, 17.8% in hearing-impaired people and 6.5% in orthopaedically disabled people.

CONCLUSIONS

Educational interventions on nutrition and lifestyle can be effective considering the high prevalence of obesity in visually impaired people, the prevalence of weakness in orthopaedically disabled people and the risk related to the area in which body fat is localised even when body mass index is within the normal range. Training disabled people in sports appropriate to their disability type and building appropriate facilities for those sports might have a positive effect.

Ethnic admixture affects diabetes risk in native Hawaiians: the Multiethnic Cohort

BACKGROUND/OBJECTIVES

Obesity and diabetes rates are high in Native Hawaiians (NHs) who commonly have mixed ancestries. People of Asian ancestry experience a high risk of type 2 diabetes despite the relatively low body weight. We evaluated the impact of ethnic admixture on diabetes risk among NHs in the Multiethnic Cohort (MEC).

SUBJECTS/METHODS

On the basis of self-reports, 11 521 eligible men and women were categorized into NH/white, NH/other, NH alone, NH/Asian and the most common three ancestry admixture, NH/Chinese/white. Cox proportional hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated with the NH/white category as the reference group; covariates included known confounders-that is, body mass index (BMI), dietary and other lifestyle factors.

RESULTS

The NH alone category had the highest proportion of overweight and obese individuals and the NH/Asian category the lowest proportion. During 12 years of follow-up after cohort entry at 56 years, 2072 incident cases were ascertained through questionnaires and health plan linkages. All NH categories had higher HRs than the NH/white category before and after adjustment for BMI. In the fully adjusted models, the NH/Asian category showed the highest risk (HR=1.45; 95% CI: 1.27-1.65), followed by NH/other (HR=1.20; 95% CI: 1.03-1.39), NH/Chinese/white (HR=1.19; 95% CI: 1.04-1.37) and NH alone (HR=1.19; 95% CI: 1.03-1.37). The elevated risk by Asian admixture was more pronounced in normal weight than overweight/obese individuals.

CONCLUSIONS

These findings indicate that Asian admixture in NHs is associated with a higher risk for type 2 diabetes independent of known risk factors and suggest a role for ethnicity-related genetic factors in the development of this disease.

Nutrition and Diet as It Relates to Health and Well-Being of Native Hawaiian Kūpuna (Elders): A Systematic Literature Review

PURPOSE

The key to improving the health and well-being of Native Hawaiians is to understand the historical events that have caused change to their diet and nutrition, and identify the connection between food, life, and the land. The purpose of this article is to (a) present a review of the literature addressing nutrition and diet as it relates to health and well-being of Native Hawaiian kūpuna (elders) and (b) identify limitations and gaps to promote future research.

DESIGN

This systematic literature review focused on 29 studies.

FINDINGS

Native Hawaiians have the highest body mass index levels, highest daily energy (kilocalorie) intake, and lowest multivitamin use. They have the highest prevalence of diabetes and hypertension compared with Whites. Traditional Hawaiian diet programs and family support were beneficial to improving health and well-being.

CONCLUSION

Future research of traditional Hawaiian diet programs and revitalization of the culture may lead to improving the health and well-being of Native Hawaiians.

"Can't We Just Have Some Sazón?" Student, Family, and Staff Perspectives on a New School Food Program at a Boston High School

BACKGROUND

In September 2013, a Massachusetts high school launched a nutrition program in line with 2013 United States Department of Agriculture requirements. We sought to understand attitudes of stakeholders toward the new program.

METHODS

We employed community-based participatory research methods in a qualitative evaluation of the food program at the school, where 98% of students are students of color and 86% qualify for free/reduced lunch. We conducted 4 student (N = 32), 2 parent (N = 10), 1 faculty/staff focus group (N = 14), and interviews with school leadership (N = 3).

RESULTS

A total of 10 themes emerged from focus groups and interviews, in 3 categories--impressions of the food (insufficient portion size, dislike of the taste, appreciation of the freshness, increased unhealthy food consumption outside school), impact on learning (learning what's healthy, the program's innovativeness, control versus choice), and concerns about stakeholder engagement (lack of student/family engagement, culturally incompatible foods). A representative comment was: "You need something to hold them from 9 to 5, because if they are hungry, McDonald's is right there."

CONCLUSION

Stakeholders appreciated the educational value of the program but stakeholder dissatisfaction may jeopardize its success. Action steps could include incorporating culturally appropriate recipes in the school's menus and working with local restaurants to promote healthier offerings.

Formation of short chain fatty acids by the gut microbiota and their impact on human metabolism

The formation of SCFA is the result of a complex interplay between diet and the gut microbiota within the gut lumen environment. The discovery of receptors, across a range of cell and tissue types for which short chain fatty acids SCFA appear to be the natural ligands, has led to increased interest in SCFA as signaling molecules between the gut microbiota and the host. SCFA represent the major carbon flux from the diet through the gut microbiota to the host and evidence is emerging for a regulatory role of SCFA in local, intermediary and peripheral metabolism. However, a lack of well-designed and controlled human studies has hampered our understanding of the significance of SCFA in human metabolic health. This review aims to pull together recent findings on the role of SCFA in human metabolism to highlight the multi-faceted role of SCFA on different metabolic systems.

Formation of short chain fatty acids by the gut microbiota and their impact on human metabolism

The formation of SCFA is the result of a complex interplay between diet and the gut microbiota within the gut lumen environment. The discovery of receptors, across a range of cell and tissue types for which short chain fatty acids SCFA appear to be the natural ligands, has led to increased interest in SCFA as signaling molecules between the gut microbiota and the host. SCFA represent the major carbon flux from the diet through the gut microbiota to the host and evidence is emerging for a regulatory role of SCFA in local, intermediary and peripheral metabolism. However, a lack of well-designed and controlled human studies has hampered our understanding of the significance of SCFA in human metabolic health. This review aims to pull together recent findings on the role of SCFA in human metabolism to highlight the multi-faceted role of SCFA on different metabolic systems.

Imbalanced insulin action in chronic over nutrition: Clinical harm, molecular mechanisms, and a way forward

The growing worldwide prevalence of overnutrition and underexertion threatens the gains that we have made against atherosclerotic cardiovascular disease and other maladies. Chronic overnutrition causes the atherometabolic syndrome, which is a cluster of seemingly unrelated health problems characterized by increased abdominal girth and body-mass index, high fasting and postprandial concentrations of cholesterol- and triglyceride-rich apoB-lipoproteins (C-TRLs), low plasma HDL levels, impaired regulation of plasma glucose concentrations, hypertension, and a significant risk of developing overt type 2 diabetes mellitus (T2DM). In addition, individuals with this syndrome exhibit fatty liver, hypercoagulability, sympathetic overactivity, a gradually rising set-point for body adiposity, a substantially increased risk of atherosclerotic cardiovascular morbidity and mortality, and--crucially--hyperinsulinemia. Many lines of evidence indicate that each component of the atherometabolic syndrome arises, or is worsened by, pathway-selective insulin resistance and responsiveness (SEIRR). Individuals with SEIRR require compensatory hyperinsulinemia to control plasma glucose levels. The result is overdrive of those pathways that remain insulin-responsive, particularly ERK activation and hepatic de-novo lipogenesis (DNL), while carbohydrate regulation deteriorates. The effects are easily summarized: if hyperinsulinemia does something bad in a tissue or organ, that effect remains responsive in the atherometabolic syndrome and T2DM; and if hyperinsulinemia might do something good, that effect becomes resistant. It is a deadly imbalance in insulin action. From the standpoint of human health, it is the worst possible combination of effects. In this review, we discuss the origins of the atherometabolic syndrome in our historically unprecedented environment that only recently has become full of poorly satiating calories and incessant enticements to sit. Data are examined that indicate the magnitude of daily caloric imbalance that causes obesity. We also cover key aspects of healthy, balanced insulin action in liver, endothelium, brain, and elsewhere. Recent insights into the molecular basis and pathophysiologic harm from SEIRR in these organs are discussed. Importantly, a newly discovered oxide transport chain functions as the master regulator of the balance amongst different limbs of the insulin signaling cascade. This oxide transport chain--abbreviated 'NSAPP' after its five major proteins--fails to function properly during chronic overnutrition, resulting in this harmful pattern of SEIRR. We also review the origins of widespread, chronic overnutrition. Despite its apparent complexity, one factor stands out. A sophisticated junk food industry, aided by subsidies from willing governments, has devoted years of careful effort to promote overeating through the creation of a new class of food and drink that is low- or no-cost to the consumer, convenient, savory, calorically dense, yet weakly satiating. It is past time for the rest of us to overcome these foes of good health and solve this man-made epidemic.

Effects of targeted delivery of propionate to the human colon on appetite regulation, body weight maintenance and adiposity in overweight adults

OBJECTIVE

The colonic microbiota ferment dietary fibres, producing short chain fatty acids. Recent evidence suggests that the short chain fatty acid propionate may play an important role in appetite regulation. We hypothesised that colonic delivery of propionate would increase peptide YY (PYY) and glucagon like peptide-1 (GLP-1) secretion in humans, and reduce energy intake and weight gain in overweight adults.

DESIGN

To investigate whether propionate promotes PYY and GLP-1 secretion, a primary cultured human colonic cell model was developed. To deliver propionate specifically to the colon, we developed a novel inulin-propionate ester. An acute randomised, controlled cross-over study was used to assess the effects of this inulin-propionate ester on energy intake and plasma PYY and GLP-1 concentrations. The long-term effects of inulin-propionate ester on weight gain were subsequently assessed in a randomised, controlled 24-week study involving 60 overweight adults.

RESULTS

Propionate significantly stimulated the release of PYY and GLP-1 from human colonic cells. Acute ingestion of 10 g inulin-propionate ester significantly increased postprandial plasma PYY and GLP-1 and reduced energy intake. Over 24 weeks, 10 g/day inulin-propionate ester supplementation significantly reduced weight gain, intra-abdominal adipose tissue distribution, intrahepatocellular lipid content and prevented the deterioration in insulin sensitivity observed in the inulin-control group.

CONCLUSIONS

These data demonstrate for the first time that increasing colonic propionate prevents weight gain in overweight adult humans.

TRIAL REGISTRATION NUMBER

NCT00750438.

Racial and ethnic disparities in the impact of obesity on breast cancer risk and survival: a global perspective

Obesity is a global concern, affecting both developed and developing countries. Although there are large variations in obesity and breast cancer rates worldwide and across racial/ethnic groups, most studies evaluating the impact of obesity on breast cancer risk and survival have been conducted in non-Hispanic white women in the United States or Europe. Given the known racial/ethnic differences in tumor hormone receptor subtype distribution, obesity prevalence, and risk factor profiles, we reviewed published data for women of African, Hispanic, and Asian ancestry in the United States and their countries of origin. Although the data are limited, current evidence suggests a stronger adverse effect of obesity on breast cancer risk and survival in women of Asian ancestry. For African Americans and Hispanics, the strength of the associations appears to be more comparable to that of non-Hispanic whites, particularly when accounting for subtype and menopausal status. Central obesity seems to have a stronger impact in African-American women than general adiposity as measured by body mass index. International data from countries undergoing economic transition offer a unique opportunity to evaluate the impact of rapid weight gain on breast cancer. Such studies should take into account genetic ancestry, which may help elucidate differences in associations between ethnically admixed populations. Overall, additional large studies that use a variety of adiposity measures are needed, because the current evidence is based on few studies, most with limited statistical power. Future investigations of obesity biomarkers will be useful to understand possible racial/ethnic biological differences underlying the complex association between obesity and breast cancer development and progression.

Prebiotics Modulate the Effects of Antibiotics on Gut Microbial Diversity and Functioning in Vitro

Intestinal bacteria carry out many fundamental roles, such as the fermentation of non-digestible dietary carbohydrates to produce short chain fatty acids (SCFAs), which can affect host energy levels and gut hormone regulation. Understanding how to manage this ecosystem to improve human health is an important but challenging goal. Antibiotics are the front line of defence against pathogens, but in turn they have adverse effects on indigenous microbial diversity and function. Here, we have investigated whether dietary supplementation—another method used to modulate gut composition and function—could be used to ameliorate the side effects of antibiotics. We perturbed gut bacterial communities with gentamicin and ampicillin in anaerobic batch cultures in vitro. Cultures were supplemented with either pectin (a non-fermentable fibre), inulin (a commonly used prebiotic that promotes the growth of beneficial bacteria) or neither. Although antibiotics often negated the beneficial effects of dietary supplementation, in some treatment combinations, notably ampicillin and inulin, dietary supplementation ameliorated the effects of antibiotics. There is therefore potential for using supplements to lessen the adverse effects of antibiotics. Further knowledge of such mechanisms could lead to better therapeutic manipulation of the human gut microbiota.

Dietary Patterns of Young Females and Their Association With Waist Circumference as a Health Index in Northwest of Iran, 2007

Background:

Despite the higher prevalence of overweight and obesity among young people in western countries, the 50th and 95th percentile ranks for waist circumference in the Iranian young Females are higher than those of the western ones.

Objectives:

Identifying major dietary patterns in Iranian young females, which associate with central obesity, can probably explain the difference between Iranian young females’ pattern and those of their western peers regarding obesity.

Patients and Methods:

In the current cross-sectional study, a total of 257 young females aged 11 - 15 years old from Talaat Intelligent Guidance School, Tabriz, Iran (2007) were selected for the study using non-probability simple sampling method. Then, usual dietary intakes of all subjects were evaluated by a food frequency questionnaire and anthropometric measurements such as weight, height, waist circumference, and Body Mass Index (BMI) using the standard protocols. Data were analyzed by inferential statistics (One-way ANOVA, Tukey test for Post-Hoc Analysis, Chi-square test, age-adjusted means, analysis of covariance with Bonferroni correction, correlation and partial correlation) by SPSS software.

Results:

In the current study, six major dietary patterns were extracted using factor analysis method. Before and after controlling the age, subjects in the upper tertile of the Iranian Central Obesity Making Dietary Pattern (rich in cruciferous vegetables, green leafy vegetables, soft drinks, tomatoes, other vegetables and vegetable oils) had larger waist circumference in comparison with the ones in the lower tertile (before controlling for age: 64.2 ± 9 vs. 61.6 ± 7 P = 0.03; after: 64.5 ± 0.8 vs. 61.5 ± 0.8, P = 0.009). However in lacto vegetarian dietary pattern (rich in legumes, potato, other vegetables, dough, high-fat dairy products and margarine), individuals in the upper tertile had significantly lower weight, waist circumference and body mass index (BMI) in comparison with the ones in the lower tertile (weight: 44.9 ± 9.3 vs. 51.4 ± 10.6, P < 0.01; WC: 59.9 ± 8 vs. 64 ± 7.9, P < 0.01; BMI: 18.6 ± 3.1 vs. 20.6 ± 3.5, P < 0.01).

Conclusions:

The current study findings suggest that the Iranian Central Obesity Making Dietary Pattern is directly associated with waist circumference (marker of central obesity), while lacto vegetarian dietary pattern is reversely associated with weight, waist circumference and BMI. Special obesity pattern in Iranian young females can be justified by Iranian Central Obesity Making Dietary Pattern”.

Differences in IGF-axis protein expression and survival among multiethnic breast cancer patients

There is limited knowledge about the biological basis of racial/ethnic disparities in breast cancer outcomes. Aberrations in IGF signaling induced by obesity and other factors may contribute to these disparities. This study examines the expression profiles of the insulin-like growth factor (IGF)-axis proteins and the association with breast cancer survival across a multiethnic population. We examined the expression profiles of the IGF1, IGF1R, IGFBP2 (IGF-binding proteins), and IGFBP3 proteins in breast tumor tissue and their relationships with all-cause and breast cancer-specific survival up to 17 years postdiagnosis in a multiethnic series of 358 patients in Hawaii, USA. Native Hawaiians, Caucasians, and Japanese were compared. Covariates included demographic and clinical factors and ER/PR/HER2 (estrogen receptor/progesterone receptor/human epidermal growth factor receptor-2) status. In Native Hawaiian patients, IGFBP2 and IGFBP3 expression were each independently associated with overall and breast cancer mortality (IGFB2: HR_mort = 10.96, 95% CI: 2.18–55.19 and HR_mort = 35.75, 95% CI: 3.64–350.95, respectively; IGFBP3: HR_mort = 5.16, 95% CI: 1.27–20.94 and HR_mort = 8.60, 95% CI: 1.84–40.15, respectively). IGF1R expression was also positively associated with all-cause mortality in Native Hawaiians. No association of IGF-axis protein expression and survival was observed in Japanese or Caucasian patients. The interaction of race/ethnicity and IGFBP3 expression on mortality risk was significant. IGF-axis proteins may have variable influence on breast cancer progression across different racial/ethnic groups. Expression of binding proteins and receptors in breast tumors may influence survival in breast cancer patients by inducing aberrations in IGF signaling and/or through IGF-independent mechanisms. Additional studies to evaluate the role of the IGF-axis in breast cancer are critical to improve targeted breast cancer treatment strategies.

Control of appetite and energy intake by SCFA: what are the potential underlying mechanisms?

In recent years, there has been a renewed interest in the role of dietary fibre in obesity management. Much of this interest stems from animal and human studies which suggest that an increased intake of fermentable fibre can suppress appetite and improve weight management. A growing number of reports have demonstrated that the principal products of colonic fermentation of dietary fibre, SCFA, contribute to energy homeostasis via effects on multiple cellular metabolic pathways and receptor-mediated mechanisms. In particular, over the past decade it has been identified that a widespread receptor system exists for SCFA. These G-protein-coupled receptors, free fatty acid receptor (FFAR) 2 and FFAR3 are expressed in numerous tissue sites, including the gut epithelium and adipose tissue. Investigations using FFAR2- or FFAR3-deficient animal models suggest that SCFA-mediated stimulation of these receptors enhances the release of the anorectic hormones peptide tyrosine tyrosine and glucagon-like peptide-1 from colonic L cells and leptin from adipocytes. In addition, the SCFA acetate has recently been shown to have a direct role in central appetite regulation. Furthermore, the SCFA propionate is a known precursor for hepatic glucose production, which has been reported to suppress feeding behaviour in ruminant studies through the stimulation of hepatic vagal afferents. The present review therefore proposes that an elevated colonic production of SCFA could stimulate numerous hormonal and neural signals at different organ and tissue sites that would cumulatively suppress short-term appetite and energy intake.

[Dietary fiber--adequate intake and effects on metabolism health]

The positive effects of dietary fiber are related, in part, to the fact that a portion of the fermentation of components takes place in the large intestine, which has an impact on the speed of digestion, pH of the colon, and production of by-products with important physiological functions. Individuals with high fiber intake seem to have lower risk of developing coronary artery disease, hypertension, obesity, diabetes, and colon cancer. The increase in fiber intake reduces serum cholesterol, improves blood glucose in patients with diabetes, reduces body weight, and is associated with lower serum ultrasensitive C-reactive protein. Increased fiber intake and intake of more fiber than the currently recommended level (14 g/1,000 kcal) may provide greater health benefits, including reducing low-grade inflammation.

Measuring oral fatty acid thresholds, fat perception, fatty food liking, and papillae density in humans

Emerging evidence from a number of laboratories indicates that humans have the ability to identify fatty acids in the oral cavity, presumably via fatty acid receptors housed on taste cells. Previous research has shown that an individual's oral sensitivity to fatty acid, specifically oleic acid (C18:1) is associated with body mass index (BMI), dietary fat consumption, and the ability to identify fat in foods. We have developed a reliable and reproducible method to assess oral chemoreception of fatty acids, using a milk and C18:1 emulsion, together with an ascending forced choice triangle procedure. In parallel, a food matrix has been developed to assess an individual's ability to perceive fat, in addition to a simple method to assess fatty food liking. As an added measure tongue photography is used to assess papillae density, with higher density often being associated with increased taste sensitivity.

Ethics and Community Involvement in Syntheses Concerning American Indian, Alaska Native, or Native Hawaiian Health: A Systematic Review

BACKGROUND

The objective of the research was to review reporting of ethical concerns and community involvement in peer-reviewed systematic reviews or meta-analyses concerning American Indian, Alaska Native, or Native Hawaiian (AI/AN/NH) health.

METHODS

Text words and indexed vocabulary terms were used to query PubMed, Embase, Cochrane Library, and the Native Health Database for systematic reviews or meta-analyses concerning AI/AN/NH health published in peer-reviewed journals, followed by a search through reference lists. Each article was abstracted by two independent reviewers; results were discussed until consensus was reached.

RESULTS

We identified 107 papers published from 1986-2012 that were primarily about AI/AN/NH health or presented findings separately for AI/AN/NH communities. Two reported seeking indigenous reviewer feedback; none reported seeking input from tribes and communities. Approximately 7% reported on institutional review board (IRB) approval of included studies, 5% reported on tribal approval, and 4% referenced the sovereignty of AI/AN tribes. Approximately 63% used evidence from more than one AI/AN/NH population study, and 28% discussed potential benefits to communities from the synthesis research.

CONCLUSIONS

Reporting of ethics and community involvement are not prominent. Systematic reviews and meta-analyses making community-level inferences may pose risks to communities. Future systematic reviews and meta-analyses should consider ethical and participatory dimensions of research.

High-fiber rye diet increases ileal excretion of energy and macronutrients compared with low-fiber wheat diet independent of meal frequency in ileostomy subjects

Background

Whole-grain foods and cereal dietary fiber intake is associated with lower body weight. This may partly result from lower energy utilization of high-fiber diets.

Objective

In the present study, the impact on ileal excretion of energy and macronutrients in response to a rye bread high-fiber diet compared to a refined wheat low-fiber diet was investigated. Furthermore, the effect of meal frequency on apparent absorption of nutrients was studied for the first time.

Design

Ten participants that had undergone ileostomy consumed standardized iso-caloric diets, including low-fiber wheat bread (20 g dietary fiber per day) for 2 weeks followed by high-fiber rye bread (52 g dietary fiber per day) for 2 weeks. The diets were consumed in an ordinary (three meals per day) and a nibbling (seven meals per day) meal frequency in a cross-over design. Ileal effluents were collected during 24 h at the third day of each of the four dietary periods and analyzed for gross energy and nutrient contents.

Results

The results showed that intake of rye bread high-fiber diet compared to the refined wheat low-fiber diet caused an increase in ileal excretion of energy and macronutrients. The effect was independent of meal frequency. This suggests that a high intake of rye may result in lower availability of macronutrients for small intestinal digestion and absorption. A regular intake of rye may therefore have implications for weight management.

Differential association between adherence to nutritional recommendations and body weight status across educational levels: a cross-sectional study

OBJECTIVE

The impact of diet quality and physical activity (PA) on weight might be different according to socioeconomic status. Our aim was to estimate associations between adherence to nutritional guidelines and BMI and the interaction with socioeconomic characteristics.

METHODS

A total of 11,931 men and 39,737 women from the NutriNet-Santé cohort (France, 2009-2012) were included in this cross-sectional analysis. The association between PNNS-GS (a score estimating adherence to French nutritional guidelines) and BMI was assessed by multivariate linear regression. A modified score (mPNNS-GS) separating diet quality from PA was also used.

RESULTS

BMI, overweight and obesity displayed an inverse gradient from less to more educated groups, whereas PNNS-GS increased. A higher PNNS-GS was associated with a lower BMI, more importantly in the less educated: BMI decrease ranged from -1.1% in less educated to -0.7% in more educated men and from -0.6% to -0.3% in women. The effect of mPNNS-GS and PA in particular was also stronger among less educated subjects.

CONCLUSION

Overall, better adherence to nutritional recommendations was inversely associated with BMI, and this association was stronger in the less educated groups. This suggests that nutritional policies should still concentrate on promoting access to a healthier diet and PA, especially among less educated individuals.

Associação entre consumo de alimentos embutidos e obesidade em um estudo de base populacional de nipo-brasileiros

OBJETIVO: Investigar a associação entre consumo de alimentos embutidos e obesidade generalizada, abdominal e generalizada com abdominal em nipo-brasileiros de Bauru, SP. SUJEITOS E MÉTODOS: Quatrocentos e quarenta e três mulheres e 329 homens nipo-brasileiros não miscigenados (≥ 30 anos) foram avaliados em estudo transversal de base populacional. Para o diagnóstico de obesidade, foram empregados os critérios da Organização Mundial da Saúde para asiáticos. A ingestão de alimentos foi avaliada por meio de questionário de frequência alimentar validado. A ingestão foi estratificada em terços para análise. RESULTADOS: Nos homens, a ingestão de colesterol e alimentos embutidos mostrou-se positivamente associada à obesidade generalizada com abdominal quando o primeiro terço de ingestão foi comparado ao último, após ajustes (OR 2,97; IC95% 1,13-7,78). Em mulheres, somente o grupo das carnes vermelhas associou-se à obesidade geral com abdominal após ajustes (OR 0,47; IC95% 0,23-0,96). CONCLUSÃO: Ingestão elevada de alimentos embutidos associou-se à obesidade generalizada com adiposidade abdominal em homens nipo-brasileiros, mas não em mulheres.

Advances in RNA interference technology and its impact on nutritional improvement, disease and insect control in plants

This review highlights the advances in the knowledge of RNA interference (RNAi) and discusses recent progress on the functionality of different components RNAi machinery operating in the organisms. The silencing of genes by RNA interference has become the technology of choice for investigation of gene functions in different organisms. The refinement in the knowledge of the endogenous RNAi pathways in plants along with the development of new strategies and applications for the improvement of nutritional value of important agricultural crops through suppression of genes in different plants have opened new vistas for nutritional security. The improvement in the nutritional status of the plants and reduction in the level of toxins or antinutrients was desired for long, but the available technology was not completely successful in achieving the tissue specific regulation of some genes. In the recent years, a number of economically important crop plants have been tested successfully for improving plant nutritional value through metabolic engineering using RNAi. The implications of this technology for crop improvement programs, including nutritional enrichment, reduction of antinutrients, disease, and insect control have been successfully tested in variety of crops with commercial considerations. The enhancement of the nutraceutical traits for the desired health benefits in common crop plants through manipulation of gene expression has been elaborated in this article. The tremendous potential with RNAi technology is expected to revolutionize the modern agriculture for meeting the growing challenges is discussed.

Prepregnancy obesity trends among low-income women, United States, 1999-2008

There is limited data on prepregnancy obesity trends specifically among low-income women, a population at high risk for obstetric complications. Using the Pregnancy Nutrition Surveillance System, we assessed prepregnancy obesity [body mass index (BMI) ≥ 30 kg/m(2)] trends among women who participated in the Supplemental Nutrition Program for Women, Infants, and Children in 1999, 2004, and 2008. Prepregnancy BMI was calculated using measured height and self-reported prepregnancy weight. We report unadjusted contributor (state, territory or Indian tribal organization) specific trends, and both unadjusted and adjusted overall trends, to account for changes in maternal age and race-ethnic distributions, using 1999 as the referent. Of the 27 contributors in 1999, 2 had a prepregnancy obesity prevalence <20%, and 1 had a prevalence ≥ 30%. Of the 35 contributors in 2008, none had a prepregnancy obesity prevalence <20%, and 14 had a prevalence ≥ 30%. From 1999 to 2008, the overall prevalence of prepregnancy obesity increased among all racial-ethnic groups, except among American Indian/Alaskan Natives, where it remained high, but stable. Overall prepregnancy obesity increased most rapidly among Hispanics, and remained stable from 2004 to 2008 among non-Hispanic blacks. In 2008, prevalence was highest among American Indian/Alaskan Natives (36.1%) and lowest among Asians/Pacific Islanders (10.8%). The adjusted prepregnancy obesity prevalence increased from 24.8% in 1999 to 28.3% in 2008, a relative increase of 14.1%. Prepregnancy obesity among low-income women increased from 1999 to 2008 and varied by race-ethnicity. These data can be used by obesity prevention programs to better target high-risk women.

Isocaloric intake of a high-fat diet promotes insulin resistance and inflammation in Wistar rats

The aim of this study was to investigate the effect of isocaloric intake from a high-fat diet (HFD) on insulin resistance and inflammation in rats. Male Wistar rats were fed on an HFD (n = 12) or control diet (n = 12) for 12 weeks. Subsequently, all animals were euthanized, and blood glucose, insulin, free fatty acids, C-reactive protein, lipid profile, cytokines and hepatic-enzyme activity were determined. Carcass chemical composition was also analyzed. During the first and the twelfth weeks of the experimental protocol, the oral glucose tolerance test and insulin tolerance test were performed and demonstrated insulin resistance (P < 0.05) in the HFD group. Although food intake (g) was lower (P < 0.05) in the HFD group compared with the control group, the concentration of total cholesterol, low-density lipoprotein, C-reactive protein and liver weight were all significantly higher. The kinase inhibitor of κB, c-Jun N-terminal kinase and protein kinase B expressions were determined in the liver and skeletal muscle. After an insulin stimulus, the HFD group demonstrated decreased (P = 0.05) hepatic protein kinase B expression, whereas the kinase inhibitor of κB phospho/total ratio was elevated in the HFD muscle (P = 0.02). In conclusion, the isocaloric intake from the HFD induced insulin resistance, associated with impaired insulin signalling in the liver and an inflammatory response in the muscle.

Prebiotics and the health benefits of fiber: current regulatory status, future research, and goals

First defined in the mid-1990s, prebiotics, which alter the composition and activity of gastrointestinal (GI) microbiota to improve health and well-being, have generated scientific and consumer interest and regulatory debate. The Life Sciences Research Organization, Inc. (LSRO) held a workshop, Prebiotics and the Health Benefits of Fiber: Future Research and Goals, in February 2011 to assess the current state of the science and the international regulatory environment for prebiotics, identify research gaps, and create a strategy for future research. A developing body of evidence supports a role for prebiotics in reducing the risk and severity of GI infection and inflammation, including diarrhea, inflammatory bowel disease, and ulcerative colitis as well as bowel function disorders, including irritable bowel syndrome. Prebiotics also increase the bioavailability and uptake of minerals and data suggest that they reduce the risk of obesity by promoting satiety and weight loss. Additional research is needed to define the relationship between the consumption of different prebiotics and improvement of human health. New information derived from the characterization of the composition and function of different prebiotics as well as the interactions among and between gut microbiota and the human host would improve our understanding of the effects of prebiotics on health and disease and could assist in surmounting regulatory issues related to prebiotic use.

Adiponectin gene SNP276 variants and central obesity confer risks for hyperglycemia in indigenous Taiwanese

This cross-sectional study analyzed the effects of two single nucleotide polymorphisms (SNP) of the adiponectin gene, SNP45 and SNP276, on hyperglycemia in indigenous Taiwanese, and whether central obesity modulates the effects of these SNPs. Overall, 550 indigenous Taiwanese were recruited for this cross-sectional study. The subjects were categorized into a hyperglycemic group if fasting plasma glucose was > 126 mg/dL (n = 88) or the control group if fasting plasma glucose was < 100 mg/dL (n = 462). The SNP276 TT homozygote carried greater hyperglycemia risk than SNP276 GG [odds ratio (OR) = 2.67, 95% confidence interval (CI) = 1.05-6.78], but not heterozygote (OR = 1.54, 95% CI = 0.95-2.50). SNP45 T > G was not associated with hyperglycemia risk. In multivariate-adjusted modeling, we found a significant relationship between SNP276 T carriers (GT + TT) (OR = 2.06, 95% CI = 1.10-3.88) and central obesity (OR = 4.50, 95% CI = 1.91-10.61) with hyperglycemia. Compared with non-central-obese carriers of SNP276 GG, non-central-obese SNP276 T carriers, and central obese subjects with SNP276 GG and SNP276 T carriers had 5.50, 8.31 and 13.76-fold, respectively, higher risks for hyperglycemia; obese carriers of the T-containing variants experienced a combined risk for hyperglycemia. Furthermore, the hyperglycemic risks were more pronounced in leaner (non-central-obese) individuals carrying the T variant than the central-obese individuals. The adiponectin SNP276 T variant and central obesity had independent and additive effects on hyperglycemia risks. These findings may provide valuable information regarding preventive strategies that might be useful to prevent or treat diabetes and its related complications.

Glycaemic index, appetite and body weight

Much interest has been focused on the relationship between glycaemic index and body-weight loss, some of which is fueled by popular media. However, there is a number of potential mechanisms that could be triggered by reducing the glycaemic index of the carbohydrate consumed in the diet. For example, the effect of foods on the gastrointestinal tract and the effect on blood glucose both could lead to potential appetite effects. Acute meal studies seem to point to an effect of glycaemic index on appetite regulation. However, the results of longer-term studies of weight loss are not as clear. In the present review a possible reason for this variation in outcome from the weight-loss studies will be discussed. The present review focuses on the possibility that the fermentable fibre content of the low-glycaemic-index diet may be important in weight-loss efficacy. A novel receptor that binds SCFA, the products of carbohydrate fermentation, has recently been described on the enteroendocrine L-cell in the colon. This cell releases a number of anorectic hormones and could offer an explanation of the appetite suppressant effects of fermentable carbohydrates. It could also explain the variability in the results of glycaemic-index weight-loss studies.

Increasing doses of fiber do not influence short-term satiety or food intake and are inconsistently linked to gut hormone levels

Background

People who eat more fiber often have a lower body weight than people who eat less fiber. The mechanism for this relationship has been explained, in part, by increased satiety, which may occur as a result of changes in appetite-suppressing gut hormone levels, and decreases in food intake at subsequent meals.

Objective

We hypothesized that increasing doses of mixed fiber, consumed in muffins for breakfast, would proportionally influence satiety, gut hormone levels, and subsequent food intake.

Design

This was a randomized, double-blind, crossover study. Healthy men (n=10) and women (n=10) with a BMI of 24±2 (mean±SEM) participated in this study. Fasting subjects consumed a muffin with 0, 4, 8, or 12 g of mixed fibers and approximately 500 kcal. Visual analog scales rated hunger and satiety for 3 h; blood was drawn to measure ghrelin, glucagon-like peptide-1 (GLP-1), and peptide YY_3–36 (PYY_3–36) at various intervals; and food intake was measured at an ad libitum lunch.

Results

Responses to satiety-related questions did not differ among treatments. However, despite lack of differences in satiety, gut hormone levels differed among treatments. Ghrelin was higher after the 12 g fiber dose than after the 4 and 8 g fiber doses. GLP-1 was higher after the 0 g fiber dose than after the 12 and 4 g fiber doses, and PYY_3–36 did not differ among fiber doses. Food intake was also indistinguishable among doses.

Conclusion

Satiety, gut hormone response, and food intake did not change in a dose-dependent manner after subjects consumed 0, 4, 8, and 12 g of mixed fiber in muffins for breakfast.

Free fatty acid receptor 2 and nutrient sensing: a proposed role for fibre, fermentable carbohydrates and short-chain fatty acids in appetite regulation

The way in which the composition of the diet may affect appetite, food intake and body weight is now receiving considerable attention in a bid to halt the global year-on-year rise in obesity prevalence. Epidemiological evidence suggests that populations who follow a fibre-rich, traditional diet are likely to have a lower body weight and improved metabolic parameters than their Western-diet counterparts. The colonic effects of fibre, and more specifically the SCFA that the fermentation process produces, may play a role in maintaining energy homeostasis via their action on the G-coupled protein receptor free fatty acid receptor 2 (FFA2; formerly GPR43). In the present review, we summarise the evidence for and against the role of FFA2 in energy homeostasis circuits and the possible ways that these could be exploited therapeutically. We also propose that the decline in fibre content of the diet since the Industrial Revolution, particularly fermentable fractions, may have resulted in the FFA2-mediated circuits being under-utilised and hence play a role in the current obesity epidemic.

Gestational diabetes mellitus: all Asians are not alike

OBJECTIVE

To estimate the prevalence of gestational diabetes mellitus (GDM) prevalence estimates for subgroups of US Asian and Pacific Islander (API) women by using data from 2005 and 2006 birth certificates.

METHODS

Using 2005-2006 natality files from states that implemented the revised 2003 US birth certificate, which differentiates between GDM and preexisting diabetes (2005: 12 states; 2006: 19 states), we calculated age-adjusted GDM prevalence estimates for API mothers who delivered singleton infants.

RESULTS

Among 3,108,877 births, US APIs had a substantially higher age-adjusted prevalence of GDM (6.3%) than whites (3.8%), blacks (3.5%), or Hispanics (3.6%). Among API subgroups, age-adjusted GDM prevalence varied significantly, from 3.7% among women of Japanese descent to 8.6% among women of Asian Indian descent. Foreign-born APIs had significantly higher GDM rates than US-born APIs except among women of Japanese and Korean ancestry.

CONCLUSION

Overall, US API women have the highest risk for GDM among all US racial/ethnic groups. However, APIs are a heterogeneous group by genetic background, culture, and diet and other lifestyle behaviors. Our findings imply that, whenever possible, API subgroups should be evaluated separately in health research.

Diabetes incidence based on linkages with health plans: the multiethnic cohort

OBJECTIVE

Using the Hawaii component of the Multiethnic Cohort (MEC), we estimated diabetes incidence among Caucasians, Japanese Americans, and Native Hawaiians.

RESEARCH DESIGN AND METHODS

After excluding subjects who reported diabetes at baseline or had missing values, 93,860 cohort members were part of this analysis. New case subjects were identified through a follow-up questionnaire (1999-2000), a medication questionnaire (2003-2006), and linkage with two major health plans (2007). We computed age-standardized incidence rates and estimated hazard ratios (HRs) for ethnicity, BMI, education, and combined effects of these variables using Cox regression analysis.

RESULTS

After a total follow-up time of 1,119,224 person-years, 11,838 incident diabetic case subjects were identified with an annual incidence rate of 10.4 per 1,000 person-years. Native Hawaiians had the highest rate with 15.5, followed by Japanese Americans with 12.5, and Caucasians with 5.8 per 1,000 person-years; the adjusted HRs were 2.65 for Japanese Americans and 1.93 for Native Hawaiians. BMI was positively related to incidence in all ethnic groups. Compared with the lowest category, the respective HRs for BMIs of 22.0-24.9, 25.0-29.9, and > or =30.0 kg/m(2) were 2.10, 4.12, and 9.48. However, the risk was highest for Japanese Americans and intermediate for Native Hawaiians in each BMI category. Educational achievement showed an inverse association with diabetes risk, but the protective effect was limited to Caucasians.

CONCLUSIONS

Within this multiethnic population, diabetes incidence was twofold higher in Japanese Americans and Native Hawaiians than in Caucasians. The significant interaction of ethnicity with BMI and education suggests ethnic differences in diabetes etiology.

Effects of mild calorie restriction and high-intensity interval walking in middle-aged and older overweight Japanese

We investigated whether a combination of mild calorie restriction (MCR) and high-intensity interval walking (HIW) improved physical fitness more than HIW alone in middle-aged and older overweight Japanese (40-69years old, BMI23.6kg/m(2)). Forty-seven women and 16 men were divided into MCR+HIW and HIW groups. All subjects performed HIW: 5 sets of 3-min low-intensity walking (40% peak aerobic capacity for walking, VO(2peak)) and 3-min high-intensity walking (70% VO(2peak)) per day, 4days per week, for 16weeks while energy expenditure was monitored with a tri-axial accelerometer. The MCR+HIW group consumed meal replacement formula (240kcal): a mixture of low-carbohydrates and -fat and high-protein, for either lunch or dinner everyday and therefore, had approximately 87% of the energy intake of the HIW group during the intervention period. Although the HIW group showed improvements in BMI, blood pressure, and several blood chemicals, the MCR+HIW group had greater improvement. Moreover, the medical expenditure for the 6months including the intervention period was 59% lower in the MCR+HIW group than in the HIW group. Our strategy of a short-term combination of MCR and HIW may thus prevent lifestyle-associated diseases and improve health in middle-aged and older overweight Japanese.

Cardiometabolic health disparities in native Hawaiians and other Pacific Islanders

Elimination of health disparities in the United States is a national health priority. Cardiovascular disease, diabetes, and obesity are key features of what is now referred to as the "cardiometabolic syndrome," which disproportionately affects racial/ethnic minority populations, including Native Hawaiians and other Pacific Islanders (NHOPI). Few studies have adequately characterized the cardiometabolic syndrome in high-risk populations such as NHOPI. The authors systematically assessed the existing literature on cardiometabolic disorders among NHOPI to understand the best approaches to eliminating cardiometabolic health disparities in this population. Articles were identified from database searches performed in PubMed and MEDLINE from January 1998 to December 2008; 43 studies were included in the review. There is growing confirmatory evidence that NHOPI are one of the highest-risk populations for cardiometabolic diseases in the United States. Most studies found increased prevalences of diabetes, obesity, and cardiovascular risk factors among NHOPI. The few experimental intervention studies found positive results. Methodological issues included small sample sizes, sample bias, inappropriate racial/ethnic aggregation of NHOPI with Asians, and a limited number of intervention studies. Significant gaps remain in the understanding of cardiometabolic health disparities among NHOPI in the United States. More experimental intervention studies are needed to examine promising approaches to reversing the rising tide of cardiometabolic health disparities in NHOPI.

Secular trends in food patterns of Guatemalan consumers: new foods for old

BACKGROUND

Food patterns of population groups change and adapt under the influence of several factors, including those related to globalization, urbanization, and the nutrition transition.

OBJECTIVE

To document changes in food consumption and dietary patterns of Guatemalans, based on food surveys from the middle of the 20th century and the beginning of the 21st century.

METHODS

We accessed archival dietary data from surveys conducted in nine rural or semirural traditional Guatemalan communities in the 1950s and from two studies of nonindigenous Guatemalans and Guatemalans of Mayan descent conducted after 1998. The total number and types of food items and the nutrient intakes from the two eras were compared.

RESULTS

We identified 210 distinct food items across time, including 108 items consumed in traditional indigenous and nonindigenous Guatemalan communities ("old" foods), of which 72% were still consumed by nonindigenous Guatemalans and 76% were still consumed by Mayan Guatemalans. Processed foods represented only 11% of the items consumed in traditional Guatemalan communities but 30% of those consumed by nonindigenous Guatemalans and 25% of those consumed by Mayan Guatemalans. The proportions of carbohydrates, fats, and proteins as percentages of total energy were 79:9:12 among traditional Guatemalan communities, 67:20:13 among nonindigenous Guatemalans, and 61:27:12 among Mayan Guatemalans.

CONCLUSIONS

Changes in Guatemalan food patterns and in nutrient intakes are marked by increased food variety, at the expense of reduction in the consumption of nutrient-dense foods and increase in the consumption of processed foods. Such changes are consistent with those observed in other societies, where a combination of forces associated with demographic, epidemiologic, and nutritional transitions is occurring within the dynamics of urbanization and globalization phenomena that characterize contemporary times.

Relationship between needs driving eating occasions and eating behavior in midlife women

The purpose of this cross-sectional study was to determine the relationship between type of eating occasion based on need state segments experienced by 200 midlife women (46+/-6 years) and food group, nutrient, and energy intake. Women completed an Eating Occasion Questionnaire for 3 eating occasions over a 3-day period for which they maintained diet records. Cluster analysis segmented 559 eating occasions into six need states. Energy, total fat, and cholesterol consumption per occasion were highest in "routine family meal" occasions of which more than 60% were dinner and eaten at home with their children. The percentage of eating occasions in which fruits/vegetables were eaten was also highest in "routine family meal," followed by "healthy regimen." More than half of "indulgent escape" eating occasions occurred away from home and about one-third were experienced as a snack. Saturated fat and sweets intakes were the highest in the "indulgent escapes" occasions. Eating occasions experienced by women according to needs surrounding the occasion should be considered when developing tailored interventions to improve intake.

Macronutrient distribution over a period of 23 years in relation to energy intake and body fatness

The distribution of the four macronutrients is associated with energy intake and body fatness according to short-term interventions. The present study involves macronutrient distribution in relation to energy intake and body fatness over a period of 23 years in individuals who have ad libitum access to food. Eight follow-up measurements have been performed in 168 men and 182 women who participate in the Amsterdam Growth and Health Longitudinal Study. From the age of 13 years onwards, dietary intake, physical activity and the thickness of four skinfolds have been assessed. Body fatness was assessed using dual-energy X-ray absorptiometry at the age of 36 years. Generalised estimating equation regression analyses showed that energy percentages (En%) from protein and (in men) carbohydrates were inversely related to energy intake, while the En% from fat was positively related with energy intake. The men and women with high body fatness at the age of 36 years had a 1 En% higher protein intake, and the women with high body fatness had a 2 En% lower alcohol intake at the age of 32 and 36 years. The apparent inconsistent relationships between protein and energy intake and protein and body fatness can in women be explained by reverse causation and underreporting, as in women, low energy intake could not be explained by low physical activity. In conclusion, high intake of protein and (in men) carbohydrate, and low intake of fat are inversely related to total energy intake. High body fatness at the age of 36 years is related to a higher protein intake and, in women, to a lower alcohol intake.

Obesity and risk of colorectal cancer: a meta-analysis of 31 studies with 70,000 events

BACKGROUND

Colorectal cancer is the second most common cause of death and illness in developed countries. Previous reviews have suggested that obesity may be associated with 30% to 60% greater risk of colorectal cancer, but little consideration was given to the possible effect of publication bias on the reported association.

METHODS

Relevant studies were identified through EMBASE and MEDLINE. Studies were included if they had published quantitative estimates of the association between general obesity [defined here as body mass index (BMI) > or = 30 kg/m(2)] and central obesity (measured using waist circumference) and colorectal cancer. Random-effects meta-analyses were done, involving 70,000 cases of incident colorectal cancer from 31 studies, of which 23 were cohort studies and 8 were case-control studies.

RESULTS

After pooling and correcting for publication bias, the estimated relative risk of colorectal cancer was 1.19 [95% confidence interval (95% CI), 1.11-1.29], comparing obese (BMI > or = 30 kg/m(2)) with normal weight (BMI <25 kg/m(2)) people; and 1.45 (95% CI, 1.31-1.61), comparing those with the highest, to the lowest, level of central obesity. After correcting for publication bias, the risk of colorectal cancer was 1.41 (95% CI, 1.30-1.54) in men compared with 1.08 (95% CI, 0.98-1.18) for women (P(heterogeneity) <0.001). There was evidence of a dose-response relationship between BMI and colorectal cancer: for a 2 kg/m(2) increase in BMI, the risk of colorectal cancer increased by 7% (4-10%). For a 2-cm increase in waist circumference, the risk increased by 4% (2-5%).

CONCLUSIONS

Obesity has a direct and independent relationship with colorectal cancer, although the strength of the association with general obesity is smaller than previously reported.