Dietary fat, sugar, and fiber predict body fat content

Effect of oat supplementation interventions on cardiovascular disease risk markers: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

Oat supplementation interventions (OSIs) may have a beneficial effect on cardiovascular disease (CVD) risk. However, dietary background can modulate such effect. This systematic review assesses the effects of OSIs on CVD risk markers among adults, accounting for different dietary backgrounds or control arms.

METHODS

We included randomized clinical trials (RCTs) that assessed the effect of oat, oat beta-glucan-rich extracts or avenanthramides on CVD risk markers.

RESULTS

Seventy-four RCTs, including 4937 predominantly hypercholesterolemic, obese subjects, with mild metabolic disturbances, were included in the systematic review. Of these, 59 RCTs contributed to the meta-analyses. Subjects receiving an OSI, compared to control arms without oats, had improved levels of total cholesterol (TC) [weighted mean difference and (95% CI) - 0.42 mmol/L, (- 0.61; - 0.22)], LDL cholesterol [- 0.29 mmol/L, (- 0.37; - 0.20)], glucose [- 0.25 nmol/L, (- 0.36; - 0.14)], body mass index [- 0.13 kg/m2, (- 0.26; - 0.01)], weight [- 0.94 kg, (- 1.84: - 0.05)], and waist circumference [- 1.06 cm, (- 1.85; - 0.27)]. RCTs on inflammation and/or oxidative stress markers were scarce and with inconsistent findings. RCTs comparing an OSI to heterogeneous interventions (e.g., wheat, eggs, rice, etc.), showed lowered levels of glycated haemoglobin, diastolic blood pressure, HDL cholesterol and apolipoprotein B. The majority of included RCTs (81.1%) had some concerns for risk of bias.

CONCLUSION

Dietary OSIs resulted in lowered levels of blood lipids and improvements in anthropometric parameters among participants with predominantly mild metabolic disturbances, regardless of dietary background or control. Further high-quality trials are warranted to establish the role of OSIs on blood pressure, glucose homeostasis and inflammation markers.

Fructose and the Liver

Chronic diseases represent a major challenge in world health. Metabolic syndrome is a constellation of disturbances affecting several organs, and it has been proposed to be a liver-centered condition. Fructose overconsumption may result in insulin resistance, oxidative stress, inflammation, elevated uric acid levels, increased blood pressure, and increased triglyceride concentrations in both the blood and liver. Non-alcoholic fatty liver disease (NAFLD) is a term widely used to describe excessive fatty infiltration in the liver in the absence of alcohol, autoimmune disorders, or viral hepatitis; it is attributed to obesity, high sugar and fat consumption, and sedentarism. If untreated, NAFLD can progress to nonalcoholic steatohepatitis (NASH), characterized by inflammation and mild fibrosis in addition to fat infiltration and, eventually, advanced scar tissue deposition, cirrhosis, and finally liver cancer, which constitutes the culmination of the disease. Notably, fructose is recognized as a major mediator of NAFLD, as a significant correlation between fructose intake and the degree of inflammation and fibrosis has been found in preclinical and clinical studies. Moreover, fructose is a risk factor for liver cancer development. Interestingly, fructose induces a number of proinflammatory, fibrogenic, and oncogenic signaling pathways that explain its deleterious effects in the body, especially in the liver.

Diet quality as measured by the Diet Quality Index-International is associated with prospective changes in body fat among Canadian children

OBJECTIVE

To quantify the association of dietary quality with prospective changes in adiposity.

DESIGN

Children participating in the QUALITY (QUebec Adipose and Lifestyle InvesTigation in Youth) study underwent examination at baseline and at 2-year follow-up. Dietary quality was assessed by the Diet Quality Index-International (DQII) using three non-consecutive 24 h diet recalls at baseline. The DQII has four main categories: dietary adequacy, variety, moderation and overall balance. Fat mass index (FMI; [fat mass (kg)]/[height (m)]2), central FMI (CFMI; [trunk fat mass (kg)]/[height (m)]2), percentage body fat (%BF; [total fat mass (kg)]/[total mass (kg)]) and percentage central BF (%CBF; [trunk fat mass (kg)]/[total mass (kg)]) were assessed through dual-energy X-ray absorptiometry.

SETTING

Children were selected from schools in the greater Montreal, Sherbrooke and Quebec City metropolitan areas between 2005 and 2008, Quebec, Canada.

SUBJECTS

A total of 546 children aged 8-10 years, including 244 girls and 302 boys.

RESULTS

Regression analysis adjusting for age, sex, energy intake, physical activity and Tanner stage revealed that every 10-unit improvement in overall DQII score was associated with lower gain in CFMI (β=-0·08; 95 % CI -0·17, -0·003) and %BF (β=-0·55; 95 % CI -1·08, -0·02). Each unit improvement in dietary adequacy score was associated with lower gain in FMI (β=-0·05; 95 % CI -0·08, -0·008), CFMI (β=-0·03; 95 % CI -0·05, -0·007), %BF (β=-0·15; 95 % CI -0·28, -0·03) and %CBF (β=-0·09; 95 % CI -0·15, -0·02).

CONCLUSIONS

Promotion of dietary quality and adequacy may reduce weight gain in childhood and prevent chronic diseases later in life.

Gene-diet interactions and aging in C. elegans

Diet is the most variable aspect of life history, as most individuals have a large diversity of food choices, varying in the type and amount that they ingest. In the short-term, diet can affect metabolism and energy levels. However, in the long run, the net deficiency or excess of calories from diet can influence the progression and severity of age-related diseases. An old and yet still debated question is: how do specific dietary choices impact health- and lifespan? It is clear that genetics can play a critical role - perhaps just as important as diet choices. For example, poor diet in combination with genetic susceptibility can lead to metabolic disorders, such as obesity and type 2 diabetes. Recent work in Caenorhabditis elegans has identified the existence of diet-gene pairs, where the consequence of mutating a specific gene is only realized on specific diets. Many core metabolic pathways are conserved from worm to human. Although only a handful of these diet-gene pairs has been characterized, there are potentially hundreds, if not thousands, of such interactions, which may explain the variability in the rates of aging in humans and the incidence and severity of age-related diseases.

Comparative Study of Serum Leptin and Insulin Resistance Levels Between Korean Postmenopausal Vegetarian and Non-vegetarian Women

The present study was conducted to compare serum leptin and insulin resistance levels between Korean postmenopausal long-term semi-vegetarians and non-vegetarians. Subjects of this study belonged to either a group of postmenopausal vegetarian women (n = 54), who maintained a semi-vegetarian diet for over 20 years or a group of non-vegetarian controls. Anthropometric characteristics, serum leptin, serum glucose, serum insulin, insulin resistance (HOMA-IR; Homeostasis Model Assessment of Insulin Resistance), and nutrient intake were compared between the two groups. The vegetarians showed significantly lower body weight (p < 0.01), body mass index (p < 0.001), percentage (%) of body fat (p < 0.001), and serum levels of leptin (p < 0.05), glucose (p < 0.001), and insulin (p < 0.01), than the non-vegetarians. The HOMA-IR of the vegetarians was significantly lower than that of the non-vegetarians (p < 0.01) after adjustment for the % of body fat. A long-term vegetarian diet might be related to lower insulin resistance independent of the % of body fat in postmenopausal women.

High-Fat Diet Alters the Orosensory Sensitivity to Fatty Acids in Obesity-Resistant but not Obesity-Prone Rats

Gene-environment interactions play a role in the development of obesity but specific effects of diet on the orosensory detection of fatty acids have yet to be clarified. The objective of this study is to characterize the effect of prolonged (5-week) exposure to a high-fat (60%) diet on the behavioral sensitivity to the fatty acid linoleate following a conditioned taste aversion in obesity-prone and obesity-resistant rats. Exposure to the high-fat diet significantly enhanced the sensitivity of obesity-resistant (S5B/Pl) rats to linoleate while producing no effect on the fatty acid sensitivity for obesity-prone rats. Specifically, high-fat diet fed S5B/Pl rats showed stronger initial avoidance of linoleate and slower extinction rates than their normal diet cohorts. Our study suggests that prolonged dietary fat consumption may alter the behavioral sensitivity to fatty acids particularly in obesity-resistant animals.

Significance of coarse cereals in health and nutrition: a review

This review assesses the nutritional attributes of coarse cereals and also their utilization as food and as formulated foods. These cereals are laden with phytochemicals including phenolic acids, tannins, anthocyanins, phytosterols, avenenathramides and policosanols. They possess high antioxidant properties in vitro than staple cereals and fruits by different purported pathways. There are also some anti-nutritional factors that may be reduced by certain processing treatments. Several epidemiological studies show that these cereals are helpful in reducing several kinds of chronic diseases like cancers, cardiovascular diseases, type II diabetes and various gastrointestinal disorders. Being coarse in nature, they cannot replace our staple cereals, but can be used in different proportions with rice and wheat to formulate various nutritional products. They can be used to make porridges, biscuits, cakes, cookies, tortillas, bread, probiotic drinks, ladoo, ghatta, flakes and several fermented foods. The coarse cereals also have good potential in manufacturing bioethanol, paper, oil and biofilms.

Covariability in Diet and Physical Activity in African-American Girls

OBJECTIVE

Our goal was to examine 12-week covariability in diet and physical activity changes among 8- to 10-year-old African-American girls and if these changes predicted percent change in BMI.

RESEARCH METHODS AND PROCEDURES

Covariability among percent changes [(post - pre)/pre x 100] in nutrients, food groups, and physical activity was assessed among 127 8- to 10-year-old African-American girls. Pearson correlation and hierarchical linear regression analyses were performed.

RESULTS

Percent change in percentage kilocalories from carbohydrate was negatively correlated with percent change in both percentage kilocalories from fat (r = -0.85; p < or = 0.01) and protein (r = -0.51; p < or = 0.01). No statistically significant relationships were observed in percent changes among food group variables. Negative relationships were observed between percent changes in fruit/100% juice and percentage kilocalories from fat (r = -0.20; p < or = 0.05) and between percent changes in minutes of moderate-to-vigorous and sedentary activity (r = -0.60; p < or = 0.01). No significant associations were observed between percent change in moderate-to-vigorous physical activity and diet variables or percent change in BMI or waist circumference and percent change in diet or physical activity.

DISCUSSION

No relationships were observed between percent changes in physical activity and dietary variables. Percent change in diet and/or physical activity did not predict percent change in BMI. This may have been due to the small sample size, the small changes in diet or physical activity, the short duration of the intervention, or because data from different interventions were combined. Understanding these relationships could have significant implications for addressing the obesity epidemic.

Predictors of body mass index in female parents whose children participate in a competitive, creative, problem-solving program

BACKGROUND

Recent findings from our research indicate that children participating in a creative afterschool program exhibit overall healthier lifestyle practices compared to the average US pediatric population. This observation led us to investigate the prevalence of overweight/obesity and lifestyle practices of their parents.

OBJECTIVE

To determine the strongest predictors of weight status for female parents whose children were participating in such creative afterschool program.

DESIGN

Surveyed subjects were parents of children who competed in the 2008 and 2009 Destination ImagiNation(®) Global Finals in Knoxville, Tennessee. A total of 4,608 children participated in data collection, with parental consent. For the combined 2 years, 1,118 parents, 87% of whom were females (n=1,032) completed online questionnaires, which were based on the Behavioral Risk Factor Surveillance System and included self-reported height, weight, dietary intake, physical activity, and socioeconomic status. The majority of this population was white, and less than 5% were African American or Hispanic.

RESULTS

We report here results obtained for the female parents. Only 45.2% of these female parents were overweight/obese, compared to a national average of 64.1% reported by the National Health Nutrition Examination Surveys for 2007-2008. Furthermore, this population was significantly more physically active compared to national average. Most parents (76%) had completed a college degree and reported high incomes. Parents with the lowest income were the most obese in this population. Finally, we found a significant association between parent and child weight status.

CONCLUSIONS

These studies demonstrate that female parents of children who have healthy lifestyles were physically active, which likely accounts for the parents' lower overweight/obesity rates. In addition to physical activity, income and percentage of calories from fat were all predictors of weight status.

Effect of alginate supplementation on weight loss in obese subjects completing a 12-wk energy-restricted diet: a randomized controlled trial

BACKGROUND

Acute studies with alginate-based preloads suggested that these strong gelling fibers may induce increased feelings of satiety and reduce energy intakes. However, the long-term efficacy and safety of alginate supplementation on body weight regulation are lacking.

OBJECTIVE

The primary aim of the study was to investigate the effects in subjects of alginate supplementation in conjunction with energy restriction (-300 kcal/d) on loss of body weight and fat and, second, on metabolic risk markers in comparison with in a placebo group.

DESIGN

In a parallel, double-blind, placebo-controlled study, we randomly assigned 96 obese subjects to either an energy-restricted diet plus a placebo preload supplement or an energy-restricted diet plus an alginate-based preload supplement (15 g fiber). The preload was administered as a beverage 3 times/d before main meals for a period of 12 wk.

RESULTS

No differences in loss of body weight and fat between groups were shown in the intension-to-treat (ITT) analysis (P > 0.1). However, in the completer analysis (n = 80), we showed a greater weight loss with alginate (6.78 ± 3.67 kg) than with the placebo (5.04 ± 3.40 kg) (P = 0.03), which was mainly attributed to a reduction in the percentage of body fat (P = 0.03). In the ITT analysis, a larger decrease in systolic and diastolic blood pressure was shown in the placebo group than in the alginate group (P < 0.05). Plasma concentrations of glucose, insulin, C-reactive protein, and ghrelin, HOMA-IR, and lipid metabolism did not differ between treatment groups in the ITT analysis (P > 0.1).

CONCLUSION

These results suggest that alginate supplementation as an adjunct to energy restriction may improve weight loss in obese subjects who complete a 12-wk dietary intervention.

Long-term vegetarians have low oxidative stress, body fat, and cholesterol levels

Excessive oxidative stress and abnormal blood lipids may cause chronic diseases. This risk can be reduced by consuming an antioxidant- and fiber-rich vegetarian diet. We compared biomarkers of oxidative stress, antioxidant capacity, and lipid profiles of sex- and age-matched long-term vegetarians and omnivores in Korea. Forty-five vegetarians (23 men and 22 women; mean age, 49.5 ± 5.3 years), who had maintained a vegetarian diet for a minimum of 15 years, and 30 omnivores (15 men and 15 women; mean age, 48.9 ± 3.6 years) participated in this study. Their 1-day, 24-h recall, and 2-day dietary records were analyzed. Oxidative stress was measured by the levels of diacron reactive oxygen metabolites (d-ROM). Antioxidant status was determined by the biological antioxidant potential (BAP) and levels of endogenous antioxidant enzymes such as superoxide dismutase, catalase, and glutathione peroxidase. We observed that vegetarians had a significantly lower body fat percentage (21.6 ± 6.4%) than that of omnivores (25.4 ± 4.6%; P < 0.004). d-ROM levels were significantly lower in vegetarians than those in omnivores (331.82 ± 77.96 and 375.80 ± 67.26 Carratelli units; P < 0.011). Additionally, total cholesterol levels in the vegetarians and omnivores were 173.73 ± 31.42 mg/dL and 193.17 ± 37.89 mg/dL, respectively (P < 0.018). Low-density lipoprotein cholesterol was 101.36 ± 23.57 mg/dL and 120.60 ± 34.62 mg/dL (P < 0.005) in the vegetarians and omnivores, respectively, indicating that vegetarians had significantly lower lipid levels. Thus, oxidative stress, body fat, and cholesterol levels were lower in long-term vegetarians than those in omnivores.

Differences in food intake among obese and nonobese women and men with type 2 diabetes

OBJECTIVE

Weight reduction is a key goal for the prevention of vascular complications in obese individuals with type 2 diabetes, but a nutritionally balanced intake is also important in this regard. We compared dietary intakes and vitamin supplement use between obese and nonobese women and men with type 2 diabetes to identify gaps in adherence to nutritional management guidelines.

METHODS

We analyzed data from a longitudinal study of adults with type 2 diabetes, wherein participants were assessed once per season over 1 year. Dietary data were collected using a validated semiquantitative, self-administered food-frequency questionnaire. Given the absence of seasonal variations in anthropometric variables and dietary intake, data from multiple visits were averaged for each individual. Associations of both intake of fruit and vegetables and nutrients related to cardiovascular disease risk were compared between obese (body mass index ≥ 30 kg/m²) and nonobese individuals through multivariable linear regression with adjustments for age, education, and energy intake.

RESULTS

Among the 200 participants (93 women and 107 men), 53% of women and 43% of men were obese. Compared with nonobese women, obese women consumed more saturated fat (mean difference, 1.2% of total energy intake; 95% confidence interval [CI], 3% to 2.2%) and sodium (mean difference, 0.3 g; 95% CI, 0.04 to 0.5 g), and they had a lower intake of fiber (mean difference, -2.7 g; 95% CI, -4.4 to -0.9 g) and magnesium (mean difference, -33.6 mg; 95% CI, -55.2 to -12.0 g). No differences in dietary intake were observed between obese and nonobese men, but the intakes of men overall were similar to those of obese women. Compared with nonobese participants, fewer obese individuals used vitamin/mineral supplements (women: 37% vs 48%, men: 26% vs 38%).

CONCLUSIONS

Obese women and both obese and nonobese men appeared to have poorer dietary quality compared with nonobese women. Our findings support the need to emphasize dietary composition in addition to weight control in diabetes.

Whole grain and fiber consumption are associated with lower body weight measures in US adults: National Health and Nutrition Examination Survey 1999-2004

This study examined the association of whole grain consumption with body weight measures and prevalence of overweight/obesity in a recent, nationally representative sample of adults. A secondary analysis of 1999-2004 National Health and Nutrition Examination Survey (NHANES) data was conducted using adults 19 to 50 years of age (y) (n = 7,039) and 51+ y (n = 6,237). Participants were categorized by whole grain consumption: ≥ 0 to <0.6, ≥ 0.6 to <1.5, ≥ 1.5 to <3.0, and ≥ 3.0 servings/day. Main outcome measures included body mass index (BMI), waist circumference (WC), and prevalence of overweight/obesity. Sample weights were applied and the number and percentages of adults in whole grain consumption groups were determined. Least-square means and standard errors were calculated for body weight measures. Two regression models were developed and compared. Model 1 covariates included age, gender, ethnicity, and total energy intake; Model 2 was extended to include cereal fiber. Trend analysis was conducted to test for differences between least-square means. Significance was set at P ≤ .05. Adults 19-50 and 51+ y consumed a mean of 0.63 and 0.77 servings of whole grains/day, respectively. A significant trend was observed in both age groups for increased consumption of whole grains with lower BMI, WC, and percentage overweight/obese (Model 1); however, a significant trend was not observed when cereal fiber was added as a covariate (Model 2). Results confirm overall whole grain intake well below recommendations, and adults who consumed the most servings of whole grains had lower body weight measures. Results also suggest that fiber in whole grain foods may mediate associations with weight measures in adults. Intake of whole grain foods should be encouraged by health professionals.

Chlamydophila pneumoniae antibodies may be independently associated with increased BMI and percentage of body fat among women

OBJECTIVE

To examine the potential association between Chlamydophila pneumoniae infection and obesity indicators after controlling for nutrient and energy intake, as well as age, smoking status, physical activity and educational level.

SUBJECTS

A total of 118 healthy adult females randomly recruited from the local community of Bydgoszcz, aged 20-80 years.

METHODS

Serum was tested for specific IgG antibodies against C. pneumoniae using qualitative enzyme linked immunosorbent assay. Usual dietary intake was assessed by a 7-day food record. Information regarding smoking, physical activity and educational level was collected using the questionnaire. Body mass index (BMI) and percentage of total body fat (%FM) were calculated respectively, as weight (kilograms) divided by height (meters) squared and with the equations of Durnin and Womersley.

RESULTS

The prevalence of C. pneumoniae infection was significantly higher among overweight/obese subjects (77.1 vs 60.0%; P=0.047) in comparison with normal-weight individuals. Using multivariate regression analysis, a significant positive association of BMI (β=0.194; P=0.036) and %FM (β=0.176; P=0.049) with C. pneumoniae IgG antibody positivity was found after adjustment for age, total energy intake, percentage of energy from fat, carbohydrate and protein, physical activity, educational level and smoking habits. Moreover, the multivariable adjusted odds ratio of being overweight/obese for the seropositive group compared with seronegative individuals was 1.70 (95% confidence interval: 1.02-2.89; P=0.037).

CONCLUSION

The results indicated that C. pneumoniae infection may be associated with a risk of becoming overweight/developing obesity independently of dietary and lifestyle factors.

Hypoxia-inducible factor-1alpha regulates beta cell function in mouse and human islets

Hypoxia-inducible factor-1alpha (HIF-1alpha) is a transcription factor that regulates cellular stress responses. While the levels of HIF-1alpha protein are tightly regulated, recent studies suggest that it can be active under normoxic conditions. We hypothesized that HIF-1alpha is required for normal beta cell function and reserve and that dysregulation may contribute to the pathogenesis of type 2 diabetes (T2D). Here we show that HIF-1alpha protein is present at low levels in mouse and human normoxic beta cells and islets. Decreased levels of HIF-1alpha impaired glucose-stimulated ATP generation and beta cell function. C57BL/6 mice with beta cell-specific Hif1a disruption (referred to herein as beta-Hif1a-null mice) exhibited glucose intolerance, beta cell dysfunction, and developed severe glucose intolerance on a high-fat diet. Increasing HIF-1alpha levels by inhibiting its degradation through iron chelation markedly improved insulin secretion and glucose tolerance in control mice fed a high-fat diet but not in beta-Hif1a-null mice. Increasing HIF-1alpha levels markedly increased expression of ARNT and other genes in human T2D islets and improved their function. Further analysis indicated that HIF-1alpha was bound to the Arnt promoter in a mouse beta cell line, suggesting direct regulation. Taken together, these findings suggest an important role for HIF-1alpha in beta cell reserve and regulation of ARNT expression and demonstrate that HIF-1alpha is a potential therapeutic target for the beta cell dysfunction of T2D.

Association of postprandial and fasting triglycerides with traits of the metabolic syndrome in the Metabolic Intervention Cohort Kiel

OBJECTIVE

Postprandial (pp) lipid metabolism is associated with insulin resistance and type 2 diabetes. In young men, pp triglycerides (TGs) are more strongly associated with traits of metabolic syndrome (MS) than fasting TGs. We established a cohort of middle-aged men selected for traits of MS and pp lipid metabolism to determine if fasting TGs or pp TGs are more closely related to MS.

RESEARCH DESIGN AND METHODS

A total of 1558 men were characterized for MS. A total of 755 men underwent an oral metabolic tolerance test consisting of a standardized high-fat meal and an oral glucose tolerance test. Blood samples were drawn in the fasting state and hourly until 9 h to determine pp TGs and free fatty acids. Glucose and insulin were analyzed until 5 h pp.

RESULTS

In the overall cohort, 329 subjects (21.1%) had a complete MS based on the Adult Treatment Panel III criteria, and 650 subjects (41.7%) had a complete MS based on the International Diabetes Federation criteria. The association of pp TGs with MS parameters was not stronger than the association of fasting TGs with them. Pp TGs were independently associated with beta-cell function.

CONCLUSIONS

Pp TGs did not show a higher correlation with MS traits than fasting TGs. This finding is probably due to the high incidence of overweight subjects in this middle-aged cohort.

Oat β-glucan supplementation does not enhance the effectiveness of an energy-restricted diet in overweight women

Epidemiological evidence shows an inverse relationship between dietary fibre intake and body weight gain. Oat β-glucan, a soluble fibre alters appetite hormones and subjective satiety in acute meal test studies, but its effects have not been demonstrated with chronic consumption. The present study aimed to test the effects in women of two different doses of oat β-glucan on weight loss and hormones associated with appetite regulation. In a 3-month parallel trial, sixty-six overweight females were randomised into one of three 2 MJ energy-deficit diets: a control and two interventions including 5–6 g or 8–9 g β-glucan. Anthropometric and metabolic variables (blood glucose level, insulin, total cholesterol (TC), LDL, HDL, TAG and leptin), together with markers of appetite regulation (cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), ghrelin, peptide YY (PYY) and PYY3-36) were measured at baseline and at 3 months. After 3 months, all groups lost weight (P < 0·001) and showed a reduced waist circumference (P < 0·001). The study sample also showed reductions in TC, LDL, HDL, leptin, PYY, GLP-1 values (all P < 0·001) and an increase in CCK levels (P < 0·001). No significant differences were noted between the groups for all outcome values except PYY levels (P = 0·018). In broad terms, the addition of oat β-glucan did not enhance the effect of energy restriction on weight loss in mildly overweight women, although wide variations in observed results suggests that individual responsiveness may be an issue.

Food types in the diet and the nutrient intake of obese and non-obese children

BACKGROUND

Childhood obesity has reached epidemic proportions world-wide.

OBJECTIVE

To compare the types of food in the diet and the nutrient intake of obese children with those of non-obese children.

METHODS

A total of 95 obese and 592 non-obese children aged between 6 and 10 years participated in the study. A body mass index (BMI) value exceeding the 95th percentile for age and gender was taken as the criterion for obesity. Three-day food consumption was recorded and evaluated according to standard international recommendations.

RESULTS

Macronutrient intake was adequate in both obese and non-obese children. Energy intake of the obese children was significantly higher than that of the non-obese children. Micronutrient intake except fiber of both groups, calcium intake of obese children and vitamin A intake of non-obese children were higher than recommended amounts. The obese children consumed excessive fat and sugar, but less fruit and vegetables as compared to the non-obese children, and less than the recommendations of the food guide pyramid as adopted by the US Department of Food and Agriculture and the Department of Health and Human Services.

CONCLUSION

The implementation of educational programs on nutrition may be important for promoting knowledge about healthy eating among obese children.

Novel calcium-gelled, alginate-pectin beverage reduced energy intake in nondieting overweight and obese women: interactions with dietary restraint status

BACKGROUND

Foods containing strong-gelling fibers may provide a safe and efficacious strategy for reducing food intake by stimulating endogenous satiety signaling.

OBJECTIVE

A novel, 2-part beverage, consisting of alginate-pectin and calcium components, that forms a stable, fibrous gel in the stomach was tested to determine its effects on subjective satiety and food intake in overweight and obese women.

DESIGN

The investigation was a within-subjects, double-blind, placebo-controlled study. Subjects (n = 29) ingested a 2-part beverage twice per day (once before breakfast and once midafternoon) for 7 d. Three alginate-pectin formulations were tested: 1.0 g, 2.8 g, and control (no fiber). Subjective satiety and ad libitum food intake were measured on days 1 and 7 of each 1-wk treatment period with a 1-wk washout between testings.

RESULTS

A significant reduction in food intake was observed at dinner for both formulations compared with the control formulation. The effects of the gel beverage differed as a function of rigid dietary restraint status. Women in the lower 50th percentile of rigid restraint consumed 12% less energy during the day and 22% less for the evening snack in the 2.8-g condition compared with the control condition. No effect was found for women in the upper 50th percentile of rigid restraint.

CONCLUSIONS

Consumption of a postingestion, calcium-gelled fiber beverage twice daily reduced energy intake in overweight and obese women with low rigid restraint scores. Use of foods designed to enhance satiety may be an effective adjunctive therapy for weight loss; however, more research is needed to determine how dietary restraint alters this response.

The benefits of early intervention in obese diabetic patients with FBCx: a new dietary fibre

BACKGROUND

Obesity and diabetes have become epidemic in the US. Dietary fibres have been reported to reduce the absorption of dietary fat, prevent weight gain, and reduce blood lipid levels. In the current double-blind study, obese patients with type 2 diabetes were recruited for a 3-month study to examine the health effects of a new dietary fibre, FBCx.

METHODS

Sixty-six participants were recruited and were randomized into FBCx or placebo groups. They were instructed to take two 1-g tablets per fat-containing meal and not to change their eating patterns or daily routine. Three-day dietary records and fasting blood samples were collected prior to enrollment in the study and at the end of months 1, 2 and 3.

RESULTS

Dietary records showed that some participants changed their eating patterns; therefore body weight data were adjusted according to energy intake. As a group, in the 30 days leading into the study, all participants experienced an average weight gain of 1.0 +/- 0.4 kg, while those in the placebo group continued to gain weight during the study, those in the FBCx group maintained their weight. Those in the FBCx group required more energy to maintain their body weight while those in the placebo group required less (p < 0.05). Participants with hypertriglyceridemia showed a reduction (-0.48 +/- 0.24 mmol/L, - 8.2%) in total cholesterol with FBCx, while those with placebo had an increase (0.24 +/- 0.21 mmol/L, 5.2%, p < 0.05). Adiponectin was increased in the FBCx but reduced in the placebo group (p < 0.05).

CONCLUSIONS

FBCx has thus shown promising benefits in weight maintenance, a reduction of blood lipids and an increase in adiponectin levels. It can be easily incorporated into a diabetic management regimen.

Fiber intake, constipation, and overweight among adolescents living in Sao Paulo City

OBJECTIVE

This study evaluated the dietary fiber intake of adolescents in the metropolitan area of Sao Paulo city and any association between low dietary fiber intake with constipation and overweight.

METHODS

In total, 716 adolescents were included within the study, of whom 314 attended private school and 402 attended public school. Evaluation of fiber intake was based on a 24-h daily intake record and a frequency questionnaire. Data concerning bowel movements and height and weight measurements were also taken.

RESULTS

Fiber consumption, below that recommended ("age + 5"), was found in 61.8% and 41.4% (P = 0.000) of girls attending private and public schools, respectively, and in 44.1% and 25.6% of boys (P = 0.001). Adolescents who did not eat beans on more than 4 d/wk presented a higher risk of fiber intake below that recommended (age + 5; P < 0.05), with odds ratios ranging from 10.4 to 14.2 according gender and private or public schooling. Dietary fiber intake below that recommended was associated with a greater risk (P < 0.05) toward overweight in students attending public schooling (odds ratios 2.84 and 2.95 for males and females, respectively). Low dietary fiber intake was not associated with constipation.

CONCLUSION

Intake of beans more than four times per week is associated with the appropriate level of fiber intake. Dietary fiber intake below the recommendation was not associated with constipation but was associated with being overweight among those students attending public schooling.

Reference body composition in adult rhesus monkeys: glucoregulatory and anthropometric indices

Rhesus monkeys have been used as models to study obesity and disease. The aim of this study was to define body mass indices for underweight and obesity in rhesus monkeys. Longitudinal data collected over 8-14 years from 40 male and 26 female rhesus monkeys were analyzed. Body weight, insulin sensitivity index, and disposition index were regressed against percent body fat (%BF). A minimal %BF beyond which further loss of body weight resulted in loss of lean mass was determined to be 11.5% in older males, 8% in adult females, and 9% in younger adult males. Insulin sensitivity index and disposition index reached minimum values at 23% fat in older males, 18% in adult females, and 21% in younger adult males, indicating obesity. The estimated reference range for %BF was 9%-23% in male and 8%-18% in female monkeys, corresponding to body mass indices of 32-44 kg/m(2) for male and 27-35 kg/m(2) for female monkeys.

Detection of free fatty acids following a conditioned taste aversion in rats

A gustatory transduction mechanism for free fatty acids (FFAs) has been described in isolated rat taste receptor cells; however, the ability of behaving rats to detect FFAs has not been characterized. Through conditioned taste aversion (CTA) methodology, this study defines the ability of rats to detect and avoid the two principal FFA components of corn oil, linoleic and oleic acid. Following taste aversion conditioning, rats avoided both linoleic and oleic acid at greater than or equal to 66 muM and failed to avoid either 44 muM linoleic or oleic acid. Rats demonstrated generalized avoidances between 88 muM linoleic and oleic acid irrespective of presenting the FFAs as either unesterified acids dissolved in 5 mM ethanol or aqueous sodium salts, sodium linoleate and sodium oleate. Following a CTA to linoleic acid, rats did not show generalized avoidance of NaCl or ethanol, two potentially concomitant tastants in the oral cavity. A CTA to linoleic or oleic acid did produce a generalized avoidance to the other FFA. These results support the ability of rats to detect linoleic and oleic acid (>44 muM) and suggest that the two FFAs share common orosensory properties. Furthermore, it is unlikely that the detection of the FFAs is due to an enhancement of other concomitant tastants such as saliva or the delivery solution.

Dietary fiber and body weight

OBJECTIVE

This review provides an update of recent studies of dietary fiber and weight and includes a discussion of potential mechanisms of how dietary fiber can aid weight loss and weight maintenance.

METHODS

Human studies published on dietary fiber and body weight were reviewed and summarized. Dietary fiber content of popular low-carbohydrate diets were calculated and are presented.

RESULTS

Epidemiologic support that dietary fiber intake prevents obesity is strong. Fiber intake is inversely associated with body weight and body fat. In addition, fiber intake is inversely associated with body mass index at all levels of fat intake after adjusting for confounding factors. Results from intervention studies are more mixed, although the addition of dietary fiber generally decreases food intake and, hence, body weight. Many mechanisms have been suggested for how dietary fiber aids in weight management, including promoting satiation, decreasing absorption of macronutrients, and altering secretion of gut hormones.

CONCLUSION

The average fiber intake of adults in the United States is less than half recommended levels and is lower still among those who follow currently popular low-carbohydrate diets, such as Atkins and South Beach. Increasing consumption of dietary fiber with fruits, vegetables, whole grains, and legumes across the life cycle is a critical step in stemming the epidemic of obesity found in developed countries. The addition of functional fiber to weight-loss diets should also be considered as a tool to improve success.

Dietary Fiber and Fat Are Associated with Excess Weight in Young and Middle-Aged US Adults

OBJECTIVE

To examine relative associations of dietary composition variables with body mass index (BMI; calculated as kg/m2) among young and middle-aged US adults. We hypothesized that in subjects with physiologically plausible reported energy intakes, fiber intake would be inversely associated with BMI, independent of other dietary composition and sociodemographic variables.

SUBJECTS AND DESIGN

Data from adults age 20 to 59 years in the Continuing Survey of Food Intakes by Individuals (CSFII) 1994-1996 were used. Exclusions were pregnancy or lactation, food insecurity, missing weight or height data, or having only one dietary recall. Based on our previously published methods, a physiologically plausible reported energy intake was calculated as being within +/-22% of predicted energy requirements for the mean of two 24-hour recalls.

RESULTS

Reporting plausibility ([reported energy intake/predicted energy requirements]x100) averaged 83% in the total sample (N=4,539) and increased to 96% in the plausible sample (n=1,932). Only approximately 5% of the plausible sample consumed the Adequate Intake for fiber. In plausibly reporting women, fiber, its interaction with percentage energy from fat, and energy density were independently associated with BMI. Only percentage energy from fat was associated with BMI in men reporting plausibly. Compared with the total sample, stronger relationships between diet and BMI were observed among the plausible reporters. In women, a low-fiber (< 1.5 g/MJ), high-fat (> or = 35% energy) diet was associated with the greatest increase in risk of overweight or obesity compared with a high-fiber, low-fat diet.

CONCLUSIONS

Weight control advice for US women should place greater emphasis on consumption of fiber.

Regulatory effect of dosiinpartner on high-fat diet-induced obesity in C57BL/6J mice

Dosiinpartner (DSP) is a newly developed dietary functional food to help control weight. The aim of this study was to evaluate whether DSP combined with a high-fat (HF) diet could influence body weight, fat accumulation, and plasma glucose levels. Mice were fed for 8 weeks with normal diet, HF diet, and HF+10% or 20% DSP diet. Body weight was recorded at 1 week, and plasma levels of total cholesterol, low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and glucose were analyzed at the end of the study. Weight increases in the 10% or 20% DSP group were significantly less than in the HF diet group (p<0.05). Plasma total cholesterol and LDL cholesterol levels decreased by 48.3% and 26.8% in the 10% DSP group and by 42.9% and 34.9% in the 20% DSP group, respectively. However, the HDL cholesterol level was unchanged. Glucose levels also decreased by 80.6% in the 10% DSP group but was almost the same in the HF and 20% DSP groups. Our findings indicate that DSP may be beneficial in the regulation of high-fat diet-induced overweight and other complications such as circulatory disorders and diabetes mellitus.

[Knowledge and gaps on the role of nutrition and physical activity on the onset of childhood obesity]

Childhood and adolescent obesity has increased at alarming rates over the last few years, due to the concurrence of a variety of genetic and environmental factors. The aim of this study was to conduct a review of published studies in the past ten years evaluating the development of childhood obesity in relation to energy and macronutrients intake, their distribution throughout the day and physical activity patterns. 31 articles dealing with this subject were selected. Results obtained appear to indicate that reducing dietary fat and increasing dietary carbohydrate intakes along with consuming an adequate breakfast and carrying out leisure time physical activity on a regular basis act as determining factors to prevent childhood and adolescent obesity, even though the strength of the evidence from these studies is low. It should be a priority to conduct follow-up studies with comparable methodologies in Mediterranean countries, in order to establish parameters for the prevention and control of childhood and adolescent obesity.

Regulatory Effect of Sense Line Diet on Cholesterol and Body Weight in Mice Fed a High-Fat Diet

BACKGROUND/AIMS

Sense line diet (SLD) is a newly developed dietary functional food that is composed of a lot of herbs. The function of SLD is to help control weight. Although it is reported that each herb has effects on lipid metabolism and obesity, these effects are not the same as SLD. The aim of this study was therefore to investigate whether SLD combined with high fat (HF) diet can influence body weight and fat accumulation.

METHODS

An experiment was conducted with 40 C57BL/6J mice with an initial body weight of about 16 g. Body weight was recorded every week, plasma levels of triglyceride, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol were analyzed at the end of the study.

RESULTS

Weight increases in the 10 or 20% SLD group were significantly less than in the HF diet group (p < 0.05). Plasma triglyceride and LDL cholesterol levels were decreased by 52.1 and 34.2% in the 10% SLD group and 15.4 and 15.4% in the 20% SLD group, respectively, compared to the high-fat diet group. HDL cholesterol level was increased by 7.8% in the 10% SLD and by 54.9% in the 20% SLD group.

CONCLUSIONS

Our findings indicate that SLD may be beneficial in the regulation of high-fat-diet-induced blood circulatory disorders as well as overweight.

MooPoong (Gye Young Jeong) Increases HDL‐Cholesterol but Decreases LDL Cholesterol and Body‐Weight

MooPoong (MP, Gye Young Jeong), a Korean traditional wine, has been used as a prevention and treatment agent of blood circulatory trouble. To evaluate such an effect of MP, we analyzed whether the plasma levels of low-density lipoprotein (LDL) cholesterol, high-density lipoprotein (HDL) cholesterol, and body weight change after rats were fed on high fat diet with MP for 8 weeks. Plasma LDL cholesterol level decreased by 5.6% in 0.128% MP treated group and by 11.1% in 0.640% MP treated group. However, HDL cholesterol was increased by 6.7% in 0.128% MP diet group and 33.3% in 0.640% MP diet group. In addition, there was a significant weight loss in the MP treated group compared with the high-fat diet group (P < 0.05). Our findings indicate that MP may contain compounds with actions which can treat blood circulatory trouble as well as overweight.

Changes in whole-grain, bran, and cereal fiber consumption in relation to 8-y weight gain among men

BACKGROUND

Epidemiologic studies that directly examine changes in whole-grain consumption in relation to weight gain are sparse, and characterization of this association has been obscured by methodologic inconsistencies in the assessment of whole grains.

OBJECTIVE

We aimed to ascertain the associations between changes in new quantitative estimates of whole-grain intake and 8-y weight gain among US men.

DESIGN

The study was conducted in a prospective cohort of 27 082 men aged 40-75 y at baseline in 1986. Data on lifestyle factors were obtained periodically by using self-reported questionnaires, and participants measured and reported their body weight in 1986 and 1994.

RESULTS

In multivariate analyses, an increase in whole-grain intake was inversely associated with long-term weight gain (P for trend < 0.0001). A dose-response relation was observed, and for every 40-g/d increment in whole-grain intake from all foods, weight gain was reduced by 0.49 kg. Bran that was added to the diet or obtained from fortified-grain foods further reduced the risk of weight gain (P for trend = 0.01), and, for every 20 g/d increase in intake, weight gain was reduced by 0.36 kg. Changes in cereal and fruit fiber were inversely related to weight gain. No associations were observed between changes in refined-grain or added germ consumption and body weight.

CONCLUSIONS

The increased consumption of whole grains was inversely related to weight gain, and the associations persisted after changes in added bran or fiber intakes were accounted for. This suggests that additional components in whole grains may contribute to favorable metabolic alterations that may reduce long-term weight gain.

Ready-to-eat cereal consumption: its relationship with BMI and nutrient intake of children aged 4 to 12 years

OBJECTIVE

To examine the relationship between ready-to-eat cereal consumption habits and body mass index of a sample of children aged 4 to 12 years.

DESIGN

Fourteen-day self-reported food diary records were obtained from a sample of 2,000 American households from February 1998 through February 1999. Height and weight of the family members were also self-reported.

SUBJECTS/SETTING

The sample population of 603 children, aged 4 to 12 years, was broken into tertiles based on cereal consumption over the 14 days: (three or fewer, four to seven, or eight or more servings).

STATISTICAL ANALYSIS

Logistic regression and analysis of variance were used to determine associations between frequency of ready-to-eat cereal consumption and body mass index or nutrient intakes.

RESULTS

More than 90% of children aged 4 to 12 years consumed ready-to-eat cereal at least once in the two-week collection period. Within tertiles of consumption, children in the upper tertile had lower mean body mass indexes than those in the lowest tertile consistently across all age groups (P<.01). Additionally, the proportion of children aged 4 to 12 years who were at risk for overweight/overweight was significantly lower in the upper tertile of cereal consumption (P<.05). Children in the upper tertile also had lower fat intakes and higher intakes of many micronutrients.

APPLICATIONS

The consumption of ready-to-eat cereals at breakfast should be encouraged as a component of an eating pattern that promotes the maintenance of healthful body weights and nutrient intakes in children.

Diet, Obesity and Education in Three Age Groups of Saskatchewan Women

Research on relationships between socioeconomic status and Canadians’ diet is limited. The current study investigated differences by education in dietary variables shown to be related to obesity; it included three age groups of Saskatchewan women who participated in the 1992 to 1993 Heart Health Intervention Evaluation baseline study. Multistage sampling was used to select randomly from the Saskatchewan Health Insurance Registration File. The overall response rate was 42.6%; a sample representative of the general Saskatchewan population was obtained. Three-day estimated food records and demographic information from 396 women aged 18 to 74 years were subdivided into three age categories: 18 to 34 years, 35 to 54 years, and 55 to 74 years. For the 18- to 34-year group, obesity was significantly more prevalent with lower education; trends were similar for the older age groups. Under-reporting of energy intake (indicated by an energy intake:basal metabolic rate ratio of <1.1) was related to obesity but not to education. The greatest differences in diet between educational groups were observed in the 18- to 34-year group; fewer differences existed in the 35- to 54-year group, and none in the 55- to 74-year group. Health promotion efforts need to be targeted appropriately, and based on differences in dietary intakes by socioeconomic group. Research should help promote an understanding of the reasons for differences in diet by socioeconomic status.

Herbal preparations for obesity: are they useful?

The opportunities for additional research in this area are plentiful. Unfortunately, there has been relatively limited funding for research on herbal supplements compared with the amount of funding that is available for research on pharmaceuticals. Botanical dietary supplements often contain complex mixtures of phytochemicals that have additive or synergistic interactions. For example, the tea catechins include a group of related compounds with effects that are demonstrable beyond those that are seen with epigallocatechin gallate, the most potent catechin. The metabolism of families of related compounds may be different than the metabolism of purified crystallized compounds. In some cases, herbal medicines may simply be less purified forms of single active ingredients, but in other cases they represent unique formulations of multiple, related compounds that may have superior safety and efficacy compared with single ingredients. Obesity is a global epidemic, and traditional herbal medicines may have more acceptance than prescription drugs in many cultures with emerging epidemics of obesity. Several ethnobotanical studies found herbal treatments for diabetes, and similar surveys, termed bioprospecting, for obesity treatments may be productive. Beyond increasing thermogenesis, there are other biological rationales for the actions of several different alternative medical and herbal approaches to weight loss. For example, several supplements and herbs claim to result in nutrient partitioning so that ingested calories will be directed to muscle, rather than fat. These include an herb (Garcinia cambogia), and a lipid which is the product of bacterial metabolism (conjugated linoleic acid). Moreover, a series of approaches attempt to physically affect gastric satiety by filling the stomach. Fiber swells after ingestion and has was found to result in increased satiety. A binding resin (Chitosan) has the ability to precipitate fat in the laboratory and is touted for its ability to bind fat in the intestines so that it is not absorbed. In double-blind studies, however, this approach was found to be ineffective. There are two key attractions of alternative treatments to obese patients. First, they are viewed as being natural and are assumed by patients to be safer than prescription drugs. Second, there is no perceived need for professional assistance with these approaches. For obese individuals who cannot afford to see a physician, these approaches often represent a more accessible solution. Finally, for many others, these approaches represent alternatives to failed attempts at weight loss with the use of more conventional approaches. These consumers are often discouraged by previous failures, and are likely to combine approaches or use these supplements at doses higher than are recommended. It is vital that the primary care physician is aware of the herbal preparations that are being used by patients so that any potential interaction with prescription drugs or underlying medical conditions can be anticipated. Unfortunately, there have been several instances where unscrupulous profiteers have plundered the resources of the obese public. Although Americans spend $30 billion per year on weight loss aids, our regulatory and monitoring capability as a society are woefully inadequate. Without adequate resources, the FDA resorted to "guilt by association" adverse events reporting, which often results in the loss of potentially helpful therapies without adequate investigation of the real causes of the adverse events that are reported. Scientific investigations of herbal and alternative therapies represent a potentially important source for new discoveries in obesity treatment and prevention. Cooperative interactions in research between the Office of Dietary Supplements, the National Center for Complementary and Alternative Medicine, and the FDA could lead to major advances in research on the efficacy and safety of the most promising of these alternative approaches.

Diet and body mass index in 38000 EPIC-Oxford meat-eaters, fish-eaters, vegetarians and vegans

OBJECTIVE

To compare body mass index (BMI) in four diet groups (meat-eaters, fish-eaters, vegetarians and vegans) in the Oxford cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC-Oxford) and to investigate lifestyle and dietary factors associated with any observed differences.

DESIGN

Cross-sectional analysis of self-reported dietary, anthropometric and lifestyle data.

PARTICIPANTS

A total of 37875 healthy men and women aged 20-97 y participating in EPIC-Oxford.

RESULTS

Age-adjusted mean BMI was significantly different between the four diet groups, being highest in the meat-eaters (24.41 kg/m(2) in men, 23.52 kg/m(2) in women) and lowest in the vegans (22.49 kg/m(2) in men, 21.98 kg/m(2) in women). Fish-eaters and vegetarians had similar, intermediate mean BMI. Differences in lifestyle factors including smoking, physical activity and education level accounted for less than 5% of the difference in mean age-adjusted BMI between meat-eaters and vegans, whereas differences in macronutrient intake accounted for about half of the difference. High protein (as percent energy) and low fibre intakes were the dietary factors most strongly and consistently associated with increasing BMI both between and within the diet groups.

CONCLUSIONS

Fish-eaters, vegetarians and especially vegans had lower BMI than meat-eaters. Differences in macronutrient intakes accounted for about half the difference in mean BMI between vegans and meat-eaters. High protein and low fibre intakes were the factors most strongly associated with increasing BMI.

Whole grain consumption and weight gain: a review of the epidemiological evidence, potential mechanisms and opportunities for future research

The epidemiological data that directly examine whole grain v. refined grain intake in relation to weight gain are sparse. However, recently reported studies offer insight into the potential role that whole grains may play in body-weight regulation due to the effects that the components of whole grains have on hormonal factors, satiety and satiation. In both clinical trials and observational studies the intake of whole-grain foods was inversely associated with plasma biomarkers of obesity, including insulin, C-peptide and leptin concentrations. Whole-grain foods tend to have low glycaemic index values, resulting in lower postprandial glucose responses and insulin demand. High insulin levels may promote obesity by altering adipose tissue physiology and by enhancing appetite. The fibre content of whole grains may also affect the secretion of gut hormones, independent of glycaemic response, that may act as satiety factors. Future studies may examine whether whole grain intake is directly related to body weight, and whether the associations are primarily driven by components of the grain, including dietary fibre, bran or germ.

Interaction of body mass index and attempt to lose weight in a national sample of US adults: association with reported food and nutrient intake, and biomarkers

OBJECTIVE

This study examined the interaction between body mass index (BMI) and attempting to lose weight for reporting of: (1) macro- and micronutrient intake; (2) intake of low-nutrient-density foods; and (3) serum biomarkers of dietary exposure and cardiovascular disease risk.

METHODS

Dietary, anthropometric and biochemical data were from the third National Health and Nutrition Examination Survey (1988-1994), n=13 095. Multiple regression methods were used to examine the independent associations of BMI, trying to lose weight, or the interaction of BMI-trying to lose weight with reported intakes of energy, nutrients, percentage energy from low-nutrient-density foods (sweeteners, baked and dairy desserts, visible fats and salty snacks), and serum concentrations of vitamins, carotenoids and lipids.

RESULTS

BMI was an independent positive predictor (P<0.05) of percentage of energy from fat, saturated fat, but a negative predictor of the ratio of reported energy intake to estimated expenditure for basal needs (EI/BEE), percentage of energy from carbohydrate and alcohol (men only), and serum concentrations of folate, vitamin C, vitamin E and most carotenoids in both men and women. Trying to lose weight was a negative predictor (P<0.05) of EI/BEE, intake of energy, and energy density, but not micronutrient intake. Higher mean serum ascorbate, vitamin E, lutein/zeaxanthin, and other carotenoids (men only) concentrations were associated with trying to lose weight (P<0.05) in both men and women. Few adverse BMI-trying to lose weight interaction effects were noted.

CONCLUSIONS

There was little evidence of increased nutritional risk in those reportedly trying to lose weight irrespective of weight status.

Effect of whole grains on insulin sensitivity in overweight hyperinsulinemic adults

BACKGROUND

Epidemiologic studies have found whole-grain intake to be inversely associated with the risk of type 2 diabetes and heart disease.

OBJECTIVE

We tested the hypothesis that whole-grain consumption improves insulin sensitivity in overweight and obese adults.

DESIGN

This controlled experiment compared insulin sensitivity between diets (55% carbohydrate, 30% fat) including 6-10 servings/d of breakfast cereal, bread, rice, pasta, muffins, cookies, and snacks of either whole or refined grains. Total energy needs were estimated to maintain body weight. Eleven overweight or obese [body mass index (in kg/m(2)): 27-36] hyperinsulinemic adults aged 25-56 y participated in a randomized crossover design. At the end of each 6-wk diet period, the subjects consumed 355 mL (12 oz) of a liquid mixed meal, and blood samples were taken over 2 h. The next day a euglycemic hyperinsulinemic clamp test was administered.

RESULTS

Fasting insulin was 10% lower during consumption of the whole-grain than during consumption of the refined-grain diet (mean difference: -15 +/- 5.5 pmol/L; P = 0.03). After the whole-grain diet, the area under the 2-h insulin curve tended to be lower (-8832 pmol.min/L; 95% CI: -18720, 1062) than after the refined-grain diet. The rate of glucose infusion during the final 30 min of the clamp test was higher after the whole-grain diet (0.07 x 10(-4) mmol.kg(-1).min(-1) per pmol/L; 95% CI: 0.003 x 10(-4), 0.144 x 10(-4)).

CONCLUSION

Insulin sensitivity may be an important mechanism whereby whole-grain foods reduce the risk of type 2 diabetes and heart disease.

Effect of diet on adipose tissue and skeletal muscle VLDL receptor and LPL: implications for obesity and hyperlipidemia

This study was designed to examine the effect of a high-fat (primarily saturated), refined-carbohydrate (sucrose) diet (HFS), which is known to induce obesity and hyperlipidemia, on adipose tissue and skeletal muscle lipoprotein lipase (LPL) and very-low density lipoprotein receptor (VLDL-R) protein expressions. Female Fischer rats were placed on either a HFS or a low-fat, complex-carbohydrate (LFCC) diet for 22 months beginning at 2 months of age. After 20 months, a subgroup of the HFS rats were switched to the LFCC diet for 2 months (HFS/LFCC). Body weight, feed efficiency, plasma total cholesterol, VLDL-C, low-density lipoprotein cholesterol (LDL-C) and triglyceride (TG) concentrations and LDL-C to high-density lipoprotein cholesterol ratio were all significantly raised by the HFS diet and improved by conversion to the LFCC diet. Adipose tissue heparin-releasable, extractable and total LPL activity expressed per cell were significantly increased in the HFS-fed group. However, LPL protein abundance normalized against total cellular protein was unchanged in the HFS group. This observation is consistent with the presence of adipose tissue hypertrophy. Skeletal muscle LPL protein abundance and heparin-releasable activity were reduced by the HFS diet and improved after switching to the LFCC diet. Both adipose tissue and skeletal muscle VLDL-R protein levels were significantly reduced by the HFS diet and increased after conversion to the LFCC diet. We conclude that an HFS diet induces changes in LPL and VLDL-R in a manner which favors shunting of dietary fat from skeletal muscle to adipose tissue and decreases TG-rich lipoprotein clearance contributing to increased plasma lipids and obesity. Conversion to a LFCC diet can ameliorate the dyslipidemia and tissue changes induced by long-term HFS diet consumption.