Fiber intake of normal weight, moderately obese and severely obese subjects

Role of diet and exercise in aging, Alzheimer's disease, and other chronic diseases

Alzheimer's disease (AD) is a progressive neurodegenerative disease, characterized by memory loss and multiple cognitive impairments. Genetic mutations cause a small proportion (1-2%) of early-onset AD, with mutations in amyloid precursor protein (APP), presenilin 1 (PS1) and presenilin 2 (PS2). Major contributing factors of late-onset AD are ApoE4 genotype, traumatic brain injury, diabetes, obesity, hypertension, cardiovascular conditions, in addition to lifestyle factors, such as unhealthy diet and lack of physical exercise. Disease progression can be delayed and/or prevented to a greater extent by adopting healthy lifestyle with balanced and antioxidant enriched diet and daily exercise. The interaction and interplay of diet, exercise, age, and pharmacological interventions holds a crucial role in the progression, pathogenesis and management of AD and its comorbidities, including diabetes, obesity, hypertension and cardiovascular conditions. Antioxidant enriched diet contributes to brain health, glucose control, weight management, and cardiovascular well-being. Regular exercise removes toxins including free radicals and enhances insulin sensitivity, and supports cardiovascular function. In the current article, we discussed, the role of diet, and exercise in aging, AD and other conditions including diabetes, obesity, hypertension, cardiovascular conditions. This article also highlights the impact of medication, socioeconomic and lifestyle factors, and pharmacological interventions. These aspects were discussed in different races and ethnic groups in Texas, and the US.

Effectiveness of Fiber Supplementation for Constipation, Weight Loss, and Supporting Gastrointestinal Function: A Narrative Review of Meta-Analyses

Objective

The purpose of this narrative review is to determine whether published meta-analyses support the use of fiber supplementation in the treatment of constipation, weight loss, and dietary support for gastrointestinal disorders such as irritable bowel syndrome (IBS) and inflammatory bowel disease.

Methods

A PubMed search from January 1, 1980, to July 31, 2019, was conducted with the following search strategy: (fiber OR fibre) AND (meta-analysis OR systematic review) AND (constipation OR body weight OR obesity OR irritable bowel syndrome OR inflammatory bowel disease). Meta-analyses that provided quantitative statistical analysis with a measured effect size were retrieved and accepted into this review. The following was extracted and entered into an Excel spreadsheet: number of publications included in the meta-analysis, number of total participants, fiber type and daily dose, pooled treatment effects for clinical endpoints, or summary relative risks.

Results

Eighteen meta-analyses support dietary fiber supplementation for patients with constipation, weight loss, and IBS, but the significant heterogeneity and publication bias undermine the support for using dietary fiber supplementation in these conditions.

Conclusion

This narrative review of meta-analyses finds some benefits for recommending fiber supplementation to patients with constipation, obesity, and IBS, but significant heterogeneity and publication bias undermine this support.

Long Term Effect of Fibre Supplement and Reduced Energy Intake on Body Weight and Blood Lipids in Overweight Subjects

A weight-reducing potential has been ascribed to high dietary fibre intake. To investigate the practical reliability of this hypothesis, fifty-three moderately overweight females (BMI > 27.5 kg/m2) on reduced energy intake (1200kcal/day) were treated for 24 weeks with a fibre supplement on a randomly, double-blind, placebo-controlled basis. The fibre was administered as an initial dose of 6 g and a maintenance dose of 4 g. Body weight and blood pressure were recorded weekly during the first 3 months and thereafter every second week. Blood samples were drawn at start and at end of the study. Initial body weights were 75.6 ± 1.6 kg in the fibre group versus 75.5 ± 1.6 kg in the placebo group. After treatment, mean weight loss in the fibre group was 8.0 kg versus 5.8 kg in the placebo group (p < 0.05). Systolic and diastolic blood pressures were significantly reduced in both groups without differences between the groups. Serum concentrations of cholesterol, triglycerides and uric acid were significantly reduced in the group with reduced energy intake, whereas no additional effect was observed when fibre was supplemented. Serum concentrations of potassium and sodium did not change significantly. The results suggest that a dietary fibre supplement in combination with a hypocaloric diet is of value as an adjunct in the management of overweight.

Intakes and Food Sources of Dietary Fibre and Their Associations with Measures of Body Composition and Inflammation in UK Adults: Cross-Sectional Analysis of the Airwave Health Monitoring Study

The purpose of this study was to investigate the associations between intakes of fibre from the main food sources of fibre in the UK diet with body mass index (BMI), percentage body fat (%BF), waist circumference (WC) and C-reactive protein (CRP). Participants enrolled in the Airwave Health Monitoring Study (2007-2012) with 7-day food records (n = 6898; 61% men) were included for cross-sectional analyses. General linear models evaluated associations across fifths of fibre intakes (total, vegetable, fruit, potato, whole grain and non-whole grain cereal) with BMI, %BF, WC and CRP. Fully adjusted analyses showed inverse linear trends across fifths of total fibre and fibre from fruit with all outcome measures (ptrend < 0.0001). Vegetable fibre intake showed an inverse association with WC (ptrend 0.0156) and CRP (ptrend 0.0005). Fibre from whole grain sources showed an inverse association with BMI (ptrend 0.0002), %BF (ptrend 0.0007) and WC (ptrend 0.0004). Non-whole grain cereal fibre showed an inverse association with BMI (Ptrend 0.0095). Direct associations observed between potato fibre intake and measures of body composition and inflammation were attenuated in fully adjusted analyses controlling for fried potato intake. Higher fibre intake has a beneficial association on body composition, however, there are differential associations based on the food source.

The effect of soluble fiber dextrin on postprandial appetite and subsequent food intake in healthy adults

OBJECTIVES

This crossover study investigated the effect of consuming a beverage that contains soluble fiber dextrin (SFD) on appetite and food intake in adults to test the hypothesis that beverages that contain 10 or 20 g of fiber from SFD would be more satiating than the control beverage.

METHODS

Forty-one participants consumed lunch with a beverage that contained 0 g, 10 g, or 20 g of fiber from SFD. Appetite questionnaires were completed and blood samples collected immediately before lunch and at regular intervals over the following 150 min. Then, participants were provided with an afternoon snack and the amount eaten was recorded. Participants then left the laboratory but were asked to complete hourly appetite questionnaires and record food intake for the remainder of the day.

RESULTS

Consuming SFD had no effect on appetite over the 150 min after consumption of the lunch meal (P > 0.05). Hunger and desire to eat were lower and fullness higher after consumption of the beverage that contained 20 g of fiber from SFD (P < 0.05) after participants left the laboratory. There was no effect of consuming SFD on food intake at the snack meal or for the rest of the day (P > 0.05). Plasma glucose-dependent insulintropic polypeptide was lower during the 150 min after consumption of 20 g fiber from the SFD beverage (P < 0.05). There was no treatment effect on the plasma concentration of other biomarkers of glycemic response or appetite (P > 0.05).

CONCLUSIONS

Overall, the study results did not show an effect of SFD on appetite, food intake, and plasma markers of appetite for the first 150 min postconsumption. Further research is required to quantify how SFD influences appetite several hours after consumption.

Dietary Fiber Intake among Normal-Weight and Overweight Female Health Care Workers: An Exploratory Nested Case-Control Study within FINALE-Health

Socioeconomic factors affect choice of diet, that is, dietary fiber intake. Underreporting of food consumption in diet surveys has been reported higher in low-income, low-education groups compared to high-income, high-education groups. This paper examines in a socioeconomic homogenous low-income low-education group of females the relation between dietary fiber intake and overweight and scrutinizes if the level of underreporting is equally large in normal-weight and overweight groups. Thirty-four female health care workers classified as either normal-weight (N = 18) or obese (N = 16) based on BMI, fat percentage, and waist circumference participated. A detailed food-diary was used to record their dietary intake in 9 days. Average dietary fiber intake in the normal-weight group was 2.73 +/− 0.65 g/MJ, while it was 2.15 +/− 0.64 g/MJ for the women in the obese group. In both groups, the overall food intake was underreported. In spite of a significantly lower dietary fiber intake in the obese group, the present population of women working within health care all showed an overall low dietary fiber intake and a general underreporting of food intake. These results indicate a clear need for dietary advice especially on fiber intake to increase general health and decrease weight.

Effect of Consuming Oat Bran Mixed in Water before a Meal on Glycemic Responses in Healthy Humans-A Pilot Study

Background: Viscous dietary fibers including oat β-glucan are one of the most effective classes of functional food ingredients for reducing postprandial blood glucose. The mechanism of action is thought to be via an increase in viscosity of the stomach contents that delays gastric emptying and reduces mixing of food with digestive enzymes, which, in turn, retards glucose absorption. Previous studies suggest that taking viscous fibers separate from a meal may not be effective in reducing postprandial glycemia. Methods: We aimed to re-assess the effect of consuming a preload of a commercially available oat-bran (4.5, 13.6 or 27.3 g) containing 22% of high molecular weight oat β-glucan (O22 (OatWell^®22)) mixed in water before a test-meal of white bread on glycemic responses in 10 healthy humans. Results: We found a significant effect of dose on blood glucose area under the curve (AUC) (p = 0.006) with AUC after 27.3 g of O22 being significantly lower than white bread only. Linear regression analysis showed that each gram of oat β-glucan reduced glucose AUC by 4.35% ± 1.20% (r = 0.507, p = 0.0008, n = 40) and peak rise by 6.57% ± 1.49% (r = 0.582, p < 0.0001). Conclusion: These data suggest the use of oat bran as nutritional preload strategy in the management of postprandial glycemia.

Effects of the Polysaccharide from the Sporophyll of Brown Alga Undaria Pinnatifida on Serum Lipid Profile and Fat Tissue Accumulation in Rats Fed a High-Fat Diet

We investigated the effects of the polysaccharide from the sporophyll of a selected brown alga Undaria pinnatifida on serum lipid profile, fat tissue accumulation, and gastrointestinal transit time in rats fed a high-fat diet. The algal polysaccharide (AP) was prepared by the treatment of multiple cellulase-producing fungi Trichoderma reesei and obtained from the sporophyll with a yield of 38.7% (dry basis). The AP was mostly composed of alginate and fucoidan (up to 89%) in a ratio of 3.75:1. The AP was added to the high-fat diet in concentrations of 0.6% and 1.7% and was given to male Sprague-Dawley rats (5-wk-old) for 5 wk. The 1.7% AP addition notably reduced body weight gain and fat tissue accumulation, and it improved the serum lipid profile, including triglycerides, total cholesterol, and very low-density lipoprotein-cholesterol. The effects were associated with increased feces weight and shortened gastrointestinal transit time. In addition, the lipid peroxidation of the liver was decreased in both groups.

Changes in Intake of Fruits and Vegetables and Weight Change in United States Men and Women Followed for Up to 24 Years: Analysis from Three Prospective Cohort Studies

BACKGROUND

Current dietary guidelines recommend eating a variety of fruits and vegetables. However, based on nutrient composition, some particular fruits and vegetables may be more or less beneficial for maintaining or achieving a healthy weight. We hypothesized that greater consumption of fruits and vegetables with a higher fiber content or lower glycemic load would be more strongly associated with a healthy weight.

METHODS AND FINDINGS

We examined the association between change in intake of specific fruits and vegetables and change in weight in three large, prospective cohorts of 133,468 United States men and women. From 1986 to 2010, these associations were examined within multiple 4-y time intervals, adjusting for simultaneous changes in other lifestyle factors, including other aspects of diet, smoking status, and physical activity. Results were combined using a random effects meta-analysis. Increased intake of fruits was inversely associated with 4-y weight change: total fruits -0.53 lb per daily serving (95% CI -0.61, -0.44), berries -1.11 lb (95% CI -1.45, -0.78), and apples/pears -1.24 lb (95% CI -1.62, -0.86). Increased intake of several vegetables was also inversely associated with weight change: total vegetables -0.25 lb per daily serving (95% CI -0.35, -0.14), tofu/soy -2.47 lb (95% CI, -3.09 to -1.85 lb) and cauliflower -1.37 lb (95% CI -2.27, -0.47). On the other hand, increased intake of starchy vegetables, including corn, peas, and potatoes, was associated with weight gain. Vegetables having both higher fiber and lower glycemic load were more strongly inversely associated with weight change compared with lower-fiber, higher-glycemic-load vegetables (p < 0.0001). Despite the measurement of key confounders in our analyses, the potential for residual confounding cannot be ruled out, and although our food frequency questionnaire specified portion size, the assessment of diet using any method will have measurement error.

CONCLUSIONS

Increased consumption of fruits and non-starchy vegetables is inversely associated with weight change, with important differences by type suggesting that other characteristics of these foods influence the magnitude of their association with weight change.

Food groups and weight gain in Japanese men

Identifying subjects at high risk of weight gain according to consumption of food groups is important for individualizing nutritional education, but prospective studies of this issue have been few. We determined whether intake of specific food groups could predict future weight gain. We evaluated data from health checkups on 1236 Japanese men aged 28 to 87 years in 2005 and 2006. Dietary intake was assessed by a 24-h dietary recall at baseline. Weight change was measured after 1 year. Weight increased in 44.7% (n = 553) of participants. Multivariate regression analysis involving many food groups showed a significant association between sugar intake and weight gain after adjustment for age, body mass index (BMI), total energy intake, alcohol, smoking and regular physical exercise (β = 0.22, P = 0.04). The effect of intake of 'fats and oils' was significant when adjusted for age and BMI, however, it became insignificant after adjustment for age, BMI and total energy intake. Intake of sugar, which was evaluated as a food group, was predictive of subsequent weight gain among Japanese men, even after adjustment for many confounders. This corroborates the evidence so far concerning the links between sugar intake and weight gain. Further long-term research is required to give robust recommendation to the public.

Dietary fibers and cardiometabolic diseases

The high prevalence of cardiovascular disease (CVD) is largely attributable to the contemporary lifestyle that is often sedentary and includes a diet high in saturated fats and sugars and low ingestion of polyunsaturated fatty acids (PUFAs), fruit, vegetables, and fiber. Experimental data from both animals and humans suggest an association between increased dietary fiber (DF) intakes and improved plasma lipid profiles, including reduced low density lipoprotein cholesterol (LDL-C) concentrations. These observations underline that the intake of DF may protect against heart disease and stroke.

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.

Fiber, protein, and lupin-enriched foods: role for improving cardiovascular health

Cardiovascular diseases (CVD) are the leading cause of death globally (World Health Organisation, 2011). Many of the risk factors for CVD are modifiable, including overweight and obesity. Numerous strategies have been proposed to fight CVD, with a special focus being placed on dietary interventions for weight management. The literature suggests that two nutrients, fiber and protein, may play significant roles in weight control and hence cardiovascular health. Increasing both protein and fiber in the diet can be difficult because popular low-carbohydrate and high-protein diets tend to have considerably low-fiber intakes (Slavin, 2005). One approach to obtain both is to develop functional foods using unique ingredients. Lupin flour is a novel food ingredient derived from the endosperm of lupin. It contains 40-45% protein, 25-30% fiber, and negligible sugar and starch (Petterson and Crosbie, 1990). Research conducted to date reveals that lupin-enriched foods, which are naturally high in protein and fiber, may have a significant effect on CVD risk factors. This review explores whether there is a role for fiber-, protein-, and lupin-enriched foods in improving cardiovascular health.

Dietary fiber in the diets of urban Tunisian women: association of fiber intake with BMI, waist circumference and blood chemistry: preliminary study

BACKGROUND

The change of the way of life and the food practices in Tunisia due inter alia to the improvement of the socioeconomic conditions induced low fuel consumption of food with significant nutritional interest such as those rich in food fibres which have positive effects on the reduction and the prevention of some complications of the metabolic diseases such as the obesity whose prevalence among Tunisian women is increasingly high.

OBJECTIVE

We assessed the association between the mean daily fiber intake and anthropometric parameters, the serum lipid profile and the serum glucose concentration among urban Tunisian women.

METHODS

We conducted a 7-day food weighing method among 260 women of which 60 are obese (BMI > 30 kg/m(2)). The weighing method was done by trained and experienced workers in the National Institute of Nutrition of Tunisia. All the results were treated with the (Bilnut) software (1991 version) to which a list of 235 special Tunisian foods was added. We calculated their mean daily fiber intake and we prospectively evaluated the correlations between it and the BMI, the waist circumference, total plasma cholesterol, HDL-cholesterol, triglyceridemia and glycaemia.

RESULTS

Obese women are found to consume less fiber than non-obese women (21.73 ± 3.25 g/day vs 26.25 ± 2.7 g/day; P<0.0001). Very high and significant correlations were observed between dietary fiber intake and the parameters investigated: BMI (r=-0.709, P<0.0001), waist circumference (r=-0.790; P<0.0001), total plasma cholesterol (r=-0.488; P<0.0001), triglyceridemia (r=-0.741; P<0.0001) and glycaemia (r=-0.557, P<0.0001). However, we find a positive but a non significant correlation with the HDL-cholesterol and the mean daily fiber intake (r=0.309; P=0.02).

CONCLUSIONS

This study provides additional support to the inverse association between fiber consumption and weight gain, the serum lipid profiles, the glycaemia and the waist circumference. Our findings emphasizes the relevance of increased the intakes of fiber from varied sources that may help avoid weight gain among obese adults.

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.

Effects of short-chain fructooligosaccharides on satiety responses in healthy men and women

In view of a dramatic increase in the incidence of obesity, the present study examined the appetite effects of a functional fiber as a potential dietary intervention. Fiber may increase satiety. Satiety effects also may be linked to colonic fermentation. Short-chain fructooligosaccharide (scFOS) are fermentable fibers that can be added to foods to influence these actions. The primary objective of this study was to determine if scFOS affects satiety and hunger and has an additive effect on food intake. Using a double-blind crossover design, 20 healthy subjects were assigned to consume two separate doses of 0 g, 5 g, or 8 g of scFOS. The first dose was mixed into a hot cocoa beverage and served with a breakfast meal of a bagel and cream cheese. A beverage was used in the test meal due to the ease with which scFOS can be added to this medium. Satiety was assessed with visual analogue scales (VASs) at 0, 15, 30, 45, 60, 90, 120, 180, and 240 min. Ad libitum food intake was measured at a lunch meal provided at the test site at 240 min. Subjects then recorded their food intake over the remainder of the 24-h study day. The second dose of scFOS was consumed in the form of 3 solid, chocolate-flavored chews (51-67 total kcal) without additional food or drink, 2h prior to the subject's dinner meal. Breath hydrogen measures were collected prior to the breakfast test meal (0 min) and the ad libitum lunch (240 min). Gastrointestinal tolerance was evaluated over the course of the 24-h study day using VAS. All treatments were well tolerated. No differences in subjective satiety over the morning, or food intake at lunch, were found. Over the remainder of the day, the high dose of scFOS reduced food intake in women, but increased food intake in men, suggesting a gender difference in the longer-term response. Breath hydrogen, used as a marker of fermentation, increased in a dose-dependent manner. These results indicate that scFOS undergoes fermentation within 240 min; however, acceptable amounts of scFOS did not enhance acute satiety or hunger.

Dietary fiber supplements: effects in obesity and metabolic syndrome and relationship to gastrointestinal functions

Dietary fiber is a term that reflects a heterogeneous group of natural food sources, processed grains, and commercial supplements. Several forms of dietary fiber have been used as complementary or alternative agents in the management of manifestations of the metabolic syndrome, including obesity. Not surprisingly, there is a great variation in the biological efficacy of dietary fiber in the metabolic syndrome and body weight control. Diverse factors and mechanisms have been reported as mediators of the effects of dietary fiber on the metabolic syndrome and obesity. Among this array of mechanisms, the modulation of gastric sensorimotor influences appears to be crucial for the effects of dietary fiber but also quite variable. This report focuses on the role, mechanism of action, and benefits of different forms of fiber and supplements on obesity and the metabolic syndrome, glycemia, dyslipidemia, and cardiovascular risk and explores the effects of dietary fiber on gastric sensorimotor function and satiety in mediating these actions of dietary fiber.

Effects of fruit consumption on body mass index and weight loss in a sample of overweight and obese dieters enrolled in a weight-loss intervention trial

OBJECTIVE

Fruit and vegetable consumption is an important part of a healthy diet and assumed to aid in the reduction of energy intake and body weight. Fruits and vegetables may display differential effects on weight and weight loss; however, the effects of the two food groups have rarely been investigated separately.

METHODS

The present study focused on the effects of fruit consumption on body weight and weight loss in a sample of 77 overweight and obese dieters enrolled in an intervention program. Food consumption was assessed at baseline by food diaries and after the introduction of nutrition software through electronic food records. Body weight and additional physiologic outcomes were assessed three times, once before the intervention and again at the 3- and 6-mo follow-ups.

RESULTS

Vegetable and fruit consumption differed in their associations with body weight and weight loss. Although vegetable consumption increased as a result of the intervention (P<0.01), fruit consumption did not. However, only fruit consumption was associated with body mass index, showing an inverse relation with body weight in cross-sectional and longitudinal analyses (r=-0.27 to -0.44). The relation between fruit consumption and body weight remained significant after controlling for age, gender, physical activity level, and daily macronutrient consumption (DeltaR(2)=0.06-0.13). Further, increases in fruit consumption were associated with subsequent weight loss, controlling for the same covariates (DeltaR(2)=0.05-0.07).

CONCLUSION

The results indicate unique contributions of fruit consumption to the management of body weight and indicate that a separation of effects for fruit and vegetable food groups may be warranted.

Alginate reduces the increased uptake of cholesterol and glucose in overweight male subjects: a pilot study

Dietary fibers are of particular interest in the prevention and management of obesity and consequent pathologies. Among the proposed mechanisms of action of fiber is the modulation of nutrient uptake from the small intestine. We have used a crossover study design in human subjects to monitor the uptake of glucose, cholesterol, and triacylglycerols in human subjects with normal and high body mass index. Our data demonstrate that uptakes of glucose, triacylglycerols, and cholesterol are all increased with increasing body fat. We demonstrate that treatment with a 1.5-g dose of a strong-gelling alginate may restore uptake of cholesterol and glucose to the levels of healthy subjects. These data indicate a potential therapeutic application of gelling fibers.

A Review of the Role of Soluble Fiber in Health with Specific Reference to Wheat Dextrin

Dietary fiber is widely recognized to have a beneficial role in overall health, but only at adequate levels (25 − 38 g/day for healthy adults). Wheat dextrin in particular is a soluble fiber that can easily be added to the diet and is widely used in the food industry. There is some debate about whether increased intake of soluble fibers leads to health benefits. This paper reviews the evidence regarding the physiological effects and potential health benefits of the addition of soluble dietary fibers, with specific reference to wheat dextrin, based on a search of PubMed. The evidence suggests that soluble fibers help to regulate the digestive system, may increase micronutrient absorption, stabilize blood glucose and lower serum lipids, may prevent several gastrointestinal disorders, and have an accepted role in the prevention of cardiovascular disease. It is concluded that supplementation with soluble fibers (e.g. wheat dextrin) may be useful in individuals at risk of a lower than recommended dietary fiber intake.

The acute effects of psyllium on postprandial lipaemia and thermogenesis in overweight and obese men

Overweight and obesity is one of the risk factors for developing CVD. At present, very little is known about the acute effects of dietary fibre on lipids, glucose and insulin, resting energy expenditure and diet-induced thermogenesis in overweight and obese individuals. This study examined the postprandial metabolic effects of dietary fibre in overweight and obese men. Ten overweight and obese men consumed a mixed meal accompanied by either a high-fibre or low-fibre supplement on two separate visits, in a random order, 1 week apart. Two isoenergetic breakfast meals with similar composition were consumed by ten overweight/obese men. The meals contained either a low (3 g) or high (15 g) amount of fibre, low-fibre meal (LFM) and high-fibre meal (HFM) respectively. Analysis was carried out using paired t test and ANOVA. Serum TAG incremental area under the curve during 6 h of the postprandial period was significantly lower after the consumption of HFM compared with LFM. At the first hour of the postprandial period, plasma apo B48 concentration after consumption of HFM was significantly lower compared with LFM. The resting energy expenditure and diet-induced thermogenesis after both meals was similar during 6 h of the postprandial period. Collectively, these findings suggest that a single acute dose of dietary fibre in the form of psyllium supplement can decrease arterial exposure to TAG and modify chylomicron responses in the postprandial period.

Effects of dietary fibers on weight gain, carbohydrate metabolism, and gastric ghrelin gene expression in mice fed a high-fat diet

Diets that are high in dietary fiber are reported to have substantial health benefits. We sought to compare the metabolic effects of 3 types of dietary fibers -- sugarcane fiber (SCF), psyllium (PSY), and cellulose (CEL) -- on body weight, carbohydrate metabolism, and stomach ghrelin gene expression in a high-fat diet-fed mouse model. Thirty-six male mice (C57BL/6) were randomly divided into 4 groups that consumed high-fat diet alone (HFD) or high-fat diet containing 10% SCF, PSY, and CEL, respectively. After baseline measurements were assessed for body weight, plasma insulin, glucose, leptin, and glucagon-like peptide 1 (GLP-1), animals were treated for 12 weeks. Parameters were reevaluated at the end of study. Whereas there was no difference at the baseline, body weight gains in the PSY and SCF groups were significantly lower than in the CEL group at the end of study. No difference in body weight was observed between the PSY and SCF animals. Body composition analysis demonstrated that fat mass in the SCF group was considerably lower than in the CEL and HFD groups. In addition, fasting plasma glucose and insulin and areas under the curve of intraperitoneal glucose tolerance test were also significantly lower in the SCF and PSY groups than in the CEL and HFD groups. Moreover, fasting plasma concentrations of leptin were significantly lower and GLP-1 level was 2-fold higher in the SCF and PSY mice than in the HFD and CEL mice. Ghrelin messenger RNA levels of stomach in the SCF group were significantly lower than in the CEL and HFD groups as well. These results suggest differences in response to dietary fiber intake in this animal model because high-fat diets incorporating dietary fibers such as SCF and PSY appeared to attenuate weight gain, enhance insulin sensitivity, and modulate leptin and GLP-1 secretion and gastric ghrelin gene expression.

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.

Effect of two doses of a mixture of soluble fibres on body weight and metabolic variables in overweight or obese patients: a randomised trial

The aim of the study was to compare the effect of the administration of a mixture of fibres on body weight-loss, satiety, lipid profile and glucose metabolism. We included 200 overweight or obese patients in a parallel, double-blind, placebo-controlled clinical trial, who were randomised to receive, in the context of an energy-restricted diet for a period of 16 weeks, a mixed fibre dose (3 g Plantago ovata husk and 1 g glucomannan) twice (b.i.d. group) or three times daily (t.i.d. group) or placebo. Weight change was the primary efficacy endpoint. Satiety, dietary compliance, lipid profile, glucose tolerance, insulin resistance and high-sensitivity C-reactive protein were secondary endpoints. Weight loss tended to be higher after both doses of fibre (-4.52 (SD 0.56) and -4.60 (SD 0.55) kg) than placebo (-0.79 (SD 0.58) kg); the differences in changes between groups were not statistically significant. Postprandial satiety increased in both fibre groups compared to the placebo. The differences between groups in LDL-cholesterol levels were significant (P = 0.03), with greater reductions in the two fibre-supplemented groups (-0.38 (SD 0.10) and -0.24 (SD 0.09) mmol/l in the b.i.d. and t.i.d. groups v. -0.06 (SD 0.09) mmol/l in placebo group). A similar pattern was observed for changes in total cholesterol:HDL-cholesterol and HDL-cholesterol:LDL-cholesterol ratios. Interventions were well tolerated and had no effects on HDL-cholesterol, glucose and insulin concentrations, glucose tolerance or high-sensitivity C-reactive protein. In conclusion, a 16-week dietary supplement of soluble fibre in overweight or obese patients was well tolerated, induced satiety and had beneficial effects on some CVD risk factors, the most important of which was a significant decrease in plasma LDL-cholesterol concentrations.

Associations of dietary sugar and glycemic index with adiposity and insulin dynamics in overweight Latino youth

BACKGROUND

Few studies have examined the relation between dietary carbohydrate quality, adiposity, and insulin dynamics in children.

OBJECTIVE

The objective of the study was to determine which aspects of dietary carbohydrate, specifically dietary sugar, fiber, glycemic index, or glycemic load, are associated with adiposity and insulin dynamics in overweight Latino children.

DESIGN

We examined 120 overweight Latino children (10-17 y old) with a family history of type 2 diabetes. Dietary intake was determined by repeated 24-h diet recalls. Adiposity was assessed by using total-body dual-energy X-ray absorptiometry. Insulin dynamics [insulin sensitivity (SI), acute insulin response, and disposition index (an index of beta-cell function)] were measured by using a frequently sampled intravenous-glucose-tolerance test.

RESULTS

After adjustment for covariates, total sugar (g/d) was positively correlated with body mass index (BMI; in kg/m(2)), BMI z scores, and total fat mass (r = 0.20, r = 0.22, and r = 21, respectively; P < 0.05) and negatively correlated with SI and disposition index (r = -0.29 and r = -0.24, respectively; P < 0.05). Dietary fiber, glycemic index, and glycemic load were not significantly correlated with adiposity or insulin dynamics before or after control for covariates. Regression analyses showed that total sugar intake explained an additional 3.4%, 4.6%, and 2.4% of the variance in BMI, BMI z scores, and total fat mass, respectively, and an additional 5.6% and 4.8% of the variance in SI and disposition index (P < 0.05), respectively, after control for covariates.

CONCLUSION

In this cohort, total sugar intake, rather than glycemic index or glycemic load, was associated with higher adiposity measures, lower SI, and lower measures of insulin secretion.

Dietary fibre, nuts and cardiovascular diseases

Dietary fibre has a range of metabolic health benefits. Through a variety of mechanisms, dietary fibre, and the viscous variety in particular, slows down gastric emptying and intestinal transit, decreases the rate of intestinal carbohydrate absorption, and increases faecal bile acid excretion. Therefore, consumption of some types of soluble fibre can enhance satiety, which is associated with a lower BMI, and reduce blood cholesterol and the postprandial glucose response. Surprisingly, the consumption of insoluble fibre from whole grains, though metabolically inert, has been associated with a reduction in the risk of developing coronary heart disease and diabetes in epidemiological studies. The likely reason is that whole grains, like nuts, legumes and other edible seeds, contain many bioactive phytochemicals and various antioxidants. After cereals, nuts are the vegetable foods that are richest in fibre, which may partly explain their benefit on the lipid profile and cardiovascular health.

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.

Biomedical issues of dietary fiber beta-glucan

Beta-glucan is a polysaccharide in the form of fiber and the main element of fiber in grains such as barley, oats, yeast and mushrooms. Many studies have examined the efficacy of beta-glucan in terms of the lipid lowering effects, blood sugar reduction, weight reduction, immune modulator, and anticarcinogenic effect. However, there is no comprehensive review article on the biomedical issues regarding beta-glucan. The authors searched for systematic reviews and clinical experiments for each relevant topic and reviewed the biomedical effects of beta-glucan, for the purpose of developing research strategies for the future.

Association of fiber intake and fruit/vegetable consumption with weight gain in a Mediterranean population

OBJECTIVE

We assessed the association between fiber intake and fruit/vegetable consumption with the likelihood of weight gain in the previous 5 y in a Mediterranean population.

METHODS

We conducted a cross-sectional analysis of participants (5094 men and 6613 women) in a multipurpose prospective cohort (Seguimiento Universidad de Navarra Study). Diet was measured by using a semiquantitative food-frequency questionnaire that was previously validated in Spain. We calculated the odds ratios of weight gain in the previous 5 y according to quintiles of energy-adjusted fiber intake and quintiles of energy-adjusted of fruit/vegetable consumption. We also considered the joint exposure to fiber intake and fruit/vegetable consumption.

RESULTS

Multivariate-adjusted odds ratios for weight gain across quintiles 1 to 5 of fiber intake were 1.00 (reference), 0.86, 0.86, 0.70, and 0.52 (P for trend < 0.001) among men and 1.00 (reference), 0.99, 1.08, 1.05, and 0.72 (P for trend = 0.005) among women. We also observed a significant inverse association between total fruit/vegetable consumption and weight gain, but only among men (adjusted odds ratios, 0.78, 0.89, 0.70, and 0.54 for quintiles 2 to 5, P for trend < 0.001). The inverse association between fruit/vegetable consumption and weight gain in the previous 5 y was more evident among those with a high intake of total fiber, and the benefit of total fiber was more evident among those with a high consumption of fruits and vegetables.

CONCLUSIONS

This study provides additional support to the inverse association between fiber or fruit/vegetable consumption and weight gain, thus emphasizing the importance of replacing some dietary compounds by such foods and fiber-rich products, which may help to avoid weight gain.

Long-term gastrointestinal tolerance of NUTRIOSE®FB in healthy men

OBJECTIVE

To determine the gastrointestinal (GI) tolerance of NUTRIOSE FB in men.

DESIGN

A randomized, placebo-controlled, parallel, double-blind study.

SETTING

The metabolic ward of TNO Quality of Life.

SUBJECTS

Forty-eight subjects started the study: 16 men participated in one of the three treatments. SUBJECTS consumed either 22.5 g of pure maltodextrin (Glucidex 6), or 30 or 45 g of the dextrin NUTRIOSE FB daily for 4-5 weeks. Forty-three subjects completed the study (age: 34.7 +/- 8.2 years; BMI 24.9 +/- 3.3 kg m2).

MEASUREMENTS

Tolerance of NUTRIOSE FB was examined with a GI complaints questionnaire; effectiveness on colonic flora was examined by faecal analysis; fermentation by breath hydrogen excretion measurement. Furthermore, the effect on body weight (BW), energy intake and blood parameters were examined in the study.

RESULTS

Both doses of NUTRIOSE FB were very well tolerated and GI complaints hardly differed from the placebo treatment. No diarrhoea was reported due to NUTRIOSE FB supplementation. In the course of the study, some habituation and adaptation of GI symptoms were found. Fermentation and faecal characteristics (pH and enzyme activity) were significantly positively affected with NUTRIOSE FB treatment. Body weight in both NUTRIOSE FB groups remained stable over time, although the placebo-treated group showed a small increase in BW (Deltaday35-1 0.8 +/- 1.0 kg) (P = 0.07). However, total food intake and macronutrient composition of the diet remained the same throughout the study. No significant differences were found between the three treatment groups in hunger and satiety scores and food preferences.

CONCLUSIONS

Long-term supplementation of 30 or 45 g of the dextrin NUTRIOSE FB per day was well tolerated, and may act as a pre-biotic supplement.

SPONSORSHIP

TNO Quality of Life was assigned by Roquette Frères to perform the study.

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.

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.

Becoming Proactive With the Whole-Grains Message

Whole-grain foods have always been considered a healthy part of the diet. Only recently have epidemiologic and other data shown that whole grains have a role in preventing cardiovascular disease, diabetes, some types of cancer, and even obesity. What nearly all consumers and most health professionals fail to realize is that whole grains deliver as many if not more phytochemicals and antioxidants than do fruits and vegetables. Healthy People 2010 (DHHS) recommends 3 servings of whole grains per day. Because the average intake in the United States is less than 1 serving per day, health professionals must mount an active campaign to help consumers better understand the important health benefits of whole grains and work to increase their intake in the diet.

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.

Prospective study of the association of changes in dietary intake, physical activity, alcohol consumption, and smoking with 9-y gain in waist circumference among 16 587 US men

BACKGROUND

Although it is known that abdominal obesity increases the risk of chronic diseases, prospective data examining the relation between lifestyle factors and the accumulation of abdominal adipose tissue are sparse.

OBJECTIVE

The objective of the study was to determine the associations of changes in diet, physical activity, alcohol consumption, and smoking with 9-y waist gain among US men.

DESIGN

A prospective cohort comprised 16 587 US men aged 40-75 y at baseline in 1986. Data on lifestyle factors were provided periodically with the use of self-reported questionnaires, and participants measured and reported their waist circumference in 1987 and 1996.

RESULTS

In multivariate analyses, a 2% increment in energy intake from trans fats that were isocalorically substituted for either polyunsaturated fats or carbohydrates was significantly associated with a 0.77-cm waist gain over 9 y (P < 0.001 for each comparison). An increase of 12 g total fiber/d was associated with a 0.63-cm decrease in waist circumference (P < 0.001), whereas smoking cessation and a 20-h/wk increase in television watching were associated with a 1.98-cm and 0.59-cm waist gain, respectively (P < 0.001). Increases of 25 metabolic equivalent tasks (METs) * h/wk in vigorous physical activity and of >/= 0.5 h/wk in weight training were associated with 0.38-cm and 0.91-cm decreases in waist circumference, respectively (P < 0.001 for each comparison). These associations remained significant after further adjustment for concurrent change in body mass index. Changes in total fat and alcohol consumption and in walking volume were not significantly related to waist gain.

CONCLUSIONS

Waist gain may be modulated by changes in trans fat and fiber consumption, smoking cessation, and physical activity.

Variations in body composition and plasma lipids in response to a high-carbohydrate diet

OBJECTIVE

To examine the extent to which variations in body composition modulate changes in the lipid profile in response to the ad libitum consumption of a diet rich in carbohydrates (CHOs) (high-CHO diet: 58% of energy as CHOs) or high in fat and in monounsaturated fatty acids (MUFAs) (high-MUFA diet: 40% of energy as fat, 23% as MUFAs).

RESEARCH METHODS AND PROCEDURES

Sixty-three men were randomly assigned to one of the two diets that they consumed for 6 to 7 weeks. Body composition and fasting plasma lipid levels were measured at the beginning and the end of the dietary intervention.

RESULTS

The high-CHO and high-MUFA diets induced significant and comparable reductions in body weight and waist circumference. These changes were accompanied by significant and comparable (p < 0.01) reductions in total plasma cholesterol and low-density lipoprotein cholesterol levels. However, the high-MUFA diet had more beneficial effects on plasma triglyceride concentrations (p < 0.01) and on plasma high-density lipoprotein cholesterol levels (p = 0.02) compared with the high-CHO diet. Diet-induced changes in waist circumference were significantly associated with changes in low-density lipoprotein cholesterol levels in the high-CHO group (r = 0.39, p = 0.03) but not in the high-MUFA group (r = 0.16, p = 0.38).

DISCUSSION

Improvements in plasma lipids induced by the ad libitum consumption of a high-CHO diet seem to be partly mediated by changes in body weight, whereas lipid changes induced by the high-MUFA diet seem to be independent of changes in body weight.

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.

A novel soy-based meal replacement formula for weight loss among obese individuals: a randomized controlled clinical trial

OBJECTIVE

To assess the efficacy and safety of a low calorie soy-based meal replacement program for the treatment of obesity.

DESIGN

A 12-week prospective randomized controlled clinical trial.

SETTING

Outpatient weight control research unit.

SUBJECTS

One hundred obese (28

INTERVENTION

Participants were randomized to either the meal replacement treatment group (n=50; 240 g/day, 1200 kcal/day) or control group (n=50). Both groups at baseline received a single dietary counseling session and a pamphlet describing weight loss practices.

MAIN OUTCOME MEASURES

Weight, body fat, serum lipid concentrations.

RESULTS

: By intent-to-treat analysis, the treatment group lost significantly more weight than the control group (7.00 vs 2.90 kg; P<0.001) and had a greater change in total (22.5 vs 6.8 mg/dl; P=0.013) and LDL cholesterol (21.2 vs 7.1 mg/dl; P<0.009). Among completers only, the treatment group again lost more weight (7.1 kg; n=37 vs 2.9 kg; n=37; P=0.0001) and had a greater reduction in total cholesterol (26.1 mg/dl; n=37 vs 6.7 mg/dl; P=0.0012) and a greater change in LDL cholesterol (21.6 vs 5.5 mg/dl; P=0.0025). (For any given degree of weight loss, the reduction in LDL cholesterol was significantly greater in the treatment group.) Treatment was well tolerated and no serious side effects were detected.

CONCLUSIONS

Use of this soy-based meal replacement formula was effective in lowering body weight, fat mass and in reducing LDL cholesterol beyond what could be expected given the weight lost.

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Key Words Collapse

MESH Headings

• Adult
• Blood Pressure
• Body Constitution
• Cholesterol/blood
• Cholesterol, HDL/blood
• Cholesterol, LDL/blood
• Dietary Fiber/administration & dosage
• Energy Intake
• Female
• Food, Formulated/adverse effects
• Humans
• Male
• Middle Aged
• Obesity/diet therapy
• Obesity/physiopathology
• Soybean Proteins/administration & dosage
• Glycine max
• Weight Loss

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Grants Collapse

Affiliation(s)

D B Allison Department of Biostatistics and Center for Research on Clinical Nutrition, University of Alabama at Birmingham, Birmingham, Alabama 35294-0022, USA
G Gadbury
L G Schwartz
R Murugesan
J L Kraker
S Heshka
K R Fontaine
S B Heymsfield

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