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1.
B S Reddy 《CMAJ》1980,123(9):850-856
Epidemiologic studies have identified two dietary factors, a relatively high intake of fat and a relatively low intake of fibre, that are associated with colon cancer in humans. However, a recent study has shown a low risk of large bowel cancer in a rural Finnish population with a high dietary intake of fat, but also a high intake of fibre. Observations in humans and studies in animals have indicated that dietary fibre may protect against colon carcinogenesis by binding bile acids in the intestinal tract, by a direct effect on the colonic mucosa and by an indirect effect on the metabolism of carcinogens. The strength of protection varies with the type of fibre.  相似文献   

2.
We previously reported differences in protein and carbohydrate selection patterns in post-weanling rats fed beef tallow or soybean oil-based diets. Two experiments were designed to determine the characteristic of the dietary fat which mediates the selection behavior. For each experiment, dietary fat was 20% (w/w) of diets and fatty acid profiles were obtained by blending fat sources. Rats were randomly assigned to diets (24% protein, 40% carbohydrate) which varied only in fatty acid composition. After 2 weeks, rats selected from 2 diets with the fat composition previously fed, but varying in their protein and carbohydrate composition (55% protein, 4% carbohydrate and 5% protein, 61% carbohydrate). Experiment 1 was designed to test the effect of relative (omega 6: omega 3 ratios of 1 and 20) and absolute (15% or 4% omega 6, 0.7% or 0.2% omega 3) differences in essential fatty acids on macronutrient selection patterns. Differences in dietary essential fatty acids had no effect on energy intake or the proportion of energy consumed as protein and carbohydrate. Experiment 2 examined the effect of differences in the level of saturated fat (3-10% diet (w/w] on protein and carbohydrate selection. Animals selecting from diets with higher levels of saturated fat consumed more energy as protein and less as carbohydrate than rats selecting from diets with lower levels of saturated fat (p less than 0.0001). Regression analysis was used to examine the relationship between percent protein or carbohydrate energy and classes of dietary fat. The strongest relationship existed between percent dietary saturated fat and percent protein or carbohydrate energy (p less than 0.0001). Polyunsaturated:saturated fat ratio was also weakly associated with percent protein and carbohydrate energy (p less than 0.05). Polyunsaturated, monounsaturated, omega 6 and omega 3 fatty acids were not significantly related to percent protein or carbohydrate energy. These results indicated that protein and carbohydrate selection patterns are altered in response to qualitatively different dietary fatty acids, and that the amount of saturated fat in the diet is the important characteristic of dietary fat mediating the behavioral alteration.  相似文献   

3.
The aims of this study were to determine medical students' knowledge regarding the association between dietary factors and the risk of cancer and cardiovascular diseases and to investigate if this knowledge has an impact on their dietary intakes. Three hundred and ninety medical students (males and females) were included in a study and grouped according to their daily fibre and fat intakes. For diet-disease knowledge, questions from the General Nutrition Knowledge Questionnaire for Adults were used and dietary assessment was done with Food Frequency Questionnaire. The obtained results showed that the students' diet-disease knowledge was generally inadequate. Higher level of diet-disease knowledge was among those with high dietary fibre intake, with slightly better scores for dietary factors and risk for cardiovascular diseases than the risk for cancer. Better diet-disease knowledge positively correlated with higher intake of fish (p = 0.027, p = 0.001) and vegetables (p = 0.019, p = 0.001) in high fibre groups of both gender, and in females additionally with fruit intake (p = 0.038, p = 0.007). A higher dietary fibre intake among studied students seems to be a factor that ensures lower obesity rates, lower intake of energy and lower consumption of coffee, sweets and alcoholic drinks. On the basis of the results of this study, it is clear that medical schools should provide in their nutrition programs the opportunity for students to learn about their own dietary and lifestyle behaviours, in order to more knowledgably and convincingly counsel their future patients.  相似文献   

4.
Ninety-four volunteers participated in a three-day weighed dietary survey and had their blood pressures measured once. They were classified according to their fibre intake. Subjects with a high-fibre intake were found to have lower mean blood pressures than those with a low-fibre intake. Forty-two of the volunteers further participated in a group of experiments. Those eating a high-fibre diet decreased their dietary fibre, and those eating a low-fibre diet increased their dietary fibre. The first group (11 subjects) showed increased mean blood pressures after four weeks of eating the experimental diet. The last group (31 subjects) showed decreased mean blood pressures after four weeks of eating the experimental diet. The 11 subjects consuming the low-fibre experimental diet showed a decrease in mean blood pressure when some of the saturated fat in their diet was replaced by polyunsaturated fat. A similar substitution carried out by 14 of the subjects consuming the high-fibre experimental diet also resulted in decreased mean blood pressure, but this was not statistically significant. Twelve more volunteers, with hypertension, were all found to have low-fibre diets. They consumed a high-fibre diet for a six-week experimental period, but their mean blood pressures did not decrease significantly; individual recordings varied substantially during this period.It is suggested that differences in the type and quantity of dietary fibre and fat may be responsible for the lower mean blood pressures of groups of vegetarians compared with similar groups of non-vegetarians.  相似文献   

5.
One hundred and sixty eight subjects participated in a randomised crossover study to determine whether halving or doubling the present dietary cholesterol intake from eggs had any influence on blood cholesterol concentration in people following current dietary recommendations. During the first eight weeks all participants were advised to follow a reduced fat diet (26% total energy for hyperlipidaemic patients, 35% total energy for normolipidaemic volunteers) with an increased ratio of polyunsaturated to saturated fatty acids. This background diet was continued throughout the 16 week experimental period, during which participants ate either two or seven eggs a week. A small but significant increase in total cholesterol was seen after four weeks in the group eating seven eggs a week compared with that in the group eating two eggs a week, but this was no longer apparent after eight weeks. Previous studies suggesting that dietary cholesterol has a greater effect on the serum cholesterol concentration either have been carried out against a background of a higher fat intake or have contrasted extreme cholesterol intakes. A further reduction in dietary cholesterol seems to be unnecessary in those people who have already reduced their intake of saturated fat and increased the ratio of polyunsaturated to saturated fatty acids and fibre rich carbohydrate.  相似文献   

6.
There is an intimate relationship between nutritional intake (eating) and serotonin activity. Experimental manipulations (mainly neuropharmacological) of serotonin influence the pattern of eating behavior, subjective feelings of appetite motivation, and the response to nutritional challenges. Similarly, nutritional manipulations (food restriction, dieting, or altered nutrient supply) change the sensitivity of the serotonin network. Traditionally, serotonin has been linked to the macronutrient carbohydrate via the intermediary step of plasma amino acid ratios. However, it has also been demonstrated that 5-HT drugs will reduce energy intake and reverse body weight gain in rats exposed to weight increasing high fat diets. 5-HT drugs can also reduce food intake and block weight gain of rats on a high fat cafeteria diet. Some diet selection studies in rats indicate that the most prominent reduction of macronutrient intake is for fat. These data indicate that 5-HT activity can bring about a reduction in fat consumption. In turn, different types of dietary fat can alter brain 5-HT activity. In human studies the methodology of food choice experiments has often precluded the detection of an effect of 5-HT manipulation on fat intake. However, there is evidence that in obese and lean subjects some 5-HT drugs can readily reduce the intake of high fat foods. Data also suggest that 5-HT activation can lead to a selective avoidance of fat in the diet. These effects of 5-HT on the intake of dietary fat may involve a pre-absorptive mechanism and there is evidence that 5-HT is linked to cholecystokinin and enterostatin. These proposals have theoretical and practical implications and suggest possible strategies to intensify or advance fat-induced satiety signals.  相似文献   

7.
Insulin and glucagon receptors were measured on hepatocytes in relation to circulating hormones (insulin, glucagon and growth hormone) and metabolites (non-esterified fatty acids, volatile fatty acids, glucose, total lipids, urea and alpha-amino nitrogen), in twelve, two-year old, castrated male goats, fed rations of different composition and dietary energy. The goats were separated into four groups; group 1 was fed a restricted ration of 600 g clover hay/day, group 2 a ration high in carbohydrate (rolled barley), group 3 a ration high in fat (protected tallow) and group 4 a ration high in protein (fish meal). Rations in groups 2 - 4 were fed at 1300 g/day supplemented with 600 g of clover hay. The binding of insulin to hepatocyte receptors was increased by restricting dietary intake when compared to the high energy intake groups (p less than 0.01). There was no significant difference between the insulin binding of groups 2 -4. Glucagon receptor binding was increased on the high protein diet in comparison with th ration high in carbohydrate (p less than 0.05) or in fat (p less than 0.01). The glucagon binding was reduced by restricting feed intake when compared wih feeding high protein (p less than 0.02), but slightly increased when compared with feeding diets high in both carbohydrate or fat (p less than 0.02). There was no significant difference between the high carbohydrate or high fat fed groups. These changes in hormone receptors were accompanied by inverse changes in plasma insulin and glucagon.  相似文献   

8.
OBJECTIVE--To compare high fibre diet, basal insulin supplements and a regimen of insulin four times daily in non-insulin dependent (type II) diabetic patients who were poorly controlled with sulphonylureas. DESIGN--Run in period lasting 2-3 months during which self monitoring of glucose concentration was taught, followed by six months on a high fibre diet, followed by six months'' treatment with insulin in those patients who did not respond to the high fibre diet. SETTING--Teaching hospital diabetic clinics. PATIENTS--33 patients who had had diabetes for at least two years and had haemoglobin A1 concentrations over 10% despite receiving nearly maximum doses of oral hypoglycaemic agents. No absolute indications for treatment with insulin. INTERVENTIONS--During the high fibre diet daily fibre intake was increased by a mean of 16 g (95% confidence interval 12 to 20 g.) Twenty five patients were then started on once daily insulin. After three months 14 patients were started on four injections of insulin daily. ENDPOINT--Control of diabetes (haemoglobin A1 concentration less than or equal to 10% and fasting plasma glucose concentration less than or equal to 6 mmol/l) or completion of six months on insulin treatment. MEASUREMENTS AND MAIN RESULTS-- No change in weight, diet, or concentrations of fasting glucose or haemoglobin A1 occurred during run in period. During high fibre diet there were no changes in haemoglobin A1 concentrations, but mean fasting glucose concentrations rose by 1.7 mmol/l (95% confidence interval 0.9 to 2.5, p less than 0.01). With once daily insulin mean concentrations of fasting plasma glucose fell from 12.6 to 7.6 mmol/l (p less than 0.001) and haemoglobin A1 from 14.6% to 11.2% (p less than 0.001). With insulin four times daily concentrations of haemoglobin A1 fell from 11.5% to 9.6% (p less than 0.02). Lipid concentrations were unchanged by high fibre diet. In patients receiving insulin the mean cholesterol concentrations fell from 7.1 to 6.4 mmol/l (p less than 0.0001), high density lipoprotein concentrations rose from 1.1 to 1.29 mmol/l (p less than 0.01), and triglyceride concentrations fell from 2.67 to 1.86 mmol/l (p less than 0.05). Patients taking insulin gained weight and those taking it four times daily gained an average of 4.2 kg. CONCLUSIONS--High fibre diets worsen control of diabetes in patients who are poorly controlled with oral hypoglycaemic agents. Maximum improvements in control of diabetes were achieved by taking insulin four times daily.  相似文献   

9.
The incretin hormone glucagon‐like peptide‐1 (GLP‐1) has been implicated in the regulation of appetite by acting as an anorexigenic gut‐brain signal. The postprandial release of GLP‐1 can be blunted in obese humans and animals. However, it remains unknown whether obesogenic diets with varying fat and carbohydrate content may differentially influence the effectiveness of GLP‐1 feedback. To investigate this, male Sprague‐Dawley rats were fed a standard (low fat) chow diet, or one of two high‐energy diets varying in fat content (45 or 60 kcal%) for 28 weeks. Intake of sucrose and fructose solutions, two commonly added sugars in the Western diet, was then tested in nondeprived rats following administration of the GLP‐1 receptor agonist, Exendin‐4 (0, 0.5, 1, 2, 3 µg/kg; s.c.). Exendin‐4 dose‐dependently reduced short (2 h) sucrose and fructose intake. This effect was significantly attenuated in rats fed more dietary fat, despite both diets resulting in obesity. These findings demonstrate that intake of carbohydrates when offered as treats can be regulated by GLP‐1 and suggests that dietary fat consumption, rather than extra calories or obesity, may lead to impaired GLP‐1 feedback to curb carbohydrate intake. Future studies are warranted to investigate the relevance of these observations to humans and to elucidate the underlying mechanisms.  相似文献   

10.
Quantifying eating behavior may give clues to both the physiological and behavioral mechanisms behind weight regulation. We analyzed year-long dietary records of 29 stable-weight subjects. The records showed wide daily variations of food intake. We computed the temporal autocorrelation and skewness of food intake mass, energy, carbohydrate, fat, and protein. We also computed the cross-correlation coefficient between intake mass and intake energy. The mass of the food intake exhibited long-term trends that were positively skewed, with wide variability among individuals. The average duration of the trends (P = 0.003) and the skewness (P = 0.006) of the food intake mass were significantly correlated with mean body mass index (BMI). We also found that the lower the correlation coefficient between the energy content and the mass of food intake, the higher the BMI. Our results imply that humans in neutral energy balance eating ad libitum exhibit a long-term positive bias in the food intake that operates partially through the mass of food eaten to defend against eating too little more vigorously than eating too much.  相似文献   

11.
Objective: To ascertain the relationship between dietary fibre intake and risk of oesophageal cancer in remote northwest China, where the cancer incidence is known to be high. Methods: A case–control study was conducted during 2008–2009 in the Urumqi and Shihezi, Xinjiang Uyghur Autonomous Region of China. Participants were 359 incident oesophageal cancer patients and 380 hospital-based controls. Information on habitual foods consumption was obtained by face-to-face interview, from which dietary fibre intakes were estimated using the Chinese food composition tables. Results: The oesophageal cancer patients reported lower intake levels of total dietary fibre and fibre derived from vegetables and fruits than those of controls. Overall, regular intake of fibre was inversely associated with the oesophageal cancer risk, the adjusted odds ratio being 0.47 (95% confidence interval 0.32–0.69) for the highest (>27 g) versus the lowest (<16 g) tertile of daily intake, with a significant dose-response relationship (p = 0.004). Similar reductions in risk were also apparent for high intake levels of vegetable fibre and fruit fibre, but to a lesser extent for cereal fibre. Conclusion: Habitual intake of dietary fibre was associated with a reduced risk of oesophageal cancer for adults in northwest China.  相似文献   

12.
The dietary management of childhood diabetes is complex. Is it possible to educate young people to balance carbohydrate with their insulin? Can dietary knowledge be translated into lasting behaviour change? Do present teaching methods provide the skills necessary for children and parents to adjust their insulin therapy adequately? Evidence shows great variation in glycaemic control between centres and countries but the impact of dietary education methods is poorly evaluated and its links with clinical and psychosocial outcomes is virtually unknown. There is also little evidence to suggest cohesive teamworking with clear dietary targets for glycaemic control, lipids, incidence of hypoglycaemia, compliance, effect on peer and sibling relationships, and evaluation of individual dietary components, e.g. fibre, fat, antioxidants. There is wide variation in methods of dietary education, which are often based on historic practice. They include rigid counting of grams of carbohydrate, carbohydrate portion assessments, qualitative diets, low glycaemic index diets and the more recent 'intensified' carbohydrate measures with daily adjustments of insulin (the basis also of pump management). This last method has many benefits although it requires extensive nutrition education, it allows greater flexibility and variety of food intake, is sensitive to the varying daily energy expenditure of childhood and it addresses postprandial glycaemic excursions, all of which are inadequately managed by conventional therapy. However, one of the problems of overemphasizing carbohydrate measurement is that total carbohydrate intake may be suppressed, with a resulting increase in fat, this may contribute to an increase in cardiovascular risk. The ISPAD Consensus Guidelines 2000 contain dietary recommendations but scientific evidence is often lacking. Limited dietary studies show that some countries can meet guidelines more successfully than others. There are many reasons for this, such as food availability, types of food eaten, food preferences and family/cultural/religious influences. Educational methods must be adapted to local customs. Is there enough evidence to recommend a particular dietary education method? What outcomes do we hope to achieve? The workshop explored these issues in order to develop a deeper understanding of the complexity of dietary modification in childhood diabetes.  相似文献   

13.
The purpose of the current study was to examine the effects of a very low-carbohydrate diet on weight loss and biochemical parameters in overweight women. Twenty women completed an 8-week trial that reduced their daily carbohydrate intake from 232 to 71 g (p < 0.05) and reduced energy by 2,644 kJ/day (8,384 to 5,740 kJ, p < 0.001). The average weight loss was 5.0 kg (p < 0.0001), with a net decrease in body mass index of 1.82 kg/m2, a loss of 3.4% body fat (4 kg, p < 0.0001), and a loss of 1.0 kg lean mass (p < 0.05). There were no significant changes in fasting blood glucose, fasting serum insulin, oral glucose tolerance, free or total insulin-like growth factor-1, or total IGFBP-3. Systolicblood pressure decreased by an average of 9.0 mmHg (1 mmHg = 133.322 Pa) (p < 0.01) and diastolic blood pressure decreased by 7 mmHg (p < 0.05). Total cholesterol decreased 1.2 mM (p < 0.001), all of which was accounted for by a decrease in low-density lipoprotein cholesterol (p < 0.001) with no change in high-density lipoprotein cholesterol (baseline, 1.17 mM; week 8, 1.22 mM). Total triacylglycerol decreased 0.6 mM (p < 0.01), and the ratio of triacylglycerol/HDL also significantly decreased (baseline, 1.40; week 8, 0.87; p < 0.001). Serum beta-hydroxybutyrate concentrations rose significantly by week 2 and declined thereafter but remained significantly higher than baseline values for the duration of the intervention. Therefore, carbohydrate restriction to 70 g or less with concomitant energy restriction, without changes in protein or fat consumption, promotes weight loss, and improvements in body composition, blood pressure, and blood lipids without compromising glucose tolerance in moderately overweight women.  相似文献   

14.
Food intake rate has previously been derived from observation of eating behavior in laboratory settings or in public eating establishments. Although it has been suggested that obese individuals eat faster than lean individuals, observations of such an “obese eating style” have yielded mixed results. In the present study, the relationship between ad-libitum food intake rate and obesity was evaluated over 4 days on a metabolic ward in 28 healthy Pima Indian men (Mean ± SD; 29 ± 7 y, 100.4 ± 27.1 kg, 33 ± 10% body fat) using an automated food selection system containing a large variety of foods . Total energy intake averaged 18829 ± 3299 kJ/d consisting of 47 ± 4,40 ± 3, and 13 ± 1 percent of carbohydrate, fat and protein, respectively. The average meal duration was 25 ± 7 min. Food intake rate was 68 ± 21 g/min while carbohydrate, fat and protein intake rates were 23 ± 6, 9 ± 3 and 6 ± 2 g/min, respectively. Food intake rate correlated negatively with %body fat (1=0.61, P<0.01). Similar relationships were found between the intake rates of carbohydrate, fat and protein and body fatness. Only prospective studies will indicate whether a slow food intake rate may contribute to the etiology of obesity by possibly reducing satiety .  相似文献   

15.
ObjectivesTo examine the relation between self reported eating frequency and serum lipid concentrations in a free living population.Design Cross sectional population based study.Setting Norfolk, England.Participants 14 666 men and women aged 45-75 years from the Norfolk cohort of the European prospective investigation into cancer (EPIC-Norfolk).Results Mean concentrations of total cholesterol and low density lipoprotein cholesterol decreased in a continuous relation with increasing daily frequency of eating in men and women. No consistent relation was observed for high density lipoprotein cholesterol, body mass index, waist to hip ratio, or blood pressure. Mean cholesterol concentrations differed by about 0.25 mmol/l between people eating more than six times a day and those eating once or twice daily; this difference was reduced to 0.15 mmol/l after adjustment for possible confounding variables, including age, obesity, cigarette smoking, physical activity, and intake of energy and nutrients (alcohol, fat, fatty acids, protein, and carbohydrate).Conclusions Concentrations of total cholesterol and low density lipoprotein cholesterol are negatively and consistently associated with frequency of eating in a general population. The effects of eating frequency on lipid concentrations induced in short term trials in animals and human volunteers under controlled laboratory conditions can be observed in a free living general population. We need to consider not just what we eat but how often we eat.

What is already known on this topic

Studies in animals and small human trials indicate that eating frequency is inversely related to serum lipid concentrationsFew studies have examined this in a free living population under no dietary restrictions

What this study adds

In a free living population increased eating frequency was negatively and significantly associated with concentrations of total cholesterol and low density lipoprotein cholesterolThis association was still present after adjustment for body mass index, physical activity, cigarette smoking, and dietary intakeMean age adjusted cholesterol concentrations differed by 0.25 mmol/l between people eating more than six times a day and those eating less than twice daily  相似文献   

16.
The effect of storage on carbohydrate composition of three redgram (TTB-7, BRG-1 and ICP-8863) and three greengram (Pusa Bisaki, KDM-1 and China Moong) varieties during storage was studied. The total free sugars, starch and dietary fibre were evaluated both in control and in samples stored for six months. Decrease in percentage of (a) free non-reducing sugars, (b) starch and (c) pentose sugar of dietary fibre was observed during storage. Concomitantly insect infested samples showed increase in reducing sugar, dietary fibre and also hexose sugars of dietary fibre.  相似文献   

17.
Objective: To characterize the dose‐response relationship between dietary fat to carbohydrate ratio and spontaneous caloric intake. Research Methods and Procedures: Male Long‐Evans rats consumed milk‐based liquid diets that differed in fat content (17% to 60% of kilocalories) but had equivalent protein content and energy density. In Experiment 1, rats consumed one of the diets (n = 9/diet group) as the sole source of nutrition for 16 days. In Experiment 2, diets were offered as an option to nutritionally complete chow for 4 days followed by a 3‐day chow‐only washout in a randomized within‐subjects design (n = 30). In Experiment 3, nine rats received isocaloric intragastric infusions of diet overnight, with chow available ad libitum. At least two no‐infusion days separated the different diet infusions, which were given in random order. Food intake was measured daily Results: Dietary fat dose dependently increased total daily kilocalories in each of the three paradigms. Discussion: These data imply that the postingestive effects of carbohydrate and fat differentially engage the physiological substrates that regulate daily caloric intake. These findings reiterate the importance of investigating macronutrient‐specific controls of feeding, rather than prematurely concluding that dietary attributes that covary with fat content (e.g., caloric density and palatability) drive the overeating associated with a high‐fat diet.  相似文献   

18.
We have compared, using non protein RQ method, energy expenditures of diarrheic patients with intraperitoneal or intraluminal suppuration and feed enterally (group II) or intravenously (group III). Five non suppurative diarrheic patients feed enterally were studied as control (group I). Carbohydrate, protein and fat intakes were not significantly different in the 3 groups of patients. Patients of group II metabolized significantly less of carbohydrate (p less than 0.01) and more of fat (P less than 0.01) than groups I and III patients. Carbohydrate and fat expenditures of patients of groups I and III were not significantly different. Conclusion: 1) There is a possible trouble of carbohydrate absorption in suppurative diarrheic patients. 2) Therefore caloric intake must be preferably parenteral in these patients.  相似文献   

19.
Members of the genus Simonsiella, aerobic, multicellular filamentous gliding bacteria, were detected in swabbings from the palates of 32% of 212 human subjects free of gross oral pathologies. Nutritional evaluations for 142 of the subjects showed a significantly greater daily intake among 53 Simonsiella carriers for 13 dietary variables, including four fat components, but there was no significantly greater daily intake for any of the carbohydrate components. Overall, there was a general excess dietary intake by Simonsiella carriers. The mean dietary intake of the carriers was numerically greater than that of the noncarriers for 70 of 74 dietary variables.  相似文献   

20.
Members of the genus Simonsiella, aerobic, multicellular filamentous gliding bacteria, were detected in swabbings from the palates of 32% of 212 human subjects free of gross oral pathologies. Nutritional evaluations for 142 of the subjects showed a significantly greater daily intake among 53 Simonsiella carriers for 13 dietary variables, including four fat components, but there was no significantly greater daily intake for any of the carbohydrate components. Overall, there was a general excess dietary intake by Simonsiella carriers. The mean dietary intake of the carriers was numerically greater than that of the noncarriers for 70 of 74 dietary variables.  相似文献   

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