Glycaemic index database for the epidemiological Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study

Interest in the dietary glycaemic index (GI) and glycaemic load (GL) as risk factors for chronic diseases has grown in recent years but findings have been controversial. We describe the compilation of the GI database for the cohort studies within the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study and the main characteristics associating with diet GI and GL. The ATBC Study enrolled 29 133 male smokers aged 50-69 years who filled in a dietary history questionnaire upon study entry. The dietary data included 1097 foods, of which 195 foods with no or a negligible amount of available carbohydrates were assigned a GI of zero. Based on preset methodological criteria for published GI studies, the GI value of a similar food was available for 130 foods, and the GI of related food was assigned to 360 foods. The GI values of these foods served in the GI calculation of 412 composite foods. The median diet GI among the ATBC Study participants was 67.3 (interquartile range 64.8-70.0), and the median diet GL was 175 (interquartile range 158-192). The intakes of carbohydrates, protein and fat decreased, and the intake of fibre increased, with increasing GI. The GL showed a positive correlation with intakes of carbohydrates and dietary fibre and a negative correlation with intakes of protein and fat. The GI studies available that fulfilled the minimum methodological requirements cover a sufficient amount of foods to form a meaningful GI database for epidemiological study. This, however, requires the availability of GI values for relevant local carbohydrate-containing foods.     

Association between dietary carbohydrate,glycemic index,glycemic load,and the prevalence of obesity in Korean men and women

Intake of high–glycemic index (GI) food has been postulated to reduce satiety, resulting in an increased total energy intake and reduced access to body fat as fuel. Thus, we hypothesize that high dietary GI and glycemic load (GL) are associated with an increased prevalence of obesity in the Korean population. Dietary GI and GL were calculated for 933 Korean men and women based on dietary intake assessed by food frequency questionnaires and using a GI table developed from published GI databases in a cross-sectional design. Mean differences in dietary GL and carbohydrate intake between obese and nonobese men were statistically significant after adjusting for covariates (P = .027 and .021, respectively). High dietary GL and carbohydrate intake were negatively associated with the prevalence of obesity among men in a multivariate-adjusted logistic regression model (P for trend = .026 and .036, respectively). Statistically significant effects of dietary GI and GL on the prevalence of obesity among women were observed in a generalized linear model (P = .002 and .042, respectively) and a logistic regression model (P for trend < .001 and = .007, respectively), after adjusting for covariates. Women with higher dietary GI and GL were more likely to be obese, a result consistent with our hypothesis. However, an inverse association for dietary GL and carbohydrate and prevalence of obesity was found in men, suggesting that mechanisms contributing to the prevalence of obesity between sexes may be different.     

Adding glycaemic index and glycaemic load functionality to DietPLUS, a Malaysian food composition database and diet intake calculator

This paper outlines the methodology to add glycaemic index (GI) and glycaemic load (GL) functionality to food DietPLUS, a Microsoft Excel-based Malaysian food composition database and diet intake calculator. Locally determined GI values and published international GI databases were used as the source of GI values. Previously published methodology for GI value assignment was modified to add GI and GL calculators to the database. Two popular local low GI foods were added to the DietPLUS database, bringing up the total number of foods in the database to 838 foods. Overall, in relation to the 539 major carbohydrate foods in the Malaysian Food Composition Database, 243 (45%) food items had local Malaysian values or were directly matched to International GI database and another 180 (33%) of the foods were linked to closely-related foods in the GI databases used. The mean ± SD dietary GI and GL of the dietary intake of 63 women with previous gestational diabetes mellitus, calculated using DietPLUS version3 were, 62 ± 6 and 142 ± 45, respectively. These values were comparable to those reported from other local studies. DietPLUS version3, a simple Microsoft Excel-based programme aids calculation of diet GI and GL for Malaysian diets based on food records.     

Dietary glycaemic index and glycaemic load among Australian children and adolescents

There are no published data regarding the overall dietary glycaemic index (GI) and glycaemic load (GL) of Australian children and adolescents. We therefore aim to describe the dietary GI and GL of participants of the 2007 Australian National Children's Nutrition and Physical Activity Survey (2007ANCNPAS), and to identify the main foods contributing to their GL. Children, aged 2-16 years, who provided two 24 h recalls in the 2007ANCNPAS were included. A final dataset of 4184 participants was analysed. GI of each food item was assigned using a previously published method. GL was calculated, and food groups contributing to the GL were described by age group and sex. The weighted mean dietary GI and GL of the participants were 54 (SD 5) and 136 (SD 44), respectively. Among the nutrients examined, Ca had the highest inverse relationship with GI (P < 0·001), while percentage energy from starch was most positively associated with GI. The association between fibre density and GI was modest, and percentage energy from sugar had an inverse relationship with GI. Daily dietary GL contributed by energy-dense and/or nutrient-poor (EDNP) items in subjects aged 14-16 years was more than doubled that of subjects aged 2-3 years. To conclude, Australian children and adolescents were having a high-GI dietary pattern characterised by high-starchy food intake and low Ca intake. A significant proportion of their dietary GL was from EDNP foods. Efforts to reduce dietary GI and GL in children and adolescents should focus on energy-dense starchy foods.     

Low-, medium- and high-glycaemic index carbohydrates and risk of type 2 diabetes in men

Findings on dietary glycaemic index (GI) and glycaemic load (GL) as risk factors for type 2 diabetes have been controversial. We examined the associations of dietary GI and GL and the associations of substitution of lower-GI carbohydrates for higher-GI carbohydrates with diabetes risk in a cohort of Finnish men. The cohort consisted of 25?943 male smokers aged 50-69 years. Diet was assessed, at baseline, using a validated diet history questionnaire. During a 12-year follow-up, 1098 incident diabetes cases were identified from a national register. Cox proportional hazard modelling was used to estimate the risk of diabetes, and multivariate nutrient density models were used to examine the effects of substitution of different carbohydrates. Dietary GI and GL were not associated with diabetes risk; multivariate relative risk (RR) for highest v. lowest quintile for GI was 0·87 (95?% CI 0·71, 1·07) and for GL 0·88 (95?% CI 0·65, 1·17). Substitution of medium-GI carbohydrates for high-GI carbohydrates was inversely associated with diabetes risk (multivariate RR for highest v. lowest quintile 0·75, 95?% CI 0·59, 0·96), but substitution of low-GI carbohydrates for medium- or high-GI carbohydrates was not associated with the risk. In conclusion, dietary GI and GL were not associated with diabetes risk, and substitutions of lower-GI carbohydrates for higher-GI carbohydrates were not consistently associated with a lower diabetes risk. The associations of dietary GI and GL with diabetes risk should be interpreted by considering nutritional correlates, as foods may have different properties that affect risk.     

Glycemic index and glycemic load in relation to food and nutrient intake and metabolic risk factors in a Dutch population

BACKGROUND: Previous studies on the glycemic index (GI) and glycemic load (GL) reported inconsistent findings on their association with metabolic risk factors. This may partly have been due to differences in underlying dietary patterns. OBJECTIVE: We aimed to examine the association of GI and GL with food and nutrient intake and with metabolic risk factors including blood glucose, insulin, lipids, and high-sensitivity C-reactive protein (CRP). DESIGN: The study entailed cross-sectional analyses of data from 2 joint observational studies, the CoDAM Study and the Hoorn Study. RESULTS: In total, 974 subjects aged 42-87 y were included in the study. The mean (+/-SD) GI was 57 +/- 4 and the mean GL was 130 +/- 39. Dairy products, potatoes and other tubers, cereal products, and fruit were the main predictive food groups for GI. GL was closely correlated with intake of total carbohydrates (r(s) = 0.97), which explained >95% of the variation in GL. After adjustment for potential confounders, GI was significantly inversely associated with HDL cholesterol and positively associated with fasting insulin, the homeostasis model assessment index of insulin resistance, the ratio of total to HDL cholesterol, and CRP. No association was observed between GL and any of the metabolic risk factors, except for a borderline significant positive association with CRP. CONCLUSIONS: In this population, a low-GI diet, which is high in dairy and fruit but low in potatoes and cereals, is associated with improved insulin sensitivity and lipid metabolism and reduced chronic inflammation. GL is highly correlated with carbohydrate intake and is not clearly associated with the investigated metabolic risk factors.     

Glycemic load, glycemic index, and pancreatic cancer risk in the Netherlands Cohort Study

BACKGROUND: Recent studies of pancreatic cancer suggest a role for hyperinsulinemia in carcinogenesis. Because insulin is secreted in response to elevated blood glucose concentrations, dietary factors that increase these concentrations may be important in pancreatic carcinogenesis. OBJECTIVE: The objective was to examine prospectively the relation between pancreatic cancer risk and dietary glycemic load (GL), overall glycemic index (GI), and intake of total carbohydrates and mono- and disaccharides. DESIGN: The Netherlands Cohort Study consisted of 120,852 men and women who completed a baseline questionnaire in 1986. After 13.3 y of follow-up, 408 pancreatic cancer cases were detected, 66% of which were microscopically confirmed. A validated 150-item food-frequency questionnaire, completed at baseline, was used to calculate carbohydrate and mono- and disaccharide intakes and the GL and GI of the diet. RESULTS: Dietary GL, GI, or intake of carbohydrates and mono- and disaccharides were not associated with pancreatic cancer risk in this cohort. Also, the associations were not modified by sex. Our results did not change after the analysis was restricted to microscopically confirmed pancreatic cancer cases or after individuals who reported a history of diabetes at baseline were excluded from the analyses. CONCLUSIONS: Overall, our findings do not support the hypothesis that GL, GI, or intake of carbohydrates and mono- and disaccharides are positively associated with pancreatic cancer risk. This is in agreement with previous prospective studies that investigated the relation between GL and GI and pancreatic cancer risk.     

Methodology for Adding Glycemic Index to the National Health and Nutrition Examination Survey Nutrient Database

Generating valid estimates of dietary glycemic index (GI) and glycemic load (GL) has been a challenge in nutritional epidemiology. The methodologic issues may have contributed to the wide variation of GI/GL associations with health outcomes observed in existing literature. We describe a standardized methodology for assigning GI values to items in the National Health and Nutrition Examination Survey (NHANES) nutrient database using the new International Tables to develop research-driven, systematic procedures and strategies to estimate dietary GI/GL exposures of a nationally representative population sample. Nutrient databases for NHANES 2003-2006 contain information on 3,155 unique foods derived from the US Department of Agriculture National Nutrient Database for Standard Reference versions 18 and 20. Assignment of GI values were made to a subset of 2,078 carbohydrate-containing foods using systematic food item matching procedures applied to 2008 international GI tables and online data sources. Matching protocols indicated that 45.4% of foods had identical matches with existing data sources, 31.9% had similar matches, 2.5% derived GI values calculated with the formula for combination foods, 13.6% were assigned a default GI value based on low carbohydrate content, and 6.7% of GI values were based on data extrapolation. Most GI values were derived from international sources; 36.1% were from North American product information. To confirm data assignments, dietary GI and GL intakes of the NHANES 2003-2006 adult participants were estimated from two 24-hour recalls and compared with published studies. Among the 3,689 men and 4,112 women studied, mean dietary GI was 56.2 (men 56.9, women 55.5), mean dietary GL was 138.1 (men 162.1, women 116.4); the distribution of dietary GI was approximately normal. Estimates of population GI and GL compare favorably with other published literature. This methodology of adding GI values to an existing population nutrient database utilized systematic matching protocols and the latest comprehensive data sources on food composition. The database can be applied in clinical and survey research settings where there is interest in estimating individual and population dietary exposures and relating them to health outcomes.     

Dietary glycemic index and glycemic load among Indigenous and non-Indigenous children aged 10-12 years

ObjectiveThis study aimed to estimate the dietary glycemic index (GI) and glycemic load (GL) of Australian Aboriginal and Torres Strait Islander and non-Indigenous rural children and identify the main foods contributing to their GI and GL.MethodsA cross-sectional analysis of food intake of 215 children (38.1% were Aboriginal and Torres Strait Islanders) 10 to 12 y old obtained by three 24-h recalls was conducted. The foods were ranked according to their total contribution to total carbohydrates, GI, and GL.ResultsAboriginal and Torres Strait Islander participants had a significantly higher dietary GL (155.8 ± 46.8 versus 135.4 ± 31.2, P < 0.001) and GI (58.3 ± 3.9 versus 56.9 ± 3.8, P = 0.008) than the non-Indigenous participants. White breads were the main contributors of GI and GL in both groups and were a main driver for the increasing GI. Fiber was not associated with GI, whereas sugar and starch were positively associated. Subjects with a higher GI tended to be less physically active.ConclusionThe quality of carbohydrates in the diets of the participants was low, with poorer dietary items contributing most of the GI and GL. Substituting white breads with low/lower GI alternatives may be a useful strategy.     

Cross-sectional relationship between dietary carbohydrate, glycaemic index, glycaemic load and risk of the metabolic syndrome in a Korean population

Little is known about the effect of dietary carbohydrate, glycaemic index (GI) and glycaemic load (GL) on the risk of the metabolic syndrome, especially in populations with white rice as the staple food. The study examined the cross-sectional relationship between carbohydrate, GI, GL and risk of the metabolic syndrome. There were a total of 910 middle-aged Korean adults. Dietary carbohydrate, GI and GL were determined by an interview-administered FFQ. The metabolic syndrome was defined using the modified criteria published in the Third Report of the National Cholesterol Education Program Adult Treatment Panel III. The risk of developing the metabolic syndrome was positively related to dietary carbohydrate (P for trend = 0.03), GI (P for trend = 0.03) and GL intakes (P for trend = 0.02) in women after adjusting for potential confounding variables. Among the components of developing the metabolic syndrome, the risk of high TAG and low HDL-cholesterol were positively related to high GI and GL intakes in women. The risk of developing the metabolic syndrome was considerably higher in the highest quintiles of carbohydrate (OR 6.44; 95 % CI 2.16, 19.2), GI (OR 10.4; 95 % CI 3.24, 33.3) and GL intakes (OR 6.68; 95 % CI 2.30, 19.4) than in the lowest quintiles among women with a BMI >/= 25 kg/m2. However, there was no difference in risk across quintiles of carbohydrate, GI and GL among women with a BMI < 25 kg/m2. In conclusion, both the quantity and quality of carbohydrate intake has a positive relationship with the risk of the metabolic syndrome in women but this relationship was dependent on the BMI level.     

Dietary glycaemic index and glycaemic load in Danish children in relation to body fatness

The aim of this study was to describe dietary glycaemic index (GI) and glycaemic load (GL) values in the diets of Danish children, and to examine the associations between dietary GI, GL and body fatness. Data were collected during 1997-8 as part of the European Youth Heart Study. The study population comprised 485 children aged 10 years and 364 children aged 16 years from Odense County, Denmark. Dietary GI and GL were estimated using international food tables, and the associations between energy-adjusted dietary GI, GL and body fatness were analysed by multiple linear regression. The mean daily dietary GI value was 85 (SD 6.9) with a range of 62-111. No significant differences were found between age groups and gender. The daily dietary GL was higher among boys aged 16, with a GL of 330 (sd 95) (P<0.05), compared with girls or younger boys. Dietary GL was higher among 10-year-old boys than girls (250 (sd 81) v. 230 (sd 66) P<0.05), whereas dietary GL among 16-year-old girls was 230 (sd 56). Neither dietary GI nor GL was associated with the sum of four skinfolds (SigmaSF) among girls or among 10-year-old boys. Among 16-year-old boys, significant associations were observed between dietary GI and SigmaSF (beta=0.60, SE=0.21, P=0.006), and between dietary GL and SigmaSF (beta=0.15, SE=0.06, P=0.009). In conclusion, dietary GI and GL were positively associated with body fatness among Danish boys aged 16 years, whereas no associations were found among girls or younger boys.     

Dietary glycaemic load and intakes of carbohydrates, fats and proteins in 1040 hospitalised adult Chinese subjects

Metabolic diseases in China have been on the rise during recent decades. To investigate dietary glycaemic load (GL) and its correlation with the prevalence of metabolic diseases in hospitalised Chinese adults, we analysed the total energy and macronutrient intakes in 1040 patients. Dietary GL was calculated based upon glycaemic index (GI), carbohydrate content and daily intake of individual foods. Dietary patterns at different dietary GL levels and the distribution of dietary GL were analysed in patients from the internal medical departments v. those from surgical departments. Height and weight were measured using a standardised protocol. The present study results demonstrated that in hospitalised adults, 95·5?% of dietary GL came from cereals. Average GL was higher in male patients than in female patients, and was higher in patients from surgical departments than in patients from medical departments. Patients with lower dietary GL consumed inadequate carbohydrates and excessive fats, and therefore had a higher prevalence of overweight and obesity. Dietary GL analysis may be helpful to nutrition assessment and rational diet intervention in hospitalised Chinese patients.     

Cereal grains and legumes in the prevention of coronary heart disease and stroke: a review of the literature

A number of reviewers have examined studies investigating the relationship between coronary heart disease and stroke prior to 2000. Since then, several key studies have been published. Five studies have examined the relationship between wholegrain consumption, coronary heart disease (CHD) and cardiovascular (CVD) disease and found protection for either or both diseases. The researchers concluded that a relationship between wholegrain intake and CHD is seen with at least a 20% and perhaps a 40% reduction in risk for those who eat wholegrain food habitually vs those who eat them rarely. Notwithstanding the fact that fibre is an important component of wholegrains, many studies have not shown an independent effect of fibre alone on CHD events. Thus in terms of CHD prevention, fibre is best obtained from wholegrain sources. Wholegrain products have strong antioxidant activity and contain phytoestrogens, but there is insufficient evidence to determine whether this is beneficial in CHD prevention. Soluble fibre clearly lowers cholesterol to a small but significant degree and one would expect that this would reduce CHD events. There have been a small number of epidemiological studies showing soy consumption is associated with lower rates of heart disease. Countering the positive evidence for wholegrain and legume intake has been the Nurses Health Study in 2000 that showed women who were overweight or obese consuming a high glycaemic load (GL) diet doubled their relative risk of CHD compared with those consuming a low GL diet. Although the literature relating GL with CHD events is somewhat mixed, the relationship with risk factors such as HDL cholesterol, triglyceride and C reactive protein is relatively clear. Thus, carbohydrate-rich foods should be wholegrain and, if they are not, then the lowest glycaemic index (GI) product should be used. Promotion of carbohydrate foods should be focused on wholegrain cereals because these have proven to be associated with health benefits. There is insufficient evidence about whether the addition of other components of wholegrains such as polyphenolics or minerals (such as magnesium or zinc) would improve the health benefits of refined grain foods and this needs investigation. Whether adding bran to refined carbohydrate foods can improve the situation is also not clear, and it was found that added bran lowered heart disease risk in men by 30%. This persisted after full adjustment (including GL) suggesting, at least in men, that fibre may be more important than GI. Thus there are two messages: The intake of wholegrain foods clearly protects against heart disease and stroke but the exact mechanism is not clear. Fibre, magnesium, folate and vitamins B6 and vitamin E may be important.The intake of high GI carbohydrates (from both grain and non-grain sources) in large amounts is associated with an increased risk of heart disease in overweight and obese women even when fibre intake is high but this requires further confirmation in normal-weight women.Recommendation: Carbohydrate-rich foods should be wholegrain and if they are not, then the lowest GI product available should be consumed. Glycemic index is largely irrelevant for foods that contain small amounts of carbohydrate per serve (such as most vegetables).     

Dietary patterns based on carbohydrate nutrition are associated with the risk for diabetes and dyslipidemia

Several studies have been conducted on dietary patterns based on carbohydrate nutrition in Asian populations. We examined the cross-sectional associations in dietary patterns based on carbohydrate nutrition, including the glycemic index (GI) with dyslipidemia and diabetes among the Korean adult population. We analyzed 9,725 subjects (3,795 men and 5,930 women, ≥ 20 years) from the Fourth Korea National Health and Nutrition Examination Survey. Dietary information was collected using single 24-hour recall. Reduced rank regression was used to derive dietary patterns from 22 food groups as predictor variables and four dietary factors related to the quantity and quality of carbohydrates as response variables. Two dietary patterns were identified: 1) the balanced pattern was characterized by high intake of various kinds of foods including white rice, and 2) the rice-oriented pattern was characterized by a high intake of white rice but low intake of vegetables, fruits, meat, and dairy products. Both patterns had considerable amounts of total carbohydrate, but GI values differed. The rice-oriented pattern was positively associated with hypertriglyceridemia in men and low high density lipoprotein-cholesterol in both men and women. The balanced pattern had no overall significant association with the prevalence of dyslipidemia or diabetes, however, men with energy intake above the median showed a reduced prevalence of diabetes across quintiles of balanced pattern scores. The results show that dietary patterns based on carbohydrate nutrition are associated with prevalence of dyslipidemia and diabetes in the Korean adult population.     

Reproducibility and relative validity of dietary glycaemic index and load assessed with a self-administered diet-history questionnaire in Japanese adults

Although many epidemiological studies have examined the association of dietary glycaemic index (GI) and glycaemic load (GL) with health outcomes, information on the reproducibility and relative validity of these variables estimated from dietary questionnaires is extremely limited. We examined the reproducibility and relative validity of dietary GI and GL assessed with a self-administered diet-history questionnaire (DHQ) in adult Japanese. A total of ninety-two Japanese women and ninety-two Japanese men aged 31-76 years completed the DHQ (assessing diet during the preceding month) and 4 d dietary records (DR) in each season over a 1-year period (DHQ1-4 and DR1-4, respectively) and the DHQ at 1 year after completing DHQ1 (DHQ5). We used intraclass correlations between DHQ1 and DHQ5 to assess reproducibility, and Pearson correlations between the mean of DR1-4 and mean of DHQ1-4 and between the mean of DR1-4 and DHQ1 to assess relative validity. Reproducibility correlations for dietary GI and GL were 0.57 and 0.69 among women and 0.65 and 0.58 among men, respectively. Validity correlations for dietary GI and GL assessed by DHQ1-4 were 0.72 and 0.66 among women and 0.65 and 0.71 among men, respectively. Corresponding correlations for DHQ1 were 0.53 and 0.58 among women and 0.57 and 0.60 among men, respectively. White rice was the major contributor to GI and GL in both methods (49-64 %). These data indicate reasonable reproducibility and relative validity of dietary GI and GL assessed by a DHQ for Japanese adults, whose dietary GI and GL are primarily determined by the GI of white rice.     

Glycemic Response of a Carbohydrate-Protein Bar with Ewe-Goat Whey

In this study we examined the glycaemic index (GI) and glycaemic load (GL) of a functional food product, which contains ewe-goat whey protein and carbohydrates in a 1:1 ratio. Nine healthy volunteers, (age, 23.3 ± 3.9 years; body mass index, 24.2 ± 4.1 kg·m²; body fat %, 18.6 ± 10.0) randomly consumed either a reference food or amount of the test food both with equal carbohydrate content in two visits. In each visit, seven blood samples were collected; the first sample after an overnight fast and the remaining six at 15, 30, 45, 60, 90 and 120 min after the beginning of food consumption. Plasma glucose concentration was measured and the GI was determined by calculation of the incremental area under the curve. The GL was calculated using the equation: test food GI/100 g available carbohydrates per test food serving. The GI of the test food was found to be 5.18 ± 3.27, while the GL of one test food serving was 1.09 ± 0.68. These results indicate that the tested product can be classified as a low GI (<55) and low GL (<10) food. Given the health benefits of low glycaemic response foods and whey protein consumption, the tested food could potentially promote health beyond basic nutrition.     

Higher glycemic index and glycemic load diet is associated with increased risk of esophageal squamous cell carcinoma: a case-control study

Several studies have indicated the association between intake of foods high in dietary glycemic index (GI) and glycemic load (GL) with an increased risk of digestive tract cancers. We hypothesized that GI and GL may be associated with risk of esophageal squamous cell carcinoma (ESCC) in a high-risk population in Iran. In total, we interviewed 47 cases with incident of ESCC and 96 frequency-matched hospital controls, then calculated the average dietary GI and GL via a validated food frequency questionnaire. Dietary GL was calculated as a function of GI, carbohydrate content, and frequency of intake of certain foods. Dietary GI and GL levels were significantly higher among the ESCC cases compared with the controls (P < .05). After adjustment for potential confounders, those in the highest tertile of dietary GI had 2.95 times higher risk of ESCC compared with those in the lowest (95% confidence interval, 1.68-3.35; P for trend = .002). In addition, being in the highest tertile of dietary GL was positively associated with an ESCC risk (odds ratio, 3.49; 95% confidence interval, 2.98-4.41; P for trend = .001). Findings of the present study indicate that diets with high GI and GL might have potentially unfavorable effects on ESCC risk and suggest a possible role for excess circulating insulin and related insulin-like growth factor 1 in esophageal cancer development.     

Towards understanding of glycaemic index and glycaemic load in habitual diet: associations with measures of glycaemia in the Insulin Resistance Atherosclerosis Study

Epidemiologic studies have applied the glycaemic index (GI) and glycaemic load (GL) to assessments of usual dietary intake. Results have been inconsistent particularly for the association of GI or GL with diabetes incidence. We aimed to advance understanding of the GI and GL as applied to food frequency questionnaires (FFQ) by evaluating GI and GL in relation to plasma measures of glycaemia. Included were 1255 adults at a baseline examination (1994-6) and 813 who returned for the 5-year follow-up examination. Usual diet, at both examinations, was assessed by a validated FFQ. GI and GL were evaluated in relation to average fasting glucose (two measures at each examination) and 2 h post-75 g glucose load plasma glucose (baseline and follow-up), and glycated haemoglobin (A1c; follow-up only); using generalized linear models. Correlation coefficients (r) for GI and GL related to measures of glycaemia, adjusted for total energy intake, ranged from -0.004 to 0.04 (all NS) for both examinations. Adjustment for potential confounders, for fasting glucose in models for 2 h glucose (to model incremental glucose) and for average fasting glucose in models for A1c (to account, in part, for overnight endogenous glucose production) also did not materially alter findings, nor did inclusion of data from both examinations together in linear mixed models. The present results call into question the utility of GI and GL to reflect glycaemic response to food adequately, when used in the context of usual diet. Further work is needed to quantify usual dietary exposures relative to glucose excursion and associated chronic glycaemia and other metabolic parameters.     

Glycaemic index and glycaemic load in the diet of healthy schoolchildren: trends from 1990 to 2002, contribution of different carbohydrate sources and relationships to dietary quality

Despite intense discussion of the glycaemic index (GI) and glycaemic load (GL) concepts, data on the GI or GL levels in the diet of children are scarce. The present analysis determined trends in the levels of GI or GL of healthy children from 1990 to 2002 and examined the contribution of carbohydrate (CHO) sources to the overall GL, and the relationships of the GI and GL to the overall dietary quality. The analysis includes three cohorts of participants from the Dortmund Nutritional and Anthropometrical Longitudinally Designed study, aged 7-8 years in 1990 (n 53), 1996 (n 46) and 2002 (n 56). A GI value was assigned to all CHO foods recorded over three consecutive days. In comparison with 1990, 7-8-year-old children in 2002 had slightly higher GI (56.5 v. 55.1 %; P=0.03) and GL (17.5 v. 16.7 g/MJ; P=0.04) levels. In all three time periods the combined contribution of the 'tolerated food groups' (i.e. sweets, soft drinks, cakes and cookies, and salty snacks) to the overall GL exceeded that of bread and rolls (1990, 31 v. 24 %; 1996, 29 v. 31 %; 2002, 28 v. 25 %). Conversely, rice and fried or mashed potatoes had only a minor impact. Children in the lowest GI tertile, but not those in the lowest GL tertile, had a better nutrient profile and a more favourable food choice. In conclusion, partial replacement of high-GI 'tolerated food groups' for low-GI foods would help to reverse the slight recent increases in GI and GL, and to improve the overall dietary quality of 7-8-year-old children.     

厦门市城区居民膳食血糖负荷和膳食胰岛素负荷的 现况调查

摘要:目的　了解厦门市城区居民碳水化合物消费情况及膳食血糖负荷及膳食胰岛素负荷的现状,调查膳食血糖负荷及膳食胰岛素负荷与生化指标。方法　根据全国营养调查方案,2010年10-12月对厦门市城区的6个社区居委会成年居民进行调查,采用连续3 d 24 h回顾法对其中的291人进行膳食调查、身体测量及生化指标测量;根据膳食血糖生成指数（GI）和碳水化合物摄入量计算膳食血糖负荷（GL）;根据膳食胰岛素指数（II）和能量及食用频率计算膳食胰岛素负荷（IL）。结果　被调查的厦门市城区成年居民的平均膳食血糖指数为75.2;平均膳食血糖负荷为179.1;平均膳食胰岛素指数为30.4,平均膳食胰岛素负荷为247.2。粮谷类对膳食GL、IL的贡献达92.0%、83.1%。不同GL、IL水平的被调查人群的身体测量及生化指标间的差异无统计学意义;通过多元线性回归分析并未发现膳食GI、GL、II、IL与糖尿病的患病风险有明显的相关性。结论　粮谷类食物是厦门市城区居民膳食GL、IL的主要来源,低膳食GL的人群粮谷类消费低,脂肪消费高,膳食结构不合理;并未发现膳食GL、IL与身体测量及生化指标之间的联系。