Glycaemic index and glycaemic load of three traditional Mexican dishes

The purpose of the present study was to assess the glycaemic index (GI) and glycaemic load (GL) of different mixed meals traditionally consumed in Mexico. GI was measured for three meals (Pozole, Molletes and Mole), using glucose as a reference in 12 college student subjects. Mole (p?=?0.002), Molletes (p?=?0.043) and Pozole (p?=?0.016) showed a lower IAUC than glucose. However, there was not difference between meals. Higher GI and GL levels were observed than the estimated GI using as reference the International Table of Atkinson et al. (2008. Diabetes Care 31(12):2281-2283). Since food ingredients vary among Mexican regions, it is recommended to assess the GI and GL of mixed meals according to the cooking habits of each region.     

Glycaemic index and glycaemic load intake patterns in older Australian women

Aims:  Dietary glycaemic index and glycaemic load have been associated with risk of chronic diseases, yet limited research exists on patterns of consumption in Australia. Our aims were to investigate glycaemic carbohydrate in a population of older women, identify major contributing food sources and determine low, moderate and high ranges.
Methods:  Subjects were 459 Brisbane women aged 42–81 years participating in the Longitudinal Assessment of Ageing in Women. Diet history interviews were used to assess usual diet and results were analysed into energy and macronutrients using the FoodWorks dietary analysis program combined with a customised glycaemic index database.
Results:  Mean ± SD dietary glycaemic index was 55.6 ± 4.4% and mean dietary glycaemic load was 115 ± 25. A low glycaemic index in this population was ≤52.0, corresponding to the lowest quintile of dietary glycaemic index, and a low glycaemic load was ≤95. Glycaemic index showed a quadratic relationship with age ( P = 0.01), with a slight decrease observed in women aged in their 60s relative to younger or older women. Glycaemic load decreased linearly with age ( P < 0.001). Bread was the main contributor to carbohydrate and dietary glycaemic load (17.1% and 20.8%, respectively), followed by fruit (15.5% and 14.2%), and dairy for carbohydrate (9.0%), or breakfast cereals for glycaemic load (8.9%).
Conclusions:  In this population, dietary glycaemic load decreased with increasing age; however, this was likely to be a result of higher energy intakes in younger women. Focus on careful selection of lower-glycaemic-index items within bread and breakfast cereal food groups would be an effective strategy for decreasing dietary glycaemic load in this population of older women.     

Glycaemic index,glycaemic load and dietary fibre characteristics of two commercially available fruit smoothies

In light of the updated Eatwell Guide and the corresponding change in the consumption of fruit smoothies, the aim of this study was to measure the glycaemic index and load of two commercial fruit smoothies and to investigate the retention of dietary fibre following production. In vitro analysis was performed to identify fibre material (cellulose and pectins) using calcofluor staining and immunocytochemical labelling. A repeated measures cross-over study was conducted (n 10) to determine the glycaemic index (GI) and glycaemic load (GL) of the smoothies. Results showed that dietary fibre was still present in the smoothies after processing (16.9–17.5% cellular material by dry weight). The GI was low for both smoothies (39 and 36), whereas the GL was medium and borderline-low, respectively (11.4 and 9.7). The retention of fibre in these smoothies may have a potential positive effect on glycaemic response and may contribute to daily fibre requirements.     

Glycaemic index of three Indian rice varieties

Three commonly consumed Indian rice varieties (Sona Masuri, Ponni and Surti Kolam) were tested for their glycaemic index (GI). Healthy volunteers were recruited and after an overnight fast were given a 50 g available carbohydrate portion of glucose (reference food) or different varieties of cooked rice (test foods) on separate occasions. The fasting as well as postprandial capillary blood glucose response was determined over 2 h, and the incremental area under the curve (IAUC) was calculated. The GI was calculated as the IAUC of the test food/IAUC of the reference food (glucose) × 100. The differences between the GI values for Sona Masuri (72.0 ± 4.5), Ponni (70.2 ± 3.6) and Surti Kolam (77.0 ± 4.0) rice varieties were non-significant (p = 0.606) and are all classified as high GI varieties of rice. There is an urgent need to study the GI of other commonly consumed rice varieties and to develop rice of a lower GI value.     

Diets with a low glycaemic load have favourable effects on prediabetes progression and regression: a prospective cohort study

Background

To date, no study assessing the associations among glycaemic index (GI ), glycaemic load (GL ) and progression to diabetes has focused specifically on prediabetes. Moreover, the available data on the association between these variables and regression to normal glucose regulation (NGR ) are insufficient. Therefore, the present study aimed to evaluate the longitudinal associations among GI , GL and prediabetes outcomes.

Methods

This prospective study included 640 adults aged 40–79 years with prediabetes at baseline. Dietary data were assessed using a previously validated 3‐day food record. The participants were divided into three groups according to GI and GL tertiles. Outcomes were defined based on annual oral glucose tolerance test results.

Results

During a median of 5 years of follow‐up, 127 incident cases of diabetes and 249 incident cases of NGR were identified. Dietary GL was positively associated with the risk of developing diabetes and negatively associated with the likelihood of reaching NGR at least once. Comparing the highest and lowest tertiles of GL , the multivariable‐adjusted hazard ratios (95% confidence intervals) were 1.85 (1.07–3.21) for progression and 0.65 (0.44‐0.96) for regression. No association was observed between GI and prediabetes outcomes in the fully adjusted models.

Conclusions

Among patients with prediabetes, high dietary GL was positively associated with diabetes risk. Furthermore, a low‐GL diet contributed to an increased incidence of reaching NGR .

     

Food intake and dietary glycaemic index in free-living adults with and without type 2 diabetes mellitus

A recent Cochrane review concluded that low glycaemic index (GI) diets are beneficial in glycaemic control for patients with type 2 diabetes mellitus (T2DM). There are limited UK data regarding the dietary GI in free-living adults with and without T2DM. We measured the energy and macronutrient intake and the dietary GI in a group (n = 19) of individuals with diet controlled T2DM and a group (n = 19) without diabetes, matched for age, BMI and gender. Subjects completed a three-day weighed dietary record. Patients with T2DM consumed more daily portions of wholegrains (2.3 vs. 1.1, P = 0.003), more dietary fibre (32.1 vs. 20.9 g, P < 0.001) and had a lower diet GI (53.5 vs. 57.7, P = 0.009) than subjects without T2DM. Both groups had elevated fat and salt intake and low fruit and vegetable intake, relative to current UK recommendations. CONCLUSIONS: Patients with T2DM may already consume a lower GI diet than the general population but further efforts are needed to reduce dietary GI and achieve other nutrient targets.     

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.     

Glycaemic index and glycaemic load values of commercially available products in the UK

The objective of this paper is to provide glycaemic index (GI) and glycaemic load (GL) values for a variety of foods that are commercially available in the UK and to compare these with previously published values. Fasted subjects were given isoglucidic (50 or 25 g carbohydrate) servings of a glucose reference at least two to three times, and test foods once, on separate occasions. For each test food, tests were repeated in at least eight subjects. Capillary blood glucose was measured via finger-prick samples in fasting subjects (0 min) and at 15, 30, 45, 60, 90 and 120 min after the consumption of each test food. The GI of each test food was calculated geometrically by expressing the incremental area under the blood glucose response curve (IAUC) of each test food as a percentage of each subject's average IAUC for the reference food. GL was calculated as the product of the test food's GI and the amount of available carbohydrate in a reference serving size. The majority of GI values of foods tested in the current study compare well with previously published values. More importantly, our data set provides GI values of several foods previously untested and presents values for foods produced commercially in the UK.     

Glycaemic index and glycaemic load values of cereal products and weight-management meals available in the UK

There is currently an increased global interest in the published glycaemic index (GI) values of foods. The aim of the present work was to supplement a previous study on the glycaemic response of 140 foods available in the UK by studying a further forty-four foods. One hundred and twenty-two healthy subjects, with a mean age of 32.4 (sd 11.4) years and a mean BMI of 23.6 (sd 3.6) kg/m2, were recruited to the study. Subjects were served equivalent available carbohydrate amounts (50 or 30 g) of test foods (cereal products and weight-management meals) and a standard food (glucose) on separate occasions. Capillary blood glucose was measured from finger-prick samples in fasted subjects (0 min) and at 15, 30, 45, 60, 90 and 120 min after starting to eat each test food. For each test food, the GI value was determined, and the glycaemic load was calculated as the product of the GI and the amount of available carbohydrate in a reference serving size. The GI values of the foods tested ranged from 23 to 83. Of the forty-four foods tested, thirty-three were classified as low-GI, eight as medium-GI and three as high-GI foods. Most GI values of the foods tested compared well with previously published values for similar foods. In summary, this study provides reliable GI and glycaemic load values for a range of foods, further advancing our understanding of the glycaemic response of different foods. The data reported here make an important addition to published GI values.     

A nutritional evaluation of various typical Italian breakfast products: a comparison of macronutrient composition and glycaemic index values

Breakfast foods with lower glycaemic responses are associated with better body weight control. Glycaemic index (GI) values of some commonly consumed breakfast foods in Italy were determined and compared, along with macronutrients. Cakes/pastries were low-medium GI (44–60), with high-sugar and saturated fat and low-fibre. Generally, mueslis and breads were medium GI (62–66 and 59–76, respectively) with higher fibre and lower saturated fat and sugar. The addition of spreads to bread lowered GI (47–66) but increased sugar and saturated fat.     

Discriminating between carbohydrate‐rich foods: A model based on nutrient density and glycaemic index

Aim: The aim of this study was to develop a model for conceptualising the nutritional quality of carbohydrate‐rich foods, using nutrient density and glycaemic index. Methods: A nutrient density score based on six distinguishing nutrients was developed. Nutrient density scores and glycaemic indices for 95 carbohydrate‐rich foods were plotted on two dimensional axes, arranged into four carbohydrate quality quadrants. The classifications of foods and groups of foods were then assessed against Australian and American dietary guidelines' recommendations. Results: The model showed considerable capacity to discriminate between the nutritional qualities of carbohydrate‐rich foods. In general, the ranking of foods was consistent with dietary guidelines' recommendations with most core foods including dairy products, legumes, starchy vegetables, breads and breakfast cereals falling into the two highest quality categories. Non‐core foods such as biscuits, donuts, pastries, sweets and soft drinks fell into the lowest quality category. There were two points of inconsistency between the model and the dietary guidelines, in relation to some fruits and cereals. Nutrient density scores for fruits varied widely. Many cereal foods, including rice and pasta, fell in the lower quality categories and were ranked similarly to biscuits and pastries. Total sugar content was a minor discriminator of nutritional quality using this model. Conclusions: Ranking the nutritional quality of carbohydrate‐rich foods using this model suggests that dietary recommendations for cereal foods in dietary guidelines and food guides may need to be reconsidered. More emphasis may need to be placed on nutrient density and less on sugar content.     

Predictors of undergraduates' intention to incorporate glycaemic index into dietary behaviour

Aim:  The present study used an extension of the theory of planned behaviour to analyse undergraduates' intention to perform behaviour related to the glycaemic index of food. The extended model incorporated measures of past behaviour and pre-existing knowledge about glycaemic index.
Methods:  Seventy-two participants read an academic journal article about glycaemic index and completed questionnaires measuring predictor components of the theory of planned behaviour model.
Results:  Subjective norm and attitude were generally observed to be the best predictors of intention. Pre-existing knowledge about glycaemic index and attitude towards restrained eating were generally found to be poor predictors of intention. Past behaviour exhibited a positive relationship with intention.
Conclusions:  Interventions that focus on dietary behaviour related to the glycaemic index of food should involve individuals who have relationships of influence with the target demographic, such as friends and family, and will need to address modifying ingrained patterns of behaviour.     

An retrospective audit of patients with polycystic ovary syndrome: the effects of a reduced glycaemic load diet

Background  Polycystic ovary syndrome (PCOS) is characterized by hyperandrogenism and chronic anovulation. The aim of this retrospective audit was to determine the patient profile, including anthropometrics, biochemistry and symptoms, and to evaluate the influence of a dietary intervention in women with PCOS.
Methods  Data were collected retrospectively from dietetic and medical records from all PCOS patients ( n  = 88) who attended a dietetic consultation from July 2004 to July 2006. As standard clinic practice, a reduced glycaemic load diet had been prescribed, with energy reduction in overweight patients. Follow-up data were available for 59 patients.
Results  Fifty-eight patients had a body mass index (BMI) ≤ 24.9 kg m⁻² and 30 had a BMI ≥ 25 kg m⁻². Thirty-six patients, with a BMI ≤ 24.9 kg m⁻², self-reported central weight gain at their initial appointment. Over two-thirds of patients self-reported one or more of the following symptoms: carbohydrate cravings, hypoglycaemia, tiredness and hunger. At the follow-up appointment, BMI and waist circumference significantly decreased in overweight patients ( P  < 0.05). Seventy-one percent of women self-reported hypoglycaemia initially; this was reduced to 13% at follow-up ( P  < 0.01).
Conclusions  The audit indicated a low glycaemic load diet in combination with medication may contribute to an improvement in symptom relief in patients with PCOS.     

Periconceptional glycaemic load and intake of sugars and their association with neural tube defects in offspring

In a California population, we previously observed increased neural tube defect (NTD) risks associated with maternal intakes of periconceptional diets predicting higher glycaemic responses and higher sucrose. Our objective here was to replicate these results in a larger study of multiple regions within the United States. This population‐based case–control study included deliveries from 1997 to 2003 from the National Birth Defects Prevention Study. NTD cases were infants or fetuses born with spina bifida or anencephaly. Infants without malformations were eligible as controls. Interview participation was 71% among case mothers and 68% among control mothers. There were 720 NTD case and 4699 control mothers with completed interviews included in analyses. Diet was assessed using a 58‐item food frequency questionnaire focusing on the year before conception, whereas cereals, beverages and supplement use was assessed periconceptionally. We found no increased risks of NTD‐affected pregnancies with increased intakes (adjusted for kcal/day) of sucrose, glucose, fructose or with maternal diets with a higher glycaemic load. The reasons for current findings to be inconsistent with previous findings are unknown.     

Feasiblity of The G.I. guide to increase knowledge about the glycaemic index in practice

Background Research findings support the application of the glycaemic index concept in the dietary treatment of diabetes. However, it is still unclear how to use this concept in general practice. The G.I. guide was accordingly developed to be used as an educational tool when introducing the glycaemic index in practice.
Methods A sample of 21 professionals involved with the treatment of diabetes (expert population), and 18 individuals with diabetes (lay population), were included in a pilot study to determine the feasibility of The G.I. guide to increase knowledge about the glycaemic index in practice. All participants were asked to complete a knowledge questionnaire on the glycaemic index before and directly after meeting and discussing The G.I. guide.
Results The mean change in knowledge about the glycaemic index before and after being exposed to The G.I. guide was highly significant in both the expert ( P  < 0.0001) and the lay group ( P  < 0.0001). The G.I. guide did not change lay or expert participants' opinions about healthy eating guidelines.
Conclusion The G.I. guide was effective in increasing knowledge and raising interest about the glycaemic index in practice.     

Low glycaemic index dietary interventions in youth with cystic fibrosis: a systematic review and discussion of the clinical implications

A systematic review was conducted to assess what is known about the effect of low glycaemic index (GI) diets on glycaemic control, weight and quality of life in youth with cystic fibrosis (CF). Eligibility criteria were systematic reviews, randomised and non-randomised trials of low GI dietary interventions in CF. Outcomes examined were glycaemic control, quality of life, anthropometry and respiratory function. Reference lists were manually searched and experts in the field were consulted. Four studies met the eligibility criteria; two were excluded because they did not include data on any of the outcomes. The remaining two were studies that examined GI secondary to any other intervention: one used GI as a factor in enteral feeds and the other incorporated low GI dietary education into its treatment methodology. There is insufficient evidence to recommend use of low GI diets in CF. Since there is evidence to support use of low GI diets in type 1, type 2 and gestational diabetes, low GI diets should be tested as an intervention for CF. The potential risks and benefits of a low GI diet in CF are discussed.