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 and glycaemic load values of a selection of popular foods consumed in Hong Kong.

The objective of the present paper is to provide glycaemic index (GI) and glycaemic load (GL) values for a variety of foods that are commonly consumed in Hong Kong and expand on the international GI table of Chinese foods. Fasted healthy subjects were given 50 g of available carbohydrate servings of a glucose reference, which was tested twice, and test foods of various brands of noodles (n 5), instant cereals (n 3) and breads (n 2), which were tested once, on separate occasions. For each test food, tests were repeated in ten healthy subjects. Capillary blood glucose was measured via finger-prick samples in fasting subjects ( - 5, 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 were medium (a GI value of 56-69) to high (a GI value of 70 or more) and compared well with previously published values. More importantly, our dataset provides GI values of ten foods previously untested and presents values for foods commonly consumed in Hong Kong.

Role of body composition in the glycaemic response to foods fed to three different ethnic groups: a pilot study.

AIM: To examine the role of overweight and obesity on the glycaemic response to foods across the whole population. DESIGN: Randomised, repeated measures design. SETTING: Oxford, UK. SUBJECTS AND METHODS: Twenty-seven healthy volunteers, 9 Caucasian, 9 Asian, and 9 African, voluntarily participated in the study. The glycaemic response to two breakfast cereals and two bread types was determined in obese and overweight subjects. RESULTS: The current study shows that a very strong correlation exists between fasting blood glucose, peak change in glucose and the IAUC for glucose with each of BMI and WC (r = 0.88, 0.92; 0.82, 0.82; 0.91, 0.81; p = 0.01, respectively) for the Caucasian group. In addition, there was a strong significant negative association between the mean GI values of the four foods and the BMI for the Caucasian subjects (r = 0.61, p < 0.05). Furthermore, there was a strong positive significant association between the mean GI values of the four foods and the percentage body fat mass for the Asian subjects (r = 0.67, p < 0.05). CONCLUSIONS: This study has shown that the GI values of foods are affected by body composition in Asian and Caucasian subjects.

Energy and nutrient intakes during different phases of the menstrual cycle in females in the United Arab Emirates.

BACKGROUND/AIMS: Evidence related to the influence of the menstrual cycle on energy and nutrient intakes is inconclusive. The purpose of the present study was to investigate energy and nutrient intakes during different phases of the menstrual cycle in adult females in the United Arab Emirates. METHODS: Forty-three females, aged between 18 and 30 years, were recruited to the study. Subjects were not using oral contraceptive pills and experienced regular menstrual cycles. Food and beverage intake was recorded, using the estimated daily record method, for 2 days of each menstrual cycle phase (pre-menstrual, menstrual and post-menstrual). Energy and nutrient intakes were analysed using Diet5 for Windows. RESULTS: Mean energy intake was significantly lower in the menstrual phase compared to the pre-menstrual phase (p = 0.002), but not the post-menstrual phase. Intakes of macronutrients and micronutrients were higher in the pre-menstrual phase compared to the menstrual and post-menstrual phases. Intakes of carbohydrates, protein and fat were significantly higher in the pre-menstrual phase than in the menstrual phase (p = 0.008, p = 0.001, p = 0.013, respectively). Similarly, intakes of vitamin C and B vitamins were significantly higher in the pre-menstrual phase than in the menstrual phase (p = 0.019, p = 0.05, respectively). CONCLUSION: Energy and nutrient intakes varied during the different phases of the menstrual cycle. These results confirm the hypothesis that food intake differs between different phases of the menstrual cycle.

Prevalence of overweight and obesity among adult females in the United Arab Emirates.

The purpose of this present study was to investigate the prevalence of overweight and obesity in adult females in the United Arab Emirates. A total number of 724 females, age 20-90 years, were recruited from the seven Emirates. The sample was divided into three age groups, 20 to <30 years, 30 to <60 years and >60 years. Height, weight and mid-upper-arm circumference were measured in each subject. Overweight and obesity were defined as a body mass index of 25.0-29.9 kg/m2 and >30 kg/m2, respectively. The prevalence of overweight and obesity were 27% and 16%, respectively. The age group between 30 and <60 years had the highest prevalence of overweight (33%) and obesity (24%). In conclusion, the findings from our study suggest that a high proportion of adult females in the United Arab Emirates are overweight and obese. The consequences of this are a serious concern for public health and need to be addressed.

Glycemic response of mashed potato containing high-viscocity hydroxypropylmethylcellulose.

Potatoes generally have one of the highest glycemic index values of any food. Relatively small differences in the glycemic response (GR) of regularly consumed starch foods have shown beneficial effects on health. Lowering the GR of a potato-based meal has potentially wide-reaching health benefits. High-viscosity hydroxypropylmethylcellulose (HV-HPMC) is a modified cellulose dietary fiber extensively used in the food industry. We hypothesized that the GR of a high-glycemic index product such as mashed potato would be lower with the addition of HV-HPMC. In a nonblind, randomized, repeat-measure, crossover controlled trial, 15 healthy adults consumed portions of mashed potato with different doses (0%, 1%, 2%, and 4%) of a specially selected and optimized HV-HPMC and a reference food (glucose) on separate occasions. Five subjects were excluded from the final analysis due to noncompliance with study procedures. Capillary blood glucose was measured in fasted subjects and at 15, 30, 45, 60, 90, and 120 minutes after starting to eat. For each sample, the incremental area under the blood glucose response curve was calculated and the GR determined. There was a significant lowering effect of HV-HPMC on GR (P < .001) of mashed potato. Glycemic responses for all mashed potato samples with the HV-HPMC were significantly lower than the standard mashed potato: 1% level (P < .05), 2% level (P < .05), and 4% level (P < .05). However, there was no significant effect of the HV-HPMC dose on GR. We conclude that addition of select HV-HPMC to mashed potato blunts GR.

The influence of adding fats of varying saturation on the glycaemic response of white bread.

The aim of this study was to examine the effect of three different fats of varying degrees of saturation on the glycaemic response of white bread. Standard white bread was served alone or with 30 g butter, 24.8 g olive oil or 24.8 g grape-seed oil. On separate occasions, 15 subjects consumed the four test foods and reference food (glucose) in 50 g available carbohydrate amounts. Capillary blood glucose was measured from finger-prick samples in fasted subjects (-5 and 0 min) and at 15, 30, 45, 60, 90 and 120 min after starting to eat. All fats lowered the glycaemic response of bread; however, no significant differences in glycaemic index were recorded between the types of fat used when ingested with bread. The results of the present study suggest that the glycaemic response of bread can be lowered using any type of fat; therefore, the use of unsaturated fat is recommended for its potential lipidaemic advantage.

The influence of restrained and external eating patterns on overeating.

Eating in response to an increasingly obesogenic environment has been strongly implicated as a salient aspect of eating behaviour, arguably influenced by learning and experience. Interindividual differences in susceptibility to weight gain may be due, in part, to variability in response to environmental triggers. The phenomenon of food craving may also be an important factor influencing appetite control. The present study tested a model, in which food craving was hypothesised to be an intervening causal variable, on a causal pathway between responsivity to environmental cues and the development of obesity. One hundred and twenty four participants (aged 21-71 years, 83 females and 41 males) completed the study. Participants completed the Dutch eating behaviour questionnaire (DEBQ), measuring external eating (externality), emotional eating (emotionality) and restrained eating behaviour (restraint), and an adapted form of the food craving inventory (FCI), assessing cravings for carbohydrate, fats, sweets and fast food fats, in addition to total food cravings. Initial analysis showed positive correlations between FCI-tot and body mass index (BMI), FCI-fats and BMI and FCI-fast food fats and BMI in both men and women, and between FCI-carbohydrates and BMI in men only. Multiple regression analyses showed externality as the principal predictor of food craving, which was greater in males compared to females, but differential for different food groups between genders. Restrained eating and cravings for fats and fast food fats were negatively associated in women only. As predicted, total cravings, and cravings for fats and fast food foods mediated the positive association between external eating and BMI. It is concluded that appetitive response to external cues as an important risk factor in appetite control is mediated through cravings for particular food groups and is gender-dependent.

Effects of long-term intervention with low- and high-glycaemic-index breakfasts on food intake in children aged 8-11 years.

The aim of the present study was to investigate the effects of long-term intervention of low-glycaemic-index (GI) v. high-GI breakfasts on energy and macronutrient intakes in children aged 8-11 years. Preadolescent children were assigned to one of two groups in a random cross-over design. Each group was given low-GI and high-GI breakfasts on two non-consecutive days per week for 10 weeks per breakfast type. Each breakfast provided approximately 1273 kJ (300 kcal) and was closely matched for macronutrient and dietary fibre content. Subsequent food intake at an ad libitum buffet lunch was recorded and daily energy and macronutrient intakes were measured by 24 h recall and 3 d food diaries. There was a tendency towards a reduced energy intake at lunch following the low-GI breakfast compared with the high-GI breakfast, although the mean difference of 75 kJ (18 kcal) was not significant (P = 0.406). In particular, there was a trend towards a reduced energy intake in the low-GI arm compared with the high-GI arm among boys. In addition, data from the 3 d food diaries showed that there was a tendency towards a reduced energy intake during the low-GI compared with the high-GI study period. In conclusion, although the difference in energy intake following the low-GI and high-GI breakfasts was not statistically significant, the reduced energy intake following the low-GI breakfast is encouraging. Both dietary fibre and carbohydrate type may affect GI, thus their potential and relative modulating effect on appetite requires further investigation.

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.

Influence of bread volume on glycaemic response and satiety.

The role of carbohydrates in health and disease has received a high profile in recent years, in particular the glycaemic index (GI) as a physiological classification of carbohydrate foods. A common carbohydrate source in the UK is white bread, which is considered to have a high GI value and low satiety value. In the present study, the possibility of favourably altering the GI of white bread by manipulating bread structure (loaf form) was investigated. In a randomised repeated-measures design, ten subjects were tested for glycaemic and satiety responses to four loaves of varying volume, but of consistent macronutrient content. Peak plasma glucose levels and GI values were shown to be significantly reduced by lowering loaf volume (P=0.007, P<0.001 respectively). In addition, a greater satiety index (SI) was seen with decreased loaf volume (P<0.001). In conclusion, the present study demonstrates that reducing the volume of white bread, which is generally considered to be high-GI and low-SI, can favourably alter metabolic and appetite responses. Relatively small differences in the GI of regularly consumed starch foods have been shown to have beneficial effects on health.

Glycaemic index values for commercially available potatoes in Great Britain.

The glycaemic response to eight potato varieties commercially available in Great Britain was compared against a glucose standard in a non-blind, randomised, repeated measure, crossover design trial. Seventeen healthy subjects (three males, fourteen females), mean age 32 (sd 13) years and mean BMI 22.3 (sd 3.6) kg/m2, were recruited to the study. Subjects were served portions of eight potato varieties and a standard food (glucose), on separate occasions, each containing 50 g carbohydrate. 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 the consumption of each test food. For each potato variety, the glycaemic index (GI) value was calculated geometrically by expressing the incremental area under the blood glucose curve (IAUC) as a percentage of each subject's average IAUC for the standard food. The eight potato varieties exhibited a wide range in GI values from 56 to 94. A trend was seen whereby potatoes with waxy textures produced medium GI values, whilst floury potatoes had high GI values. Considering the widespread consumption of potatoes in Great Britain (933-1086 g per person per week), this information could be used to help lower the overall GI and glycaemic load of the diets of the British population.

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.

Intra-individual variation in resting metabolic rate during the menstrual cycle.

Little information exists on the extent of day-to-day intra-individual variation in resting metabolic rate (RMR) in women. The present study has investigated the intra-individual variation in RMR of women during the menstrual cycle. Nineteen women (naturally cycling non-pill users) were recruited to the study. Anthropometric and RMR measurements were taken at least three times per week for the duration of one complete menstrual cycle; measurements were taken for a second, consecutive cycle in eight of the nineteen subjects. RMR was measured by indirect calorimetry using a ventilated hood system under standardized conditions. The measurements made throughout each complete menstrual cycle were averaged and the levels of inter- and intra-individual variation in RMR were assessed by determining the CV (%). Mean RMR of the group was 5686 (sd 674) kJ/d; inter-individual variation in RMR was 11.8 %. There were wide differences in the intra-individual variation in RMR of women (CV range 1.7-10.4 %). The CV in ten subjects was small (2-4 %), while the CV in nine women was high (5-10 %), indicating a significant variation in RMR during the menstrual cycle in certain subjects. Using statistical models, it has been shown that there was a significant effect on RMR due to a subject-specific level of variability; this was the case even when accounting for a possible training effect. In conclusion, the findings from our present study show that RMR cannot be assumed to be 'stable' in all women. The implications of intra-individual variation in RMR and its impact on energy balance needs further research.

Prevalence of overweight among adolescent females in the United Arab Emirates.

The purpose of the study was to investigate the prevalence of overweight in adolescent females in the United Arab Emirates (UAE). A total of 898 females, ages 11-18 years, were recruited from five of the seven Emirates with the highest resident Emirati population. Height, weight, triceps skinfold thickness (TSF), and mid-upper-arm circumference were measured in each subject. Reference data from the National Health and Nutrition Examination Surveys (NHANES) were used for comparison. At risk for overweight or overweight were defined as a body mass index (BMI, kg/m(2)) >or=85-95th percentile and >or=95th percentile, respectively. Mean values for BMI and TSF at all ages were higher than the 50th percentile (median) of the NHANES reference data. Using the BMI classification, 14% and 9% of all subjects were classified as at risk for overweight or overweight, respectively. The proportion of subjects at risk for overweight ranged between 7-19% and the prevalence of overweight ranged between 6-15%. The proportion of subjects with a BMI >or=85 percentile ranged from 15% at age 17 years to 33% at age 11 years. Furthermore, 27% and 28% of subjects ages 11 and 12 years, respectively, were above the TSF 90th percentile. These two age groups also showed a high prevalence of overweight using the BMI classification. In conclusion, the findings from our study suggest that a high proportion of adolescent females in the UAE are overweight or at risk for overweight. The consequences of this are a serious concern for public health and need to be addressed.

Physical activity and levels of inactivity in adolescent females ages 11-16 years in the United Arab Emirates.

The purpose of this study was to investigate patterns of physical activity and levels of inactivity in adolescent females in the United Arab Emirates (UAE). A total of 58 adolescent females, age 11-16 years, were recruited from two female-only governmental schools in Abu-Dhabi. Subjects were divided into two groups: 11-13 years (n = 22) and 14-16 years (n = 36). Physical activity patterns were determined from a 3-day activity diary. Total energy expenditure (TEE) was estimated using a factorial approach. The amount of physical activity was expressed as the physical activity level (PAL) and the activity-related energy expenditure (AEE). The number of hours spent watching television was estimated from the activity diaries. There were no significant differences in the energy expenditure parameters between age groups or between schooldays and weekends. PAL was low in both age groups. Television was the predominant leisure time pursuit. The number of hours per day spent watching television (median and interquartile range) was 2.5 (2.3-3.1) in 11-13 years and 2.5 (2.3-2.8) in 14-16 years. Television-watching was significantly higher during the weekend than schooldays: 11-13 years (P = 0.006) and 14-16 years (P < 0.001). In conclusion, the amount of physical activity undertaken by adolescent females in the UAE was very low. Cultural and weather restrictions and social change of the community in the UAE are not conducive to physical activity and play a major role in levels of physical inactivity. This may explain, in part, the rise in the incidence of obesity in this population.

Intra-individual variation in RMR in older people.

In the factorial estimation of total energy expenditure it is assumed that the intra-individual variation in RMR is small. Little is known about the intra-individual variation in RMR in older subjects. The present study investigated the intra-individual variation in RMR in older people. Measurements of RMR were made in twenty-seven older subjects, mean age 71.6 (sd 6.1) years, on two separate occasions (T1 and T2) and on a third occasion (T3) in nineteen of the subjects. Measurements of height and weight were taken in all subjects. RMR measurements were made in the laboratory using a Deltatrac (ventilated-hood indirect calorimeter; Datex, Helsinki, Finland). All subjects had fasted overnight for 12 h and refrained from strenuous exercise before measurements. The intra-individual CV in RMR (kJ/d) after T1 and T2 was 2.5 % in women and 3.6 % in men and was 2.6 % in women and 3.4 % in men after all three sets of measurements. Although mean RMR did not vary across T1, T2 and T3, there was significant "crossing tracks" across the three measurement occasions in some individuals, reflecting a high degree of within-subject variability. The methods used had a significant measurement error associated with them (high R value; significant F ratio in three-way ANOVA). In conclusion, the results from the present study indicate that intra-individual variation in RMR was low in older people. The intra-individual variation in the elderly is similar to that seen in younger age groups.

How well do children aged 5-7 years recall food eaten at school lunch?

OBJECTIVE: This study aimed to determine the accuracy with which children aged 5 to 7 years were able to report the food eaten at a school lunch. SUBJECTS/SETTING: Two hundred and three children (103 boys, 100 girls) aged 5-7 years were recruited from three primary schools in Oxford. DESIGN: Trained investigators made observational records of the school dinner and packed lunch intakes of four or five children per session. Children were interviewed within two hours of finishing the lunchtime meal and asked to provide a free recall of their meal. When the child had completed the recall, non-directive prompts were used to assess if the child was able to remember anything else. Foods recalled were classified as matches (recalled food agreed with observation), omissions (failed to report a food observed) or phantoms (recalled food was not observed). RESULTS: The percentage of accurate recall was significantly higher (P<0.01) in children eating packed lunch (mean 70 +/- 29%) than in children consuming school dinners (mean 58 +/- 27% ). This difference may have been due to increased familiarity of foods in packed lunches. Leftovers were not readily reported in this age group. Prompts and cues enhanced recall by all children. CONCLUSIONS: This study indicated that there was a wide range in the ability of children aged 5-7 years to recall intake from a packed lunch and/or school dinner. This dietary assessment method is unlikely to be suitable at an individual level. Investigators using dietary recall to estimate food intake in children aged 5-7 years need to be aware of the limitations of this method.

Use of natural food flavours to increase food and nutrient intakes in hospitalized elderly in Hong Kong.

The present study investigated the effect of natural food flavours on food and nutrient intake in hospitalized elderly patients in Hong Kong. Food intake was directly measured for breakfast, lunch and dinner over five consecutive days -- two control days and three experimental days. For the three experimental days, six natural food flavours, based on familiarity of use and wide acceptance to the patient population, were added to each standard lunch and dinner meal. Each food item provided to each patient was weighed before and after consumption. Fourteen elderly subjects (>/=65 years; seven males) from Shatin Hospital in Hong Kong participated in the study. The use of natural food flavours in the hospitalized elderly promoted increased food and macronutrient intakes. Total food, energy and fat intakes on day 3 were significantly increased (P=0.037, P=0.008 and P=0.019, respectively). Although total energy and protein intakes were increased by 13-26% and 15-28%, respectively, nutrient intakes remained low compared with requirements. Findings from this pilot study suggest a role for natural food flavours in the elderly. Whether food and nutrient intakes would have shown an increase in the absence of any intervention could not be determined. Further work to investigate the long-term effect of natural food flavours on food and nutrient intakes in the elderly is required.

Brief communication: energy and protein intake in a sample of hospitalized elderly in Hong Kong.

The present study investigated energy and protein intake in 17 hospitalized elderly patients in Hong Kong. Food intake was directly measured for breakfast, lunch and dinner over two consecutive days. Energy intakes were low--the meals provided, on average, 57% and 45% of the calculated basal metabolic rate (BMR) and energy requirement (1.27 x BMR), respectively. Protein intake per kilogram of body weight was below 0.75 g in eight subjects. The type of meat served at both lunch and dinner influenced energy and protein intakes. Energy intake was significantly higher when the meals contained pork, and protein intake was significantly higher when chicken was served. The present study highlights the importance of meat in the diet of the hospitalized elderly patient and indicates the influence that this food may have on energy and protein intakes. Effective strategies to increase energy and protein intakes in the hospitalized elderly are urgently required.