High-carbohydrate-low-glycaemic index dietary advice improves glucose disposition index in subjects with impaired glucose tolerance

Controversy exists about the optimal amount and source of dietary carbohydrate for managing insulin resistance. Therefore, we compared the effects on insulin sensitivity (SI), pancreatic responsivity (AIRglu) and glucose disposition index of dietary advice aimed at reducing the amount or altering the source of dietary carbohydrate in subjects with impaired glucose tolerance (IGT). Subjects were randomized to high-carbohydrate-high-glycaemic index (GI) (high-GI, n 11), high-carbohydrate-low-GI (low-GI, n 13), or low-carbohydrate-high-monounsaturated fat (MUFA, n 11) dietary advice, with SI, AIRglu and DI measured using a frequently sampled, intravenous glucose tolerance test before and after 4 months treatment. Carbohydrate and fat intakes and diet GI, respectively, were: high-GI, 53 %, 28 %, 83; low-GI, 55 %, 25 %, 76; MUFA, 47 %, 35 %, 82. Weight changes on each diet differed significantly from each other: high-GI, -0.49 (sem 0.29) kg; low-GI, -0.19 (sem 0.40) kg; MUFA +0.27 (sem 0.45) kg. Blood lipids did not change, but glycated haemoglobin increased significantly on MUFA, 0.02 (sem 0.11) %, relative to low-GI, -0.19 (sem 0.08) %, and high-GI, -0.13 (sem 0.14) %. Diastolic blood pressure fell by 8 mmHg on low-GI relative to MUFA (P=0.038). Although SI and AIRglu did not change significantly, DI, a measure of the ability of beta-cells to overcome insulin resistance by increasing insulin secretion, increased on low-GI by >50 % (P=0.02). After adjusting for baseline values, the increase in DI on low-GI, 0.17 (sem 0.07), was significantly greater than those on MUFA, -0.09 (sem 0.08) and high-GI, -0.03 (sem 0.02) (P=0.019). Thus, the long-term effects of altering the source of dietary carbohydrate differ from those of altering the amount. High-carbohydrate-low-GI dietary advice improved beta-cell function in subjects with IGT, and may, therefore, be useful in the management of IGT.     

Development of food groupings to guide dietary advice for people with diabetes

Objective: To describe the development and characteristics of a food categorisation system and its application to guide advice for diabetes treatment. Design and methods: Foods commonly consumed by 16 adults with diabetes were grouped by macronutrient content and type of fat to form a set of reference food groups for dietary advice. Means for energy and macronutrients from individual food groups were then used to construct an overall intake pattern targeting 8000 kJ and relative amounts of carbohydrate, protein and fat (saturated fatty acids (SFA) < 10%E and (polyunsaturated fatty acids) PUFA ～ 10%E). Variation in energy and macronutrients contributed by all foods partitioned into each food group was assessed by the coefficient of variation of data on the whole diet. Results: To differentiate between sources of fat, 13 food groups emerged and 10 were deemed acceptable to nutritional guidelines for diabetes treatment. The food group pattern was judged adequate for the achievement of dietary recommendations with low‐potential variation in total energy (5%) and macronutrient proportions (protein 6%, fat 6%, carbohydrate 3%), but higher for fat types (SFA 22%, (monounsaturated fatty acids) MUFA 11%, PUFA 12%). Targeted proportions for fat types were achieved only when daily servings of PUFA‐rich, oils, nuts and oily fish or soy were included in an ideal intake pattern. Conclusions: In theory, a dietary pattern constructed from food group sources of macronutrients and individual fat types results in low‐potential variation from recommended nutrient targets and, therefore, is appropriate to guide advice for the treatment of diabetes.     

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.     

Structured dietary advice incorporating walnuts achieves optimal fat and energy balance in patients with type 2 diabetes mellitus

OBJECTIVE: A cardioprotective dietary fat profile is recommended for the treatment of type 2 diabetes. The clinical feasibility of advice strategies targeting specific fatty acid intakes and the extent to which they can be achieved by free-living populations needs to be tested. Walnuts, with high n-3 polyunsaturated fatty acid (PUFA) content, may help optimize fatty acid intakes, but regular consumption might increase total fat and energy intakes. This study examined whether advice that refers to a total dietary pattern inclusive of walnuts would result in low-fat energy-controlled diets with optimal dietary fat proportions for patients with type 2 diabetes mellitus. RESEARCH DESIGN AND METHODS: A parallel-design, controlled trial was completed by 55 free-living men and women with established type 2 diabetes mellitus. Participants were randomly assigned to one of three groups: low-fat (general advice), modified low-fat (total diet advice using exchange lists to differentiate PUFA-rich foods), walnut-specific (modified low fat including 30 g walnuts/day). Dietary intakes and clinical outcomes were measured at baseline, and at 3 and 6 months. Dietary goals were: less than 10% of energy from saturated fat, 7% to 10% of energy from PUFA, adequate n-3 PUFA (>or=2.22 g alpha-linolenic acid, >or=0.65 g eicosapentaenoic acid [EPA]+docosahexaenoic acid [DHA]) and n-6 to n-3 ratio less than 10. The proportion of subjects achieving dietary goals and major food sources of fat were determined. RESULTS: At baseline, dietary intakes were not significantly different between groups. No group and few individuals (10%) were consuming adequate PUFA, with meat the main source of dietary fat (22% total dietary fat). At 3 and 6 months, energy and macronutrient intakes were similar among groups. The walnut group, however, was the only group to achieve all fatty acid intake targets (P <.01), and had the greatest proportion of subjects achieving targets ( P <.05). Walnuts were the main source of dietary fat (31%) and n-3 PUFA (50%), while 350 g oily fish/day provided a further 17% n-3 PUFA consumed by this group. CONCLUSIONS: Specific advice for the regular inclusion of walnuts in the context of the total diet helps achieve optimal fat intake proportions without adverse effects on total fat or energy intakes in patients with type 2 diabetes mellitus.     

Energy intake and dietary macronutrient content in women with anorexia nervosa and volunteers

This study was designed to compare the dietary intakes of patients with anorexia nervosa and normal controls. Twenty-four patients hospitalized for treatment of anorexia nervosa were compared with 10 normal controls. Patients ate a self-selected diet and maintained their admission weight to within 1.0 kg during this period (19 +/- 3 days). Food chosen by each subject was weighed before and after meals, and intake was determined to be the difference. Intakes of food energy, protein, fat, and carbohydrate were calculated. Patients were closely monitored to ensure that no disposal of food occurred. Patients with anorexia nervosa had a mean daily energy intake of 1,017 +/- 54 kcal (mean +/- SEM), significantly lower than the mean energy intake for controls (1,651 +/- 108 kcal). Similarly, mean intakes of macronutrients (41 +/- 4 gm protein, 34 +/- 2 gm fat, and 136 +/- 9 gm carbohydrate) were significantly lower for patients than for controls (68.5 +/- gm protein, 65 +/- 6 gm fat, and 204 +/- 13 gm carbohydrate). However, when protein, fat, and carbohydrate were assessed as a percent of total calories, there were no significant differences between patients and controls. There were also no significant differences in calories consumed per kilogram body weight. Underweight patients with anorexia nervosa who maintain their weight on an unrestricted hospital diet have energy intake per kilogram body weight and dietary macronutrient content indistinguishable from those of normal women.     

Reported dietary intakes of patients with insulin-dependent diabetes mellitus: limitations of dietary recall.

Reported dietary intakes were assessed in young patients with insulin-dependent diabetes mellitus (IDDM). We studied 44 IDDM patients (24 males, 20 females, mean +/- SD age 13.2 +/- 4.5 yr) and compared them with 44 healthy age- and sex-matched control subjects. Estimated intakes from 24-h dietary recall were analyzed in relation to body weight and degree of diabetes control. The reported energy intake of the IDDM patients with greater than 120% ideal body weight (IBW) for height was 66, 59/88% (where X = geometric mean, L1 = lower confidence limit/L2 = upper confidence limit) of recommended daily allowance (RDA), whereas those with IBW less than 120% reported 90, 67/120% (p less than 0.01). Patients with increased weights in comparison with IBW had higher hemoglobin A1c (HbA1c) levels (11.9 +/- 2.7%) than those with weights more appropriate for IBW (9.7 +/- 2.4%, p less than 0.025). IDDM patients reported overconsumption of protein and fat, but their carbohydrate intake was low. Analysis of dietary recalls revealed high protein intake (X +/- SD, 20.0 +/- 5.0% of total calorie intake), especially in older (27 +/- 4%) compared with younger (19 +/- 2%-19 +/- 4%, p less than 0.01) patients. Proportions of carbohydrate, protein, and fat did not correlate with variations in body weight and/or HbA1c. The reported intake of protein per kilogram body weight was not significantly different between appropriate-weight and overweight IDDM patients. There was no significant difference in reported total energy intakes of IDDM patients compared with their healthy control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)     

Dietary composition and physiologic adaptations to energy restriction

BACKGROUND: The concept of a body weight set point, determined predominantly by genetic mechanisms, has been proposed to explain the poor long-term results of conventional energy-restricted diets in the treatment of obesity. OBJECTIVE: The objective of this study was to examine whether dietary composition affects hormonal and metabolic adaptations to energy restriction. DESIGN: A randomized, crossover design was used to compare the effects of a high-glycemic-index (high-GI) and a low-glycemic-index (low-GI) energy-restricted diet. The macronutrient composition of the high-GI diet was (as percent of energy) 67% carbohydrate, 15% protein, and 18% fat and that of the low-GI diet was 43% carbohydrate, 27% protein, and 30% fat; the diets had similar total energy, energy density, and fiber contents. The subjects, 10 moderately overweight young men, were studied for 9 d on 2 separate occasions. On days -1 to 0, they consumed self-selected foods ad libitum. On days 1-6, they received an energy-restricted high- or low-GI diet. On days 7-8, the high- or low-GI diets were consumed ad libitum. RESULTS: Serum leptin decreased to a lesser extent from day 0 to day 6 with the high-GI diet than with the low-GI diet. Resting energy expenditure declined by 10.5% during the high-GI diet but by only 4.6% during the low-GI diet (7.38 +/- 0.39 and 7.78 +/- 0.36 MJ/d, respectively, on days 5-6; P = 0.04). Nitrogen balance tended to be more negative, and energy intake from snacks on days 7-8 was greater, with the high-GI than the low-GI diet. CONCLUSION: Diets with identical energy contents can have different effects on leptin concentrations, energy expenditure, voluntary food intake, and nitrogen balance, suggesting that the physiologic adaptations to energy restriction can be modified by dietary composition.     

Dietary patterns in patients with advanced cancer: implications for anorexia-cachexia therapy

BACKGROUND: Severe malnutrition and wasting are considered hallmarks of advanced malignant disease, and clinical research into anorexia-cachexia therapy and nutritional support for cancer patients is ongoing. However, information on typical dietary intakes and food choices for this population is notably lacking; proposed therapies for anorexia and wasting are not framed within the context of current intake. OBJECTIVE: The objective of the study was to characterize the food intake patterns of patients with advanced cancer. DESIGN: Patients with advanced cancer (n = 151) recruited from a regional cancer center and palliative-care program completed a 3-d dietary record a mean (+/-SD) 8 +/- 7 mo before death. Food items were categorized according to macronutrient content and dietary use and subsequently entered into cluster analysis. RESULTS: Wide variations in intakes of energy (range: 4-53 kcal . kg body wt(-1) . d(-1); x +/- SD: 25.1 +/- 10.0 kcal . kg body wt(-1) . d(-1)) and protein (range: 0.2-2.7 g . kg body wt(-1) . d(-1); x +/- SD: 1.0 +/- 0.4 g . kg body wt(-1) . d(-1)) were observed. Even the subjects with the highest intakes had a recent history of weight loss, which suggests that the diets of those persons were consistently inadequate for weight maintenance. Cluster analysis found 3 dietary patterns that differed in food choice and caloric intake. Low intakes and a high risk of weight loss were associated with decreased frequency of eating and dietary profiles with little variety and unusually high proportions of liquids. CONCLUSION: These data provide a glimpse into dietary habits toward the end of life. Unique dietary patterns were found in this nutritionally vulnerable patient population.     

Minimizing random error in dietary intakes assessed by 24-h recall, in overweight and obese adults

OBJECTIVE: To determine the minimum number of days of dietary intake interviews required to reduce the effects of random error (day-to-day variability in dietary intake) when using the multiple-pass, multiple-day, 24-h recall method. DESIGN: Cross-sectional study. SETTING: University research department. SUBJECTS: A total of 50 healthy non-smoking overweight and obese (body mass index=26-40 kg/m2) adult men and women aged 39-45 years completed the study. Participants were randomly selected from volunteers for a larger unrelated study. INTERVENTIONS: Each participant completed 10, multiple-pass, 24-h recall interviews on randomly chosen days over 4 weeks. The minimum number of record days was determined for each macronutrient (carbohydrate, fat, protein) and energy, for each gender, to obtain a 'true' (unobservable) representative intake from reported (observed) dietary intakes. RESULTS: The greatest number of days required to obtain a 'true' representative intake was 8 days. Carbohydrate intakes required the greatest number of days of dietary record among males (7 days), whereas protein required the greatest number of days among females (8 days) in this cohort. Sunday was the day of the week that showed greatest variability in macronutrient intakes. Protein (P<0.05) and fat (P<0.001) intakes were significantly more variable than carbohydrate on Sundays compared with weekdays, for both men and women. CONCLUSION: A logistically achievable 8 days of dietary intake interviews was sufficient to minimize the effect of random error when using the multiple-pass, 24-h recall dietary intake method. Sunday should be included among the dietary interview days to ensure a 'true' representation of macronutrient intakes. This method can be confidently applied to small cohort studies in which dietary intakes from different groups are to be compared or to investigations of associations between nutrient intakes and disease.     

53例糖尿病患者膳食中膳食纤维的摄入量调查

目的调查糖尿患者总膳食纤维、可溶及不可溶性膳食纤维的摄入量,为糖尿患者膳食纤维营养状况的研究提供重要基础数据。方法通过不同实验室间的比对研究建立膳食纤维酶重量分析方法。采用称重法和食物计量图片法登记53例糖尿患者连续3d每餐的食物摄入种类和重量,利用酶重量法建立的食物中膳食纤维数据库计算膳食纤维摄入的数量和种类。结果3个实验室测定膳食纤维数据的相对标准偏差在2.63%~9.67%之间。调查对象蔬菜类食物摄入量最多,是膳食纤维的主要来源。调查对象总膳食纤维摄入量为(26.5±9.8)g/d,不可溶性膳食纤维摄入量为(14.6±5.8)g/d,可溶性膳食纤维摄入量为(10.4±4.4)g/d。结论本次调查对象的总膳食纤维日摄入量处于美国糖尿病协会推荐摄入量范围内。     

Disagreement of energy and macronutrient intakes estimated from a food frequency questionnaire and 3-day diet record in girls 4 to 9 years of age

BACKGROUND: The Block98 food frequency questionnaire (FFQ) has been validated for dietary assessment of usual intakes in adults, but not in children. OBJECTIVE: To assess the agreement of the Block98 FFQ and 3-day diet records for measuring dietary intakes in young girls. SUBJECTS/SETTING: Healthy 4- to 9-year-old girls (N=61; 6.5+/-1.6 years) were recruited from the Athens/Clarke county area in Georgia. DESIGN: Dietary intakes were measured using the Block98 FFQ and 3-day diet records, with nutrient analysis of the 3-day diet records conducted using the Food Processor computer program (ESHA; version 7.21, 1998, ESHA Research, Salem, OR). The Block98 FFQ was completed by a trained interviewer and parent, with input from the child, if able. Food models and portion size pictures were used to increase reporting accuracy. STATISTICAL ANALYSIS: Paired sample t tests and simple regression were conducted to determine whether the two diet instruments reported similar values for energy and macronutrients. RESULTS: Block98 FFQ overestimated intakes from 3-day diet records for energy (2,180+/-692 vs 1,749+/-328 kcal), protein (68.3+/-25.9 vs 57.9+/-14.8 g/day), carbohydrate (298.7+/-97.0 vs 244.7+/-46.1 g/day) and fat (83.6+/-30.5 vs 62.3+/-14.7 g/day) (P<.05). Furthermore, the nutrients assessed using the two different methods were only moderately correlated (range: r=0.40 to 0.55). APPLICATIONS/CONCLUSIONS: The Block98 FFQ agreed weakly to moderately with the 3-day diet records, and resulted in consistently higher intakes of all nutrients. These findings suggest that additional work is needed to develop a FFQ that reflects young children's energy and macronutrient intakes.     

Optimizing dietary fat in a weight-loss trial requires advice based on a structured “whole-of-diet” model

Dietary trials may link macronutrient intakes to health outcomes, but adherence to dietary targets requires advice based on an understanding of food composition and consumption patterns. Using data from a weight loss trial, we hypothesized that structured advice would be required for significant fat modification to occur. We compared participants' food choice patterns in response to advice based on a structured “whole-of-diet” model vs a general approach to healthy eating. Overweight participants (n = 122) were randomized to 2 advice arms (saturated fat [SFA] < 10% energy [E]): (1) general low fat (LF) control—(a) isoenergy, (b) −2000 kJ; and (2) structured LF high polyunsaturated fat (PUFA) (∼10% energy PUFA; PUFA to SFA ratio ≥1) (LF-PUFA)—(a) isoenergy, (b) −2000 kJ. Intakes of E and fat and fat from food groups (percentage of total fat intake) were compared at baseline, 3 months, P < .05. Baseline diets were similar, with most fat from high-SFA foods (59%): meat and milk-based staple meals and high-fat snacks. By 3 months, all groups reduced E and met the SFA target. Polyunsaturated fat targets were met by the LF-PUFA groups only (P < .001), enabling targeted between-group differences. In response to general advice, LF groups simply switched to LF alternatives of the same foods (P < .05). In comparison, LF-PUFA groups shifted fat intake to high-PUFA choices (54%), consuming more fat than controls from nuts (P < .001), whole grains (P < .001), and oils and spreads (P < .05). Significant reductions in E were achieved regardless of advice, but significant shifts in dietary fat profile relied on structured whole-of-diet advice on a range of meal and snack food sources of fat subtypes.     

Evaluation of energy, nutrient and dietary fiber intakes of adolescent males

OBJECTIVE: The minimal data available on the current energy, nutrient and dietary fiber intakes of adolescent males challenges the development of effective nutrition education programs. There is a need for research into the current intakes of adolescent males and in particular their relation to the current Dietary Reference Intakes (DRIs). The primary objective of this study was to assess the diet of adolescent males and relate energy, nutrient and dietary fiber intakes to the DRIs. Secondary objectives were to relate energy, macronutrient and dietary fiber intakes to body mass index (BMI)-for-age percentile categories as well as to explore vitamin/mineral supplement use and soft drink consumption. METHODS: Three-day food records were completed by 180 healthy adolescent males for analysis of energy, nutrient and dietary fiber intakes from food and supplements. Following adjustment for intra-individual variability, nutrient intake percentile distributions were related to the DRIs. Energy, macronutrient and dietary fiber intakes were compared among BMI-for-age percentile categories and diets were evaluated for vitamin/mineral supplement use and soft drink consumption. RESULTS: Median intakes for percent energy from carbohydrate, fat and protein were within the Accepted Macronutrient Distribution Ranges. Intakes of micronutrients with Estimated Average Requirement values indicated that greater than 50% of subjects consumed inadequate amounts of vitamin A and vitamin B6, and greater than 75% of subjects consumed inadequate amounts of magnesium, phosphorus and zinc. Subjects classified as overweight had significantly lower energy and carbohydrate intakes compared with subjects classified as having an acceptable body weight. The prevalence of vitamin/mineral supplement use was 16.1% and 67% of subjects reported daily consumption of soft drinks. CONCLUSION: Results of this study reveal that adolescent males are consuming the recommended amounts of macronutrients but may be at risk for consuming inadequate levels of specific micronutrients. Nutrition education programs should consider targeting select micronutrients to improve nutritional intakes of adolescent males.     

The role and requirements of digestible dietary carbohydrates in infants and toddlers

Digestible carbohydrates are one of the main sources of dietary energy in infancy and childhood and are essential for growth and development. The aim of this narrative review is to outline the intakes of digestible carbohydrates and their role in health and disease, including the development of food preferences, as well the consequences of excess carbohydrate. Key experts in these fields provided up-to-date reviews of the literature. A search of available information on dietary intakes of children below the age of 4 years was conducted from 1985 up to 2010. Articles and reports including information about sugars and/or starch intakes were selected. A number of factors limit the ability to obtain an overall picture of carbohydrate intakes and food sources in this age group. These include small numbers of intake studies, differing approaches to analysing carbohydrate, a variety of terms used to describe sugars intakes and a dearth of information about starch intakes. Data suggest that sweet taste is preferred in infancy and later food choices. There are few established adverse consequences of high intakes of digestible carbohydrate for young children. The greatest evidence is for dental caries, although this is influenced by high intake frequency and poor oral hygiene. Evidence for detrimental effects on nutrient dilution, obesity, diabetes or cognition is limited. In infants, minimum carbohydrate (mainly lactose) intake should be 40% of total energy, gradually increasing to 55% energy by the age of 2 years.     

Use of low-fat foods by people with diabetes decreases fat, saturated fat, and cholesterol intakes

OBJECTIVE: To investigate the effect of providing free access to several fat-modified foods on dietary energy and macronutrient intake in people with and without diabetes mellitus. DESIGN: Five low-fat or no-fat products or their regular-fat counterparts were provided to volunteers to take home and use for 3 days (low-fat condition or regular-fat condition) in a repeated-measures crossover design. People with diabetes were case matched to people without diabetes. Food intakes were determined through a weighed food diary and by weighing the food provided before consumption and the uneaten portions after consumption. SUBJECTS: Thirty men and women, aged 20 to 60 years, with (n = 15) and without (n = 15) diabetes participated. STATISTICAL ANALYSES: Repeated-measures analysis of variance was used to determine the effects of diabetes and use of fat-modified foods on nutrient and energy intake. RESULTS: People with diabetes responded the same way to fat-modified foods as people without diabetes. There was a significant reduction in the grams of fat consumed during the low-fat condition compared with the regular-fat condition (average decrease = 8 g, P < .05). Energy intake from experimental foods was significantly lower during the low-fat condition (271 +/- 181 kcal) compared with the regular-fat condition (353 +/- 256 kcal), but total energy intake was not different. Percentage of energy from fat was significantly decreased in the low-fat condition (27 +/- 7) compared with the regular-fat condition (34 +/- 9; P < .05). There was a corresponding increase in the percentage of energy from carbohydrates in the low-fat condition compared with the regular-fat condition, but no significant increase in grams of carbohydrate consumed. Cholesterol and saturated fat intakes were significantly less in the low-fat condition than in the regular-fat condition. CONCLUSION: Consumption of fat-modified foods by individuals with diabetes may help decrease intake of fat, cholesterol, and saturated fat.     

Correlation between dietary glycemic index and cardiovascular disease risk factors among Japanese women

OBJECTIVE: To examine the correlation between dietary glycemic index (GI) and cardiovascular disease (CVD) risk factors among subjects who consume white rice as a staple food. DESIGN: A cross-sectional study was conducted to explore the associations between dietary GI, dietary glycemic load (GL) and dietary intakes, and CVD risk factors. Dietary GI and GL were calculated from a 3-day (including two consecutive weekdays and one holiday) dietary records. SETTING: A weight-reduction program at a municipal health center in Tokyo, Japan. SUBJECTS: A total of 32 women aged 52.5+/-7.2 y participated in the weight-reduction program. RESULT: The GI food list made for the current study calculated for 91% of carbohydrate intakes measured. The mean dietary GI was 64+/-6, and the mean dietary GL was 150+/-37. Individuals in the highest tertile of GI consumed more carbohydrate, mostly from white rice (P<0.001), and less fat (P<0.01). Individuals in all three groups by tertile of GL showed similar tendencies. In the lowest GI tertile, the highest concentration of HDL-cholesterol and lowest concentration of triacylglycerol and immunoreactive insulin were observed (P<0.01). In the lowest GL tertile, the highest concentration of HDL-cholesterol and the lowest concentration of triacylglycerol were observed (P<0.05). CONCLUSION: Calculated dietary GI and GL were positively associated with CVD risk factors among the Japanese women who consumed white rice as a staple food.     

The Canadian Trial of Carbohydrates in Diabetes (CCD), a 1-y controlled trial of low-glycemic-index dietary carbohydrate in type 2 diabetes: no effect on glycated hemoglobin but reduction in C-reactive protein

BACKGROUND: The optimal source and amount of dietary carbohydrate for managing type 2 diabetes (T2DM) are unknown. OBJECTIVE: We aimed to compare the effects of altering the glycemic index or the amount of carbohydrate on glycated hemoglobin (HbA1c), plasma glucose, lipids, and C-reactive protein (CRP) in T2DM patients. DESIGN: Subjects with T2DM managed by diet alone (n=162) were randomly assigned to receive high-carbohydrate, high-glycemic-index (high-GI), high-carbohydrate, low-glycemic-index (low-GI), or low-carbohydrate, high-monounsaturated-fat (low-CHO) diets for 1 y. RESULTS: The high-GI, low-GI, and low-CHO diets contained, respectively, 47%, 52%, and 39% of energy as carbohydrate and 31%, 27%, and 40% of energy as fat; they had GIs of 63, 55, and 59, respectively. Body weight and HbA1c did not differ significantly between diets. Fasting glucose was higher (P=0.041), but 2-h postload glucose was lower (P=0.010) after 12 mo of the low-GI diet. With the low-GI diet, overall mean triacylglycerol was 12% higher and HDL cholesterol 4% lower than with the low-CHO diet (P<0.05), but the difference in the ratio of total to HDL cholesterol disappeared by 6 mo (time x diet interaction, P=0.044). Overall mean CRP with the low-GI diet, 1.95 mg/L, was 30% less than that with the high-GI diet, 2.75 mg/L (P=0.0078); the concentration with the low-CHO diet, 2.35 mg/L, was intermediate. CONCLUSIONS: In subjects with T2DM managed by diet alone with optimal glycemic control, long-term HbA1c was not affected by altering the GI or the amount of dietary carbohydrate. Differences in total:HDL cholesterol among diets had disappeared by 6 mo. However, because of sustained reductions in postprandial glucose and CRP, a low-GI diet may be preferred for the dietary management of T2DM.     

Observations in energy and macronutrient intake during prolonged bed-rest in a head-down tilt position

OBJECTIVE: to report observations in energy and macronutrient intakes, and body weight during prolonged bed-rest in a head down tilt (HDT) position. DESIGN: open study, each subject was his own control, and was studied during 14 days of baseline, 42 days of -6 degrees HDT bed-rest, and 12 days of recovery. SUBJECTS: eight healthy young man were recruited, one dropped out. METHODS: energy and macronutrient content of the diet were calculated from weighed amounts of food consumed and French food composition tables. RESULTS: body weight declined during HDT (74.0+/-3.2 to 71.8+/-3.2 kg, P< 0.001) and increased during recovery (72.7+/-3.2 kg, P< 0. 001). Energy intake decreased during HDT (by 17% after 4-5 weeks) and increased during recovery but remained lower than during baseline (P< 0.001). During HDT fat intake, expressed by a percentage of energy, decreased (P< 0.01) while carbohydrate increased (P= 0.04); protein intake did not change (P= 0.08). The reverse trends were observed during recovery. CONCLUSIONS: the present study reports a spontaneous reduction in energy and relative fat intake during prolonged HDT bed rest. We believe that these findings have implications for the clinical setting.     

A comparison of three dietary methods for estimating vitamin A intake

This study compared and evaluated vitamin A intake measured by three dietary methods (the 24-hour recall, the three-day food record, and a food frequency questionnaire) in 82 adult men enrolled in the Multiple Risk Factor Intervention Trial in Pittsburgh, Pennsylvania, during 1981. The dietary methods may be useful for group data, although differences were found: the food frequency questionnaire produced the highest mean daily estimate (7,876 +/- 569 IU) (mean +/- standard error), the 24-hour recall the intermediate daily estimate (6,944 +/- 602 IU), and the three-day food record the lowest daily estimate (5,137 +/- 470 IU). There was considerable variability between methods in individuals, suggesting that the intake of vitamin A estimated by one dietary method does not predict the intake estimated by another. At the individual level, a low significant correlation (rs = 0.28) occurred between the food frequency questionnaire and the three-day food record methods. Modest agreement in quartile ranking between these two methods indicated that 38% of the individuals fell into the same quartile, 73% into the same +/- one quartile, and 7% into opposite quartiles.