Validation of the Mobile App Version of the EQ-5D-5L Quality of Life Questionnaire Against the Gold Standard Paper-Based Version: Randomized Crossover Study

Background

Study participants and patients often perceive (long) questionnaires as burdensome. In addition, paper-based questionnaires are prone to errors such as (unintentionally) skipping questions or filling in a wrong type of answer. Such errors can be prevented with the emergence of mobile questionnaire apps.

Objective

This study aimed to validate an innovative way to measure the quality of life using a mobile app based on the EQ-5D-5L questionnaire. This validation study compared the EQ-5D-5L questionnaire requested by a mobile app with the gold standard paper-based version of the EQ-5D-5L.

Methods

This was a randomized, crossover, and open study. The main criteria for participation were participants should be aged ≥18 years, healthy at their own discretion, in possession of a smartphone with at least Android version 4.1 or higher or iOS version 9 or higher, digitally skilled in downloading the mobile app, and able to read and answer questionnaires in Dutch. Participants were recruited by a market research company that divided them into 2 groups balanced for age, gender, and education. Each participant received a digital version of the EQ-5D-5L questionnaire via a mobile app and the EQ-5D-5L paper-based questionnaire by postal mail. In the mobile app, participants received, for 5 consecutive days, 1 question in the morning and 1 question in the afternoon; as such, all questions were asked twice (at time point 1 [App T1] and time point 2 [App T2]). The primary outcomes were the correlations between the answers (scores) of each EQ-5D-5L question answered via the mobile app compared with the paper-based questionnaire to assess convergent validity.

Results

A total of 255 participants (healthy at their own discretion), 117 (45.9%) men and 138 (54.1%) women in the age range of 18 to 64 years, completed the study. To ensure randomization, the measured demographics were checked and compared between groups. To compare the results of the electronic and paper-based questionnaires, polychoric correlation analysis was performed. All questions showed a high correlation (0.64-0.92; P<.001) between the paper-based and the mobile app–based questions at App T1 and App T2. The scores and their variance remained similar over the questionnaires, indicating no clear difference in the answer tendency. In addition, the correlation between the 2 app-based questionnaires was high (>0.73; P<.001), illustrating a high test-retest reliability, indicating it to be a reliable replacement for the paper-based questionnaire.

Conclusions

This study indicates that the mobile app is a valid tool for measuring the quality of life and is as reliable as the paper-based version of the EQ-5D-5L, while reducing the response burden.

Effects of a 13-Week Personalized Lifestyle Intervention Based on the Diabetes Subtype for People with Newly Diagnosed Type 2 Diabetes

A type 2 diabetes mellitus (T2DM) subtyping method that determines the T2DM phenotype based on an extended oral glucose tolerance test is proposed. It assigns participants to one of seven subtypes according to their β-cell function and the presence of hepatic and/or muscle insulin resistance. The effectiveness of this subtyping approach and subsequent personalized lifestyle treatment in ameliorating T2DM was assessed in a primary care setting. Sixty participants, newly diagnosed with (pre)diabetes type 2 and not taking diabetes medication, completed the intervention. Retrospectively collected data of 60 people with T2DM from usual care were used as controls. Bodyweight (p < 0.01) and HbA1c (p < 0.01) were significantly reduced after 13 weeks in the intervention group, but not in the usual care group. The intervention group achieved 75.0% diabetes remission after 13 weeks (fasting glucose ≤ 6.9 mmol/L and HbA1c < 6.5% (48 mmol/mol)); for the usual care group, this was 22.0%. Lasting (two years) remission was especially achieved in subgroups with isolated hepatic insulin resistance. Our study shows that a personalized diagnosis and lifestyle intervention for T2DM in a primary care setting may be more effective in improving T2DM-related parameters than usual care, with long-term effects seen especially in subgroups with hepatic insulin resistance.

Stakeholder Perspectives on Barriers and Facilitators for the Adoption of Virtual Clinical Trials: Qualitative Study

Background

Conventional clinical trials are essential for generating high-quality evidence by measuring the efficacy of interventions in rigorously controlled clinical environments. However, their execution can be expensive and time-consuming. In addition, clinical trials face several logistical challenges regarding the identification, recruitment, and retention of participants; consistent data collection during trials; and adequate patient follow-up. This might lead to inefficient resource utilization. In order to partially address the current problems with conventional clinical trials, there exists the need for innovations. One such innovation is the virtual clinical trial (VCT). VCTs allow for the collection and integration of diverse data from multiple information sources, such as electronic health records, clinical and demographic data, patient-reported outcomes, anthropometric and activity measurements, and data collected by digital biomarkers or (small) samples that participants can collect themselves. Although VCTs have the potential to provide substantial value to clinical research and patients because they can lower clinical trial costs, increase the volume of data collected from patients’ daily environment, and reduce the burden of patient participation, so far VCT adoption is not commonplace.

Objective

This paper aims to better understand the barriers and facilitators to VCT adoption by determining the factors that influence individuals’ considerations regarding VCTs from the perspective of various stakeholders.

Methods

Based on online semistructured interviews, a qualitative study was conducted with pharmaceutical companies, food and health organizations, and an applied research organization in Europe. Data were thematically analyzed using Rogers’ diffusion of innovation theory.

Results

A total of 16 individuals with interest and experience in VCTs were interviewed, including persons from pharmaceutical companies (n=6), food and health organizations (n=4), and a research organization (n=6). Key barriers included a potentially low degree of acceptance by regulatory authorities, technical issues (standardization, validation, and data storage), compliance and adherence, and lack of knowledge or comprehension regarding the opportunities VCTs have to offer. Involvement of regulators in development processes, stakeholder exposure to the results of pilot studies, and clear and simple instructions and assistance for patients were considered key facilitators.

Conclusions

Collaboration among all stakeholders in VCT development is crucial to increase knowledge and awareness. Organizations should invest in accurate data collection technologies, and compliance of patients in VCTs needs to be ensured. Multicriteria decision analysis can help determine if a VCT is a preferred option by stakeholders. The findings of this study can be a good starting point to accelerate the development and widespread implementation of VCTs.

The Effect of a Lifestyle Intervention on Type 2 Diabetes Pathophysiology and Remission: The Stevenshof Pilot Study

Although lifestyle interventions can lead to diabetes remission, it is unclear to what extent type 2 diabetes (T2D) remission alters or improves the underlying pathophysiology of the disease. Here, we assess the effects of a lifestyle intervention on T2D reversal or remission and the effects on the underlying pathology. In a Dutch primary care setting, 15 adults with an average T2D duration of 13.4 years who were (pharmacologically) treated for T2D received a diabetes subtyping ("diabetyping") lifestyle intervention (DLI) for six months, aiming for T2D remission. T2D subtype was determined based on an OGTT. Insulin and sulphonylurea (SU) derivative treatment could be terminated for all participants. Body weight, waist/hip ratio, triglyceride levels, HbA1c, fasting, and 2h glucose were significantly improved after three and six months of intervention. Remission and reversal were achieved in two and three participants, respectively. Indices of insulin resistance and beta cell capacity improved, but never reached healthy values, resulting in unchanged T2D subtypes. Our study implies that achieving diabetes remission in individuals with a longer T2D duration is possible, but underlying pathology is only minimally affected, possibly due to an impaired beta cell function. Thus, even when T2D remission is achieved, patients need to continue adhering to lifestyle therapy.

Effect of an Enriched Protein Drink on Muscle Mass and Glycemic Control during Combined Lifestyle Intervention in Older Adults with Obesity and Type 2 Diabetes: A Double-Blind RCT

Background: Weight loss is key to treatment of older adults with obesity and type 2 diabetes, but also a risk for muscle mass loss. This study investigated whether a whey protein drink enriched with leucine and vitamin D could preserve muscle mass and improve glycemic control during combined lifestyle intervention in this population. Methods: 123 older adults with obesity and type 2 diabetes were randomized into a 13-week lifestyle intervention with dietary advice and exercise, receiving either the enriched protein drink (test) or an isocaloric control (control). Muscle mass was assessed with dual-energy X-ray absorptiometry and glycemic control by oral glucose tolerance test. Statistical analyses were performed using a linear mixed model. Results: There was a nonsignificant increase in leg muscle mass (+0.28 kg; 95% CI, −0.01 to 0.56) and a significant increase in appendicular muscle mass (+0.36 kg; 95% CI, 0.005 to 0.71) and total lean mass (+0.92 kg; 95% CI, 0.19 to 1.65) in test vs. control. Insulin sensitivity (Matsuda index) also increased in test vs. control (+0.52; 95% CI, 0.07 to 0.97). Conclusions: Use of an enriched protein drink during combined lifestyle intervention shows beneficial effects on muscle mass and glycemic control in older adults with obesity and type 2 diabetes.

Obese Older Type 2 Diabetes Mellitus Patients with Muscle Insulin Resistance Benefit from an Enriched Protein Drink during Combined Lifestyle Intervention: The PROBE Study

(1) Background: Recent research showed that subtypes of patients with type 2 diabetes may differ in response to lifestyle interventions based on their organ-specific insulin resistance (IR). (2) Methods: 123 Subjects with type 2 diabetes were randomized into 13-week lifestyle intervention, receiving either an enriched protein drink (protein+) or an isocaloric control drink (control). Before and after the intervention, anthropometrical and physiological data was collected. An oral glucose tolerance test was used to calculate indices representing organ insulin resistance (muscle, liver, and adipose tissue) and β-cell functioning. In 82 study-compliant subjects (per-protocol), we retrospectively examined the intervention effect in patients with muscle IR (MIR, n = 42) and without MIR (no-MIR, n = 40). (3) Results: Only in patients from the MIR subgroup that received protein+ drink, fasting plasma glucose and insulin, whole body, liver and adipose IR, and appendicular skeletal muscle mass improved versus control. Lifestyle intervention improved body weight and fat mass in both subgroups. Furthermore, for the MIR subgroup decreased systolic blood pressure and increased VO2peak and for the no-MIR subgroup, a decreased 2-h glucose concentration was found. (4) Conclusions: Enriched protein drink during combined lifestyle intervention seems to be especially effective on increasing muscle mass and improving insulin resistance in obese older, type 2 diabetes patients with muscle IR.

Evaluation of Food-Intake Behavior in a Healthy Population: Personalized vs. One-Size-Fits-All

In public health initiatives, generic nutrition advice (GNA) from national guidelines has a limited effect on food-intake improvement. Personalized nutrition advice (PNA) may enable dietary behavior change. A monocentric, randomized, parallel, controlled clinical trial was performed in males (n = 55) and females (n = 100) aged 25 to 70 years. Participants were allocated to control, GNA or PNA groups. The PNA group consisted of automatically generated dietary advice based on personal metabolic health parameters, dietary intake, anthropometric and hemodynamic measures, gender and age. Participants who received PNA (n = 51) improved their nutritional intake status for fruits P (p < 0.0001), whole grains (p = 0.008), unsalted nuts (p < 0.0001), fish (p = 0.0003), sugar-sweetened beverages (p = 0.005), added salt (p = 0.003) and less unhealthy choices (p = 0.002), whereas no improvements were observed in the control and GNA group. PNA participants were encouraged to set a goal for one or multiple food categories. Goal-setting led to greater improvement of food categories within the PNA group including; unsalted nuts (p < 0.0001), fruits (p = 0.0001), whole grains (p = 0.005), fish (p = 0.0001), dairy (p = 0.007), vegetables (p = 0.01) and unhealthy choices (p = 0.02). In a healthy population, participants receiving PNA changed their food-intake behavior more favorably than participants receiving GNA or no advice. When personal goals were set, nutritional behavior was more prone to change.

The possibilities of the use of N-of-1 and do-it-yourself trials in nutritional research

Background

N-of-1 designs gain popularity in nutritional research because of the improving technological possibilities, practical applicability and promise of increased accuracy and sensitivity, especially in the field of personalized nutrition. This move asks for a search of applicable statistical methods.

Objective

To demonstrate the differences of three popular statistical methods in analyzing treatment effects of data obtained in N-of-1 designs.

Method

We compare Individual-participant data meta-analysis, frequentist and Bayesian linear mixed effect models using a simulation experiment. Furthermore, we demonstrate the merits of the Bayesian model including prior information by analyzing data of an empirical study on weight loss.

Results

The linear mixed effect models are to be preferred over the meta-analysis method, since the individual effects are estimated more accurately as evidenced by the lower errors, especially with lower sample sizes. Differences between Bayesian and frequentist mixed models were found to be small, indicating that they will lead to the same results without including an informative prior.

Conclusion

For empirical data, the Bayesian mixed model allows the inclusion of prior knowledge and gives potential for population based and personalized inference.

Subjective feelings of appetite of wholegrain breakfasts evaluated under controlled, laboratory and 'at home' conditions

BACKGROUND

Appetite regulating properties of foods are usually investigated under laboratory conditions, whereas in real life, foods are consumed under at home conditions. The objective of this study was to compare the acute effects of breakfasts when tested in a laboratory condition and in an at home condition. Appetite regulating properties of two bread breakfasts and two cereal breakfasts were also compared.

SUBJECTS AND METHODS

In this randomized cross-over trial balanced for laboratory and at home test conditions, thirty-two women consumed five breakfasts, i.e. two bread breakfasts, two cereal breakfasts and one fried-egg breakfast. Visual analogue scales for measuring appetite were captured via an on-line scoring system and were analyzed as incremental area under the curve, as satiation phase and as satiety phase.

RESULTS

Location effects were limited to two small effects only. An overall location effect in hunger feelings was observed (p = 0.040), which occurred specifically during the short satiation period (p = 0.0002) where hunger feelings scored higher under laboratory conditions. Similarly, a location effect was observed for desire to eat (p = 0.001); this was again higher under laboratory conditions. No other location effects were observed. Bread breakfasts did not differ in their appetite regulating properties. The Steel Cut oatmeal breakfast was reported to be more satiating (p = 0.001) as compared to the ready-to-eat cereal.

CONCLUSIONS

Whereas the five breakfasts varied somewhat in their appetite regulating properties, evaluation under laboratory conditions overall did not result in different appetite scores compared to the at home conditions. This suggests that at home testing may be a useful alternative to laboratory test conditions for nutrition research.

Effect of Caffeine on Attention and Alertness Measured in a Home-Setting, Using Web-Based Cognition Tests

BACKGROUND

There is an increasing interest among nutritional researchers to perform lifestyle and nutritional intervention studies in a home setting instead of testing subjects in a clinical unit. The term used in other disciplines is 'ecological validity' stressing a realistic situation. This becomes more and more feasible because devices and self-tests that enable such studies are more commonly available. Here, we present such a study in which we reproduced the effect of caffeine on attention and alertness in an at-home setting.

OBJECTIVE

The study was aimed to reproduce the effect of caffeine on attention and alertness using a Web-based study environment of subjects, at home, performing different Web-based cognition tests.

METHODS

The study was designed as a randomized, placebo-controlled, double-blind, crossover study. Subjects were provided with coffee sachets (2 with and 2 without caffeine). They were also provided with a written instruction of the test days. Healthy volunteers consumed a cup of coffee after an overnight fast. Each intervention was repeated once. Before and 1 hour after coffee consumption subjects performed Web-based cognitive performance tests at home, which measured alertness and attention, established by 3 computerized tests provided by QuantifiedMind. Each test was performed for 5 minutes.

RESULTS

Web-based recruitment was fast and efficient. Within 2 weeks, 102 subjects applied, of whom 70 were eligible. Of the 66 subjects who started the study, 53 completed all 4 test sessions (80%), indicating that they were able to perform the do it yourself tests, at home, correctly. The Go-No Go cognition test performed at home showed the same significant improvement in reaction time with caffeine as found in controlled studies in a metabolic ward (P=.02). For coding and N-back the second block was performed approximately 10% faster. No effect was seen on correctness.

CONCLUSIONS

The study showed that the effects of caffeine consumption on a cognition test in an at-home setting revealed similar results as in a controlled setting. The Go-No Go test applied showed improved results after caffeine intake, similar as seen in clinical trials. This type of study is a fast, reliable, economical, and easy way to demonstrate effectiveness of a supplement and is rapidly becoming a viable alternative for the classical randomized control trial to evaluate life style and nutritional interventions.

TRIAL REGISTRATION

Clinicaltrials.gov NCT02061982; https://clinicaltrials.gov/ct2/show/NCT02061982 (Archived by WebCite at https://clinicaltrials.gov/ct2/show/NCT02061982).

Microdosing of a Carbon-14 Labeled Protein in Healthy Volunteers Accurately Predicts Its Pharmacokinetics at Therapeutic Dosages

Preclinical development of new biological entities (NBEs), such as human protein therapeutics, requires considerable expenditure of time and costs. Poor prediction of pharmacokinetics in humans further reduces net efficiency. In this study, we show for the first time that pharmacokinetic data of NBEs in humans can be successfully obtained early in the drug development process by the use of microdosing in a small group of healthy subjects combined with ultrasensitive accelerator mass spectrometry (AMS). After only minimal preclinical testing, we performed a first-in-human phase 0/phase 1 trial with a human recombinant therapeutic protein (RESCuing Alkaline Phosphatase, human recombinant placental alkaline phosphatase [hRESCAP]) to assess its safety and kinetics. Pharmacokinetic analysis showed dose linearity from microdose (53 μg) [(14) C]-hRESCAP to therapeutic doses (up to 5.3 mg) of the protein in healthy volunteers. This study demonstrates the value of a microdosing approach in a very small cohort for accelerating the clinical development of NBEs.

Dietary medium chain fatty acid supplementation leads to reduced VLDL lipolysis and uptake rates in comparison to linoleic acid supplementation

Dietary medium chain fatty acids (MCFA) and linoleic acid follow different metabolic routes, and linoleic acid activates PPAR receptors. Both these mechanisms may modify lipoprotein and fatty acid metabolism after dietary intervention. Our objective was to investigate how dietary MCFA and linoleic acid supplementation and body fat distribution affect the fasting lipoprotein subclass profile, lipoprotein kinetics, and postprandial fatty acid kinetics. In a randomized double blind cross-over trial, 12 male subjects (age 51±7 years; BMI 28.5±0.8 kg/m²), were divided into 2 groups according to waist-hip ratio. They were supplemented with 60 grams/day MCFA (mainly C8:0, C10:0) or linoleic acid for three weeks, with a wash-out period of six weeks in between. Lipoprotein subclasses were measured using HPLC. Lipoprotein and fatty acid metabolism were studied using a combination of several stable isotope tracers. Lipoprotein and tracer data were analyzed using computational modeling. Lipoprotein subclass concentrations in the VLDL and LDL range were significantly higher after MCFA than after linoleic acid intervention. In addition, LDL subclass concentrations were higher in lower body obese individuals. Differences in VLDL metabolism were found to occur in lipoprotein lipolysis and uptake, not production; MCFAs were elongated intensively, in contrast to linoleic acid. Dietary MCFA supplementation led to a less favorable lipoprotein profile than linoleic acid supplementation. These differences were not due to elevated VLDL production, but rather to lower lipolysis and uptake rates.

Nutrigenomics approach elucidates health-promoting effects of high vegetable intake in lean and obese men

We aimed to explore whether vegetable consumption according to guidelines has beneficial health effects determined with classical biomarkers and nutrigenomics technologies. Fifteen lean (age 36 ± 7 years; BMI 23.4 ± 1.7 kg m⁻²) and 17 obese (age 40 ± 6 years; BMI 30.3 ± 2.4 kg m⁻²) men consumed 50- or 200-g vegetables for 4 weeks in a randomized, crossover trial. Afterward, all subjects underwent 4 weeks of energy restriction (60 % of normal energy intake). Despite the limited weight loss of 1.7 ± 2.4 kg for the lean and 2.1 ± 1.9 kg for the obese due to energy restriction, beneficial health effects were found, including lower total cholesterol, LDL cholesterol and HbA1c concentrations. The high vegetable intake resulted in increased levels of plasma amino acid metabolites, decreased levels of 9-HODE and prostaglandin D3 and decreased levels of ASAT and ALP compared to low vegetable intake. Adipose tissue gene expression changes in response to vegetable intake were identified, and sets of selected genes were submitted to network analysis. The network of inflammation genes illustrated a central role for NFkB in (adipose tissue) modulation of inflammation by increased vegetable intake, in lean as well as obese subjects. In obese subjects, high vegetable intake also resulted in changes related to energy metabolism, adhesion and inflammation. By inclusion of sensitive omics technologies and comparing the changes induced by high vegetable intake with changes induced by energy restriction, it has been shown that part of vegetables’ health benefits are mediated by changes in energy metabolism, inflammatory processes and oxidative stress.

Effect of body fat distribution on the transcription response to dietary fat interventions

Combination of decreased energy expenditure and increased food intake results in fat accumulation either in the abdominal site (upper body obesity, UBO) or on the hips (lower body obesity, LBO). In this study, we used microarray gene expression profiling of adipose tissue biopsies to investigate the effect of body fat distribution on the physiological response to two dietary fat interventions. Mildly obese UBO and LBO male subjects (n = 12, waist-to-hip ratio range 0.93–1.12) were subjected to consumption of diets containing predominantly either long-chain fatty acids (PUFA) or medium-chain fatty acids (MCT). The results revealed (1) a large variation in transcription response to MCT and PUFA diets between UBO and LBO subjects, (2) higher sensitivity of UBO subjects to MCT/PUFA dietary intervention and (3) the upregulation of immune and apoptotic pathways and downregulation of metabolic pathways (oxidative, lipid, carbohydrate and amino acid metabolism) in UBO subjects when consuming MCT compared with PUFA diet. In conclusion, we report that despite the recommendation of MCT-based diet for improving obesity phenotype, this diet may have adverse effect on inflammatory and metabolic status of UBO subjects. The body fat distribution is, therefore, an important parameter to consider when providing personalized dietary recommendation.

Short-term fatty acid intervention elicits differential gene expression responses in adipose tissue from lean and overweight men

The goal of this study was to investigate the effect of a short-term nutritional intervention on gene expression in adipose tissue from lean and overweight subjects. Gene expression profiles were measured after consumption of an intervention spread (increased levels of polyunsaturated fatty acids, conjugated linoleic acid and medium chain triglycerides) and a control spread (40 g of fat daily) for 9 days. Adipose tissue gene expression profiles of lean and overweight subjects were distinctly different, mainly with respect to defense response and metabolism. The intervention resulted in lower expression of genes related to energy metabolism in lean subjects, whereas expression of inflammatory genes was down-regulated and expression of lipid metabolism genes was up-regulated in the majority of overweight subjects. Individual responses in overweight subjects were variable and these correlated better to waist–hip ratio and fat percentage than BMI.

The effect of Korean pine nut oil on in vitro CCK release, on appetite sensations and on gut hormones in post-menopausal overweight women

Appetite suppressants may be one strategy in the fight against obesity. This study evaluated whether Korean pine nut free fatty acids (FFA) and triglycerides (TG) work as an appetite suppressant. Korean pine nut FFA were evaluated in STC-1 cell culture for their ability to increase cholecystokinin (CCK-8) secretion vs. several other dietary fatty acids from Italian stone pine nut fatty acids, oleic acid, linoleic acid, alpha-linolenic acid, and capric acid used as a control. At 50 μM concentration, Korean pine nut FFA produced the greatest amount of CCK-8 release (493 pg/ml) relative to the other fatty acids and control (46 pg/ml). A randomized, placebo-controlled, double-blind cross-over trial including 18 overweight post-menopausal women was performed. Subjects received capsules with 3 g Korean pine (Pinus koraiensis) nut FFA, 3 g pine nut TG or 3 g placebo (olive oil) in combination with a light breakfast. At 0, 30, 60, 90, 120, 180 and 240 minutes the gut hormones cholecystokinin (CCK-8), glucagon like peptide-1 (GLP-1), peptide YY (PYY) and ghrelin, and appetite sensations were measured. A wash-out period of one week separated each intervention day.

CCK-8 was higher 30 min after pine nut FFA and 60 min after pine nut TG when compared to placebo (p < 0.01). GLP-1 was higher 60 min after pine nut FFA compared to placebo (p < 0.01). Over a period of 4 hours the total amount of plasma CCK-8 was 60% higher after pine nut FFA and 22% higher after pine nut TG than after placebo (p < 0.01). For GLP-1 this difference was 25% after pine nut FFA (P < 0.05). Ghrelin and PYY levels were not different between groups. The appetite sensation "prospective food intake" was 36% lower after pine nut FFA relative to placebo (P < 0.05).

This study suggests that Korean pine nut may work as an appetite suppressant through an increasing effect on satiety hormones and a reduced prospective food intake.

Dietary supplementation of different doses of NUTRIOSE FB, a fermentable dextrin, alters the activity of faecal enzymes in healthy men

BACKGROUND

It is well documented that fermentation of carbohydrates that escape digestion exert several effects supposed to be beneficial for (colonic) health, including an increase in stool volume, a shorter intestinal transit time, production of short chain fatty acids and a decrease of colonic pH (Kritchevsky 1988). NUTRIOSE FB is a dextrin that is not completely hydrolysed and absorbed in the small intestine, due to many alpha-1.6 linkages and the presence of non-digestible glucoside linkages (e. g. alpha-1.2 and alpha-1.3). To be beneficial for 'colonic' health effective NUTRIOSE FB must reach the cecum in some form.

AIM OF THE STUDY

To estimate how much non digested NUTRIOSE FB is fermented and to determine the fibre-like effect of the wheat dextrin NUTRIOSE((R))FB by analysing enzymatic activity in faeces.

METHODS

In a randomized, double-blind,multiple dose, placebo-controlled, combined cross-over and parallel trial, 20 healthy men (age 31.7 +/- 9.1 yrs; BMI 24.5 +/- 2.9 kg.m(-2) received different treatments. One group of ten subjects consumed on top of their diet 10, 30 and 60 g daily of NUTRIOSE FB or maltodextrin (placebo). The other group of 10 subjects consumed 15, 45 and 80 g daily. Each dose was consumed for 7 days. On the last two days of each of the 7-day period, faeces were collected in which the enzymatic activity and NUTRIOSE FB residue were analysed.

RESULTS

As expected, the faecal residue of NUTRIOSE FB non-linearly increased with the dose of NUTRIOSE FB to approximately 13% of 80 g/d. Compared with the placebo, 30, 45, 60 and 80 g/d of NUTRIOSE FB increased the concentration of alpha-glucosidase significantly. All daily doses of NUTRIOSE FB (10 g/d to 80 g/d) led to significant changes in concentration of beta-glucosidase.

CONCLUSIONS

The small amount of the residue of NUTRIOSE FB in the faeces suggests that approximately 87% or more of NUTRIOSE FB is digested or fermented in the gastrointestinal tract. Fermentation of NUTRIOSE FB led to an increased faecal concentration of alpha- and beta-glucosidase.

Short-term digestive tolerance of different doses of NUTRIOSE FB, a food dextrin, in adult men

OBJECTIVE

To determine the tolerance of increasing dosages of an incompletely hydrolysed and/or incompletely absorbed food dextrin coming from wheat starch, NUTRIOSE FB, at daily levels of 10 and 15 g up to 60 and 80 g, respectively.

DESIGN

A randomized, double-blind, multiple dose, placebo-controlled, combined crossover and parallel trial.

SETTING

The metabolic ward of TNO Nutrition and Food Research.

SUBJECTS

A total of 20 healthy men (age 31.7 +/- 9.1 y; BMI 24.5 +/- 2.9 kg/m2).

INTERVENTION

One group of 10 subjects consumed on top of their diet 10, 30 and 60 g of NUTRIOSE FB or maltodextrin (placebo) daily. The other group of 10 subjects consumed 15, 45 and 80 g daily. Each dose was consumed for 7 days.

RESULTS

Compared with placebo, flatulence occurred more frequently over the last 6 days on 30, 60 or 80 g/day of NUTRIOSE FB (P < 0.05). During the last 24 h, that is, days 6-7, of 60 and 80 g/day of NUTRIOSE FB, the frequency of flatulence was even higher (P < 0.05). During the last 24 h on a daily dose of 60 g NUTRIOSE FB, the frequency of defecation decreased (P < 0.05). Bloating occurred more often during the last 24 h on 80 g/day of NUTRIOSE FB (P < 0.05). None of the doses of NUTRIOSE FB resulted in diarrhoea. Compared to baseline levels, breath H2 excretion, which was only measured after a week with 10 and 15 g of NUTRIOSE FB daily, increased (P < 0.05). However, no difference in area under the curve was found.

CONCLUSIONS

NUTRIOSE FB is a fermentable carbohydrate and is well tolerated up to a dose of 45 g daily. Higher daily dosages (60 and 80 g) may result in flatulence, but does not result in diarrhoea.

SPONSORSHIP

TNO Nutrition and Food Research was assigned by Roquette Frères to perform the study.

Effect of two breakfasts, different in carbohydrate composition, on hunger and satiety and mood in healthy men

OBJECTIVE

To study the effect of simple vs complex carbohydrates (SCHO and CCHO respectively) containing breakfasts on blood parameters, hunger and satiety and mood.

DESIGN

A 2-day, open, randomised, cross-over trial.

SUBJECTS

A total of 26 male subjects (34+/-6 y; BMI 23.4+/-2.2 kg m(-2)).

MEASUREMENTS

Blood glucose, insulin, triacylglycerols (TG), free fatty acids (FFA) and cholecystokinin (CCK) were determined repeatedly for 4 h on both test days after a breakfast containing SCHO or CCHO. Feelings of hunger and satiety were determined at similar time points as well. Mood state was examined 3 h after breakfast consumption.

RESULTS

Consumption of a SCHO breakfast resulted in higher glucose and insulin levels at 30 min after breakfast consumption. TG at 180 min, and FFA at 180 and 240 min were higher after SCHO breakfast than after CCHO breakfast. Satiety scores were higher after CCHO breakfast consumption for the first 90 min after intake. Furthermore, the item 'fatigue' was scored higher after SCHO breakfast than after CCHO breakfast intake.

CONCLUSION

Consumption of a CCHO breakfast is favourable in comparison to a SCHO breakfast, because of the lower perception of 'fatigue' and the higher degree of satiety after consumption.

Effects of sugar intake on body weight: a review

Weight reduction programmes are mainly focused on reducing intake of fat and sugar. In this review we have evaluated whether the replacement of dietary (added) sugar by low-energy sweeteners or complex carbohydrates contributes to weight reduction. In two experimental studies, no short-term differences in weight loss were observed after use of aspartame as compared to sugar in obese subjects following a controlled energy-restricted diet. However, consumption of aspartame was associated with improved weight maintenance after a year. In two short-term studies in which energy intake was not restricted, substitution of sucrose by artificial sweeteners, investigated mostly in beverages, resulted in lower energy intake and lower body weight. Similarly, two short-term studies, comparing the effect of sucrose and starch on weight loss in obese subjects did not find differences when the total energy intake was equal and reduced. An ad libitum diet with complex carbohydrates resulted in lower energy intake compared to high-sugar diets. In two out of three studies, this was reflected in lower body weight in subjects consuming the complex carbohydrate diet. In conclusion, a limited number of relatively short-term studies suggest that replacing (added) sugar by low-energy sweeteners or by complex carbohydrates in an ad libitum diet might result in lower energy intake and reduced body weight. In the long term, this might be beneficial for weight maintenance. However, the number of studies is small and overall conclusions, in particular for the long term, cannot be drawn.

Contribution of caffeine to the homocysteine-raising effect of coffee: a randomized controlled trial in humans

BACKGROUND

A high plasma total homocysteine concentration is associated with increased risk of cardiovascular disease. Consumption of unfiltered or filtered coffee raises total homocysteine concentrations in healthy volunteers. The responsible compound, however, is unknown.

OBJECTIVE

The objective was to determine whether caffeine explains the homocysteine-raising effect of coffee.

DESIGN

Forty-eight subjects aged 19-65 y completed this randomized crossover study with 3 treatments, each lasting 2 wk. Subjects consumed 6 capsules providing 870 mg caffeine/d (test treatment), 0.9 L paper-filtered coffee providing approximately 870 mg caffeine/d, or 6 placebo capsules. Blood samples were drawn fasting and 4 h after consumption of 0.45 L coffee or 3 capsules.

RESULTS

The mean fasting plasma homocysteine concentration after the placebo treatment was 9.6 +/- 3.1 micro mol/L. The caffeine and coffee treatments increased fasting homocysteine by 0.4 micro mol/L (95% CI: 0.1, 0.7; P = 0.04), or 5%, and by 0.9 micro mol/L (95% CI: 0.6, 1.2; P = 0.0001), or 11%, respectively, compared with placebo. The increase in homocysteine concentrations 4 h after consumption of 0.45 L coffee relative to consumption of 3 placebo capsules was 19% (P = 0.0001). Caffeine treatment had a much weaker acute effect on homocysteine (4%; P = 0.09). Effects of caffeine were stronger in women than in men, but the effects of coffee did not differ significantly between men and women.

CONCLUSIONS

Caffeine is partly responsible for the homocysteine-raising effect of coffee. Coffee, but not caffeine, affects homocysteine metabolism within hours after intake, although the effect is still substantial after an overnight fast.

A model for regulation of the Mg(2+)-stimulated acto-myosin-ATPase activity: inhibition of the formation of actin-myosin complex and the Mg( 2+)-stimulated acto-myosin-ATPase activity by IMP and AMP

Previously, we showed that the decrease in force output during continuous isometric contractions in rat skeletal muscle was related to an increase in the concentration of IMP. In this paper we report on additional experiments in which the effect of IMP on the Mg(2+)-stimulated acto-myosin-ATPase activity of isolated actin and myosin is measured at 35 degrees C. The results show that 1) the binding of actin to myosin is co-operative (Hill coefficient = 3.82); 2) in the presence of IMP or AMP the Mg(2+)-stimulated acto-myosin-ATPase activity is inhibited up to 60% at 10 mM; 3) in the presence of IMP or AMP not only the Mg(2+)-stimulated acto-myosin-ATPase activity decreases, but also K(50). From these results we conclude that IMP and AMP may be considered as uncompetitive inhibitors. Our results suggest that IMP and AMP can prevent an 'energy crisis' during exhaustive exercise of short duration by down-regulating the contractile machinery.

The effect of body weight changes and endurance training on 24h substrate oxidation

OBJECTIVE

To investigate the effect of exercise training and dietary macronutrient composition on 24 h substrate oxidation in male, obese subjects.

DESIGN

A 16 month exercise intervention study was executed, including a weight loss period with a very low energy diet (VLED) for 2 months at the start of the study.

SUBJECTS

Twelve male, obese subjects (age 36.3+/-5.1 y; body weight 94.6+/-13.9 kg; body mass index, BMI 30.8+/-3.0 kg/m2) and in an additional study 15 lean, well-trained subjects (age 36.2+/-7.2 y; body weight 72.2+/-5.9 kg; BMI 22.3+/-1.7 kg/m2) participated.

MEASUREMENTS

Substrate oxidation was measured during a standardized 36 h stay in the respiration chamber at the start of the study (0 months), and at 4, 10 and 16 months. In the respiration chamber subjects were randomly assigned to a high-fat (Hi.F) diet (60% of energy (En%) fat) or a reduced-fat (Red.F) diet (30 En% fat). The well-trained group was measured once in the respiration chamber for 36 h according to the same protocol.

RESULTS

At any time point, independent of the diet consumed, the 24 h carbohydrate (CHO) balances in the chamber were mostly negative (means ranging from +31 to -98 g/d) and the fat balances mostly positive (means ranging from -26 to +38 g/d) for the obese a well as for the lean, well-trained group. For both diets an increased shortage of 70 g of CHO was found at 16 months compared with 4 months, and an increase in fat balance of 33 g during the same time period in the obese subjects, indicating that CHO oxidation had increased with 12 months endurance training. In the well-trained group the 24h CHO balance was even more negative for both types of diet (-103 to -185 g/d for the Red.F and Hi.F diet, respectively) under similar conditions compared with the trained obese group.

CONCLUSION

The changes in 24 h substrate utilization in the obese, as well as in the well-trained group, suggest that endurance training increased the reliance on carbohydrate oxidation and therefore did not increase 24 fat oxidation.

Predictors of weight maintenance

OBJECTIVE

To obtain predictors of weight maintenance after a weight-loss intervention.

RESEARCH METHODS AND PROCEDURES

An overall analysis of data from two-long intervention studies [n=67 women; age: 37.9+/-1.0 years; body weight (BW): 87.0+/-1.2 kg; body mass index: 32.1+/-0.5 kg.m(-2); % body fat: 42.4+/-0.5%]. Subjects were measured before a very low energy diet (month 0), after the very low energy diet of 2 months (month 2) and after a 14-month follow-up phase (at 16 months), in which fiber or a carbohydrate-containing food supplement was supplied. The baseline measurements and the changes in parameters induced by the diet intervention were used to predict the changes in BW in the follow-up phase [deltaBW(2-16)].

RESULTS

Multiple regression analysis revealed that 50% (p<0.001) of the variability in weight regain could be explained by physiological and behavioral factors. These were: frequency of previous dieting (r2=0.27, p<0.05), hunger score (measured with the three-factor eating behavior questionnaire), and change in 24-hour resting metabolic rate (RMR). Frequent dieters showed significantly more weight regain than less frequent dieters (8.8+/-1.0 kg vs. 5.1+/-0.8 kg, p<0.01). Subjects having parents with obesity regained almost significantly more weight than subjects with lean parents (8.5+/-0.2 kg vs. 5.1+/-1.5 kg, respectively; p = 0.06).

DISCUSSION

Physiological (deltaRMR-24 hours) and behavioral factors (previous frequency of dieting and hunger score) predicted failure of weight maintenance and, as such, can be used to identify women who are at risk for weight regain.

Effect of exercise training on long-term weight maintenance in weight-reduced men

This study investigated whether endurance training is effective for successful long-term weight maintenance after weight reduction. Fifteen male obese subjects (age, 37.3+/-5.2 years; body weight [BW], 96.2+/-13.6 kg; body mass index [BMI], 30.9+/-2.8 kg x m(-2)) participated in a 16-month exercise-intervention study. During the first 4 months, all subjects trained three to four times weekly, consuming a very-low-energy diet (VLED) during the first 2 months. After the 4-month treatment period, seven subjects continued training for 12 months (3 to 4 times per week). The other eight subjects served as a control group not involved in a training program. The regain (increase during the intervention period as a percentage of the 4-month treatment) of BW at 16 months was 64% (+/-26%) for the whole group (trained v. control, 52%+/-28% v. 74%+/-20%, P = .09). The increase in absolute fat mass (FM) was significantly lower at 16 months for the trained group (trained v. control, 4.8+/-1.9 v. 9.0+/-3.3 kg), as was the regain of FM at 16 months (trained v. control, 61%+/-24% v. 92%+/-32%, P = .05). The amount of regain of the waist circumference, waist to hip ratio (WHR), and sagittal diameter were correlated with the amount of training (hours) performed weekly (deltawaist, r = -.55, P<.05; deltaWHR, r = -.50, P = .06; deltasagittal diameter, r = -.53, P<.05). Physical fitness parameters (maximal power output [Wmax] and oxygen uptake [Vo2 max]) were significantly increased in both groups at 4 months. Trained subjects maintained high levels of physical fitness at 16 months, in contrast to the control group. In conclusion, although BW regain was not significantly different between the groups, trained subjects showed less regain of FM and higher levels of physical fitness, factors related to a lower risk for cardiovascular disease (CVD), compared with the control group. Furthermore, the regain of FM, which occurred even in the exercising group with a relatively intensive training program, suggests that maintenance of fat loss is extremely difficult.

The effect of exercise training on leptin levels in obese males

The effect of endurance training on plasma leptin levels was investigated in 15 obese male subjects (age 37.3 +/- 5.2 yr, body weight 96.5 +/- 13.6 kg, and body mass index 29.8 +/- 3.0 kg/m2) in a weight loss and exercise program. After 4 mo of treatment consisting of a very low energy diet (VLED) and endurance exercise training (3-4 times weekly, 1 h sessions, moderate intensity), two groups were formed. One group continued the exercise sessions (trained subjects, n = 7) and the other group stopped with the exercise program (control, n = 8). Measurements of anthropometry, aerobic power, and fasted blood samples were executed at fixed time points (0, 2, 4, 10, and 16 mo). With partial regression analysis, keeping the changes in insulin and body fat percentage constant, it was shown that the number of hours of exercise training was significantly correlated with changes in leptin levels, during the 16-mo period (r = 0.56, P < 0.05). Changes in insulin levels were significantly related to the changes in leptin levels (r = 0.47, P < 0.05), which were less for changes in body fat percentage (r = 0.42, P = 0.07). During the VLED, the change in insulin concentration affected leptin levels significantly (r = 0.79) but changes in body fat percentage were not noted. It is concluded that endurance exercise training decreased plasma leptin levels independently of changes in plasma insulin levels and body fat percentage.

The effectiveness of long-term supplementation of carbohydrate, chromium, fibre and caffeine on weight maintenance

OBJECTIVE

To investigate whether supplementation of carbohydrate, chromium, dietary fibre and caffeine is effective for maintenance of weight-loss in the long-term.

DESIGN

A longitudinal, double-blind, randomly assigned intervention study of 16 months with supplementation of either 50g of carbohydrates (CHO), 200 micrograms chromium-picolinate (Cr-Pic), 20g of soluble fibre plus 100 mg caffeine (CHO+) or 50g of plain CHO, for 16 months besides a very low energy diet (VLED) during the first two months.

SUBJECTS

Thirty-three female obese subjects (age, 34.8 +/- 7.0 y; body weight (BW): 85.5 +/- 10.0 kg; body mass index (BMI) 31.2 +/- 3.7 kg.m-2) participated, 13 subjects were supplemented with CHO+, 11 subjects were supplemented with CHO and 9 subjects served as a control group.

MEASUREMENTS

SW, body composition, energy intake and blood parameters were measured before the VLED (0), after the VLED at 2 months (2), and at 4, 10 and 16 months.

RESULTS

The amount and course of relapse of BW was equal for the supplemented and control groups. The average regain at 16 months (the weight gained as a percentage of the total weight loss during the VLED) was 66.1 +/- 81.2%, and was not different between the groups. No differences in body composition were found between the groups at 16 months. The CHO supplements resulted in significantly elevated energy percentage (En %) intake of CHO daily, in both supplemented groups, although this did not result in less regain. Pearson correlation analysis for all subjects revealed that the more fat consumed, the more regain was found at 16 months (r = 0.41, P < 0.05). A high CHO consumption was correlated with less regain (r = -0.40, P = 0.05). Furthermore, chromium intake did not result in significant changes in blood parameters and body composition.

CONCLUSION

Although additional supplementation of CHO, chromium, dietary fibre and caffeine intake did not affect BW, the En % CHO daily was increased significantly. Our results indicate that a high En% intake of CHO and a low En% intake of fat daily is beneficial for prevention of weight regain.

Effect of one week of fibre supplementation on hunger and satiety ratings and energy intake

The effect of one week of supplementation with a water-soluble fibre (guar gum) was studied in obese women who had lost weight. In study 1 (N=17; mean+/-SEM: age 38.5+/-2.3 yrs; weight 86.8+/-2.3 kg; BMI 32.2+/-0.9 kg.m-2) energy intake and hunger and satiety scores were assessed under free-living conditions. In study 2 (N=14; age 44. 5+/-1.8 yrs; weight 78.8+/-3.1 kg; BMI 29.0+/-0.9 kg.m-2) energy intake was fixed at 6 MJ.day-1 (their normal energy intake at that time) or 4 MJ.day-1 (low energy intake). In both studies, the effect of one week of fibre supplementation (40 g in study 1 and 20 g in study 2) was compared with no supplementation. In study 1, mean energy intake decreased significantly from 6.7+/-0.4 MJ to 5.4+/-0.2 MJ daily after fibre supplementation, while hunger and satiety scores did not change. At a low energy intake level of 4 MJ given in study 2, hunger scores were significantly decreased after fibre supplementation. No changes were seen in hunger and satiety scores during fibre supplementation at 6 MJ. The reduction in energy intake by soluble fibre under free living conditions and the hunger-reducing effect of fibre at the low energy intake level (4 MJ) suggests that fibre may be useful in the treatment of obesity, by facilitating compliance to low energy intake.

The effectiveness of long-term fibre supplementation on weight maintenance in weight-reduced women

OBJECTIVE

To investigate whether fibre supplementation is effective in weight-reduced subjects for maintenance of weight-loss in the long-term.

DESIGN

Longitudinal, randomly assigned intervention study with supplementation of 20 g of water soluble fibre (guar gum) daily for 14 months after an energy-restricted period of two months (VLCD).

SUBJECTS

Thirty-one female, obese subjects (age: 41.4 +/- 7.4 y: BMI 33.2 +/- 3.7 kg/m-2); 20 subjects were supplemented with fibre and 11 subjects served as the control group.

MEASUREMENTS

Body weight (BW), blood lipids and blood pressure, anthropometry, and eating behaviour were measured before the VLCD (0), after VLCD (2), and at 4, 10, and 16 months.

RESULTS

The fibre group with at least 80% compliance (group A) and the control group showed the same weight regain response after VLCD. The fibre consuming group with 50-80% compliance (group B) differed with respect to relapse. The rate and amount of BW regain was significantly higher for group B. After 14 months group B had returned to baseline levels, whereas group A and the control group showed a tendency to a lower BW than at baseline (P = 0.09). No effect of fibre supplementation was found on blood lipids, blood pressure and energy intake. Eating behaviour characteristics changed during the intervention and might explain differences in weight maintenance.

CONCLUSIONS

No effect of 14 months fibre supplementation was found on weight maintenance in weight-reduced subjects. Guar gum intake did not result in reduction of blood pressure or cholesterol, or in suppression of energy intake.

Energy intake adaptation of food intake to extreme energy densities of food by obese and non-obese women

OBJECTIVE

Examination of energy intake in relation to energy density of food in obese and non-obese women. Assessment of energy and macronutrient intake over a day.

DESIGN

Controlled food intake diaries of two weekdays and one weekend day.

SETTING

Daily life, with visits to the department of Human Biology, State University of Limburg.

SUBJECTS

96 women: 68 subjects: 34 obese and 34 non-obese were matched for age (20-50y) and were selected based on completing the food intake diaries accurately, i.e. underreporting < 10% of their estimated energy intake.

RESULTS

The obese women showed a food intake distribution of 24 en% (0-7.5 kJ/g), 52 en% (7.5-15 kJ/g) and 24 en% (15-22.5 kJ/g), with a macronutrient composition of C/P/F: 39/17/44 en%. (Significantly different from the values of non-obese (P = 0.007) and of the Dutch food guidelines values (P = 0.008)). Non-obese women showed a food intake distribution of 38 en% (0-7.5 kJ/g), 49 en% (7.5-15 kJ/g), 13 en% (15-22.5 kJ/g), with a macronutrient composition of C/P/F: 46/17/37 en%. Energy intake per meal increased from 1.2 or 1.3 MJ to 4.1 or 4.5 MJ over a day.

CONCLUSIONS

In obese women food intake was adapted to extreme energy densities of the food and in non-obese women food intake was overadapted to extreme energy densities. Energy intake per meal increased during the day.

The effect of different dosages of caffeine on endurance performance time

The effect of different dosages of caffeine (0-5-9-13 mg.kg body weight-1) on endurance performance was examined. Nine well-trained cyclists participated in this study (VO2max 65.1 +/- 2.6 ml.kg-1.min-1). Caffeine capsules were administered in random order and double-blind. One hour after capsule ingestion, subjects cycled until exhaustion at 80% Wmax on an electromagnetically braked cycle ergometer. Blood samples were taken before, during and after the exercise test. Before and after the test a urine sample was obtained. A significant increase in endurance performance was found for all caffeine tests compared to placebo (endurance time 47 +/- 13, 58 +/- 11, 59 +/- 12 and 58 +/- 12 min for 0, 5, 9 and 13 mg.kg-1 body weight, respectively). No differences were found in endurance performance between the three caffeine dosages which indicates that no dose-response relation of caffeine and endurance performance was found. An increased free fatty acid and glycerol concentration was found after caffeine consumption compared with placebo. The mean urinary caffeine concentrations after exercise were 4.8 +/- 1.8, 8.9 +/- 5.2 and 14.9 +/- 6.9 micrograms.ml-1 urine for 5, 9 and 13 mg of caffeine.kg-1 body weight. Only the lowest dose of caffeine resulted in urine caffeine concentrations below the doping limit of the International Olympic Committee of 12 micrograms.ml-1 urine in all individuals. It is concluded that caffeine is an ergogenic aid that stimulates endurance performance. A dose-response relation between caffeine and endurance time was not found for the dose-range investigated.(ABSTRACT TRUNCATED AT 250 WORDS)