C.L. Lawton

Comparison of high-fat and high-carbohydrate foods in a meal or snack on short-term fat and energy intakes in obese women.

The present study aimed to compare the action of high-fat and high-carbohydrate (CHO) foods on meal size (satiation) and post-meal satiety in obese women. A within-subjects design was used; each participant received all four nutritional challenges. Fifteen healthy obese women (age 21-56 years, BMI 35-48 kg/m2) participated; thirteen completed all four test days. On two test days, participants were exposed to a nutritional challenge comprising an ad libitum high-fat or high-CHO lunch. On the other two test days they were exposed to a challenge comprising an ad libitum sweet high-fat or high-CHO mid-afternoon snack. Energy and macronutrient intakes were measured at each eating episode. Visual analogue rating scales were completed periodically to record subjective feelings of appetite. When offered a high-CHO selection of foods at lunch and mid-afternoon participants consumed less energy than when offered a high-fat selection. However, post-meal satiety was similar. Total test-day energy intake was significantly higher when high-fat foods were consumed at lunch, but not as a snack. Consumption of high-fat foods at a lunch and snack increased the amount of fat consumed over the whole test day. In conclusion, energy intake of an eating episode was influenced by nutrient composition in this group of obese women. Consumption of high-fat foods at lunch or as a snack led to overconsumption relative to high-CHO foods. However, high-fat foods at meals may have greater potential to influence daily intake than at snacks, probably because meals are larger eating episodes and therefore give greater opportunity to overconsume.

Correspondence of continuous interstitial glucose measurement against arterialised and capillary glucose following an oral glucose tolerance test in healthy volunteers.

The aim of the present study was to validate the Glucoday continuous interstitial ambulatory glucose-monitoring device (AGD) against plasma glucose measured from arterialised venous (AV) and glucose from capillary whole blood (finger prick, FP) in non-diabetic subjects in response to an oral glucose tolerance test. Fifteen healthy overweight men (age 30-49 years, BMI 26-31 kg/m2) participated. Glucose levels were measured before, during and after consumption of an oral 75 g glucose load using twelve FP samples and forty-four 1 ml AV blood samples during 180 min. Interstitial glucose was measured via the AGD. Three venous samples for fasting insulin were taken to estimate insulin resistance. Profiles of AGD, AV and FP glucose were generated for each participant. Glucose values for each minute of the measurement period were interpolated using a locally weighted scatterplot smoother. Data were compared using Bland-Altman plots that showed good correspondence between all pairs of measurements. Concordance between the three methods was 0.8771 (Kendalls W, n 15, P < 0.001). Concordance was greater between AV and FP (W = 0.9696) than AGD and AV (W = 0.8770) or AGD and FP (W = 0.8764). Analysis of time to peak glucose indicated that AGD measures lagged approximately 15 min behind FP and AV measures. Percent body fat was significantly correlated with time to peak glucose levels for each measure, while BMI and estimated insulin resistance (homeostatic model assessment, HOMA) were not. In conclusion, AGD shows good correspondence with FP and AV glucose measures in response to a glucose load with a 15 min time lag. Taking this into account, AGD has potential application in nutrition and behaviour studies.

The influence of the glycaemic index of an evening meal on the glycaemic response to breakfast and subsequent cognitive performance in young adults

It has been reported that the glycaemic response to consumption of a high glycaemic index (GI) breakfast is higher after consuming a high GI evening meal compared to a low GI evening meal. However, no research has investigated how this ‘previous meal effect’ may influence cognitive performance. Eight young, healthy, male participants consumed a low GI and a high GI evening meal, in a counterbalanced order. In each condition, the following morning a high GI breakfast was consumed. Immediate recall, delayed recall, recognition, and attention were assessed before and after breakfast, and blood glucose was measured throughout. The blood glucose profiles following each meal were not significantly different between the high and low GI meals. However, there was an association between evening and morning glycaemic responses, with higher evening glycaemic responses being associated with higher morning glycaemic responses. Generally, there were no associations between GI and cognitive performance or between morning glycaemic response and cognitive performance. In conclusion, the glycaemic response to an evening meal can influence the glycaemic response to breakfast. This has implications for research investigating any associations between blood glucose, nutritional manipulations, and cognitive performance.

S54 Cognitive function in adults with and without cystic fibrosis related diabetes (CFRD) attending a large UK cystic fibrosis unit

Introduction and objectives On reaching adulthood many cystic fibrosis (CF) sufferers develop cystic fibrosis related diabetes (CFRD). CFRD shares clinical characteristics with type 1 (T1DM) and type 2 diabetes mellitus (T2DM). Impaired glucose tolerance (IGT), T1DM and T2DM have deleterious effects on cognitive performance. Hence, patients with CFRD are hypothesised to show similar impairment. This study aimed to elucidate the nature and severity of any cognitive impairment in patients with CFRD compared to non-diabetic patients with CF and healthy controls matched as closely as possible for age, gender and education level. Patients with CF were also matched as closely as possible on CFTR genotype. Methods Adult (>16 years old), pancreatic insufficient patients registered to a large UK CF unit who had adequate verbal and written English were eligible. 49 patients with insulin-treated CFRD and 49 CF non-diabetics who had received a normal oral glucose tolerance test (OGTT) within the past 12 months were recruited. 46 healthy matched controls were recruited from relatives of patients and the general population. Cognitive performance was assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB). Subjective measures of sleep, stress, mood and cognitive functioning were also collected. Results Matched controls performed better than both groups of patients with CF on tests of visual memory and learning, verbal memory, visual sustained attention, processing speed and executive function. Patients with CFRD performed significantly worse than controls on tests of mental flexibility and processing speed, which is consistent with the pattern of impairment shown in T1DM, and on verbal memory and learning, which is consistent with the pattern of impairment shown in T2DM. Compared to non-diabetic patients with CF, those with CFRD performed worse on tests of visual sustained attention, verbal memory, working memory, and processing speed. Conclusion CFRD has a negative impact on cognitive performance akin to T1DM and T2DM. Non-diabetic patients with CF also show impaired cognition but to a lesser degree than CFRD. Even modest cognitive impairment in adults with CF may impact upon their self-management skills, health and quality of life.

295 Cognition in adult patients with cystic fibrosis (CF) with and without cystic fibrosis related diabetes (CFRD)

Objectives Impaired glucose tolerance (IGT), type 1 (T1DM) and type 2 diabetes mellitus (T2DM) have deleterious effects on cognitive performance. Hence, patients with cystic fibrosis related diabetes (CFRD) are hypothesized to show similar impairment. This study aimed to elucidate the nature and severity of any cognitive impairment in patients with CFRD compared to non-diabetic patients with CF and healthy controls matched as closely as possible for age, gender and education level. Patients with CF were also matched as closely as possible on CFTR genotype. Methods Adult (>16 years old), pancreatic insufficient patients registered to the Leeds CF Unit who had adequate verbal and written English were eligible. To date, 45 patients with insulin-treated CFRD and 47 non-diabetics who had received a normal oral glucose tolerance test (OGTT) within the past 12 months were included. 10 healthy controls were recruited to date from relatives of patients and the general population. Cognitive performance was assessed using the Cambridge Neuropsychological Test Automated Battery (CANTAB). Results Preliminary findings show that matched controls perform better than both groups of patients with CF on tests of visual memory and learning, verbal memory, visual sustained attention and executive function. Patients with CFRD performed worse than controls on tests of mental flexibility and visual sustained attention, which is consistent with the pattern of impairment shown in T1DM, and on verbal memory, which is consistent with the pattern of impairment shown in T2DM. Conclusion Like T1DM and T2DM, CFRD may have a negative impact on cognitive performance and needs to be explored.

Psychological benefits of weight loss: a systematic research review

Introduction: It is generally accepted that weight loss has significant physiological benefits, such as reduced risk of diabetes, lowered blood pressure and blood lipid levels. However, few behavioural and dietary interventions have investigated psychological benefit as the primary outcome. Method: Systematic review methodology was adopted to evaluate the psychological outcomes of weight loss following participation in a behavioural and/or dietary weight loss intervention in overweight/obese populations. 35 studies were selected for inclusion and were reviewed. Results: Changes in self-esteem, depressive symptoms, body image and health related quality of life (HRQoL) were evaluated and discussed.The results demonstrated consistent improvements in psychological outcomes concurrent with and sometimes without weight loss. Improvements in body image and HRQoL (especially vitality) were closely related to changes in weight. Conclusion: Although the quality of the studies reviewed was generally acceptable, only 8 out of 35 studies included a suitable control/comparison group and the content, duration of intervention and measures used to assess psychological outcomes varied considerably. Further research is required to improve the quality of studies assessing the benefits of weight loss to fully elucidate the relationship between weight loss and psychological outcomes.Introduction: The role of the workplace as an opportunity for improving health has been highlighted in recent reports. The East Midlands Platform for Health and Wellbeing is a network of private, public and voluntary sector organisations working to improve health and reduce obesity. Member organisations commit to undertake actions to improve health and wellbeing of employees, individuals and/or communities. As part of Slimming World’s commitment, this pilot assessed the merits of providing weight management support via the workplace at two large regional employers. Methods: 278 British Gas and Nottingham University Hospitals NHS Trust employees were offered 12 weeks’ support at either a bespoke workplace group or established community-based Slimming World group. Weight change was recorded weekly. Dietary and physical activity behaviours, along with aspects of psychological health were assessed by questionnaire pre and post-programme. Results: 121 employees (meeting inclusion criteria) joined a workplace-based group and 114 a community-based group. Weight and attendance: Mean joining BMI was 32.4kg/m2. 138 (59%) participants completed the programme (attended within final 4 weeks).Behaviour changes: Participants who completed both questionnaires (n=87), reported positive changes in dietary and physical activity behaviours (all p<.001) (figure 1), and psychological health (mental wellbeing, self-worth and self-esteem, all p<0.05). There were no significant differences between worksite and community intervention groups for any outcomes. Conclusion: Providing weight management support via the workplace significantly reduced weight of participants (-3.9%). Completer analysis also revealed positive changes in healthy eating habits and activity levels, and also importantly psychological health, which may impact on working life. The Slimming World programme works effectively within both the work setting and via community-based provision when employees are recruited via the workplace.