Biological variation in basal metabolic rate and energy metabolism

Biological variation is evident in all aspects of nutrition, particularly total daily energy expenditure (TDEE) and basal metabolic rate (BMR). The impact of ethnicity on biological variation on certain aspects of energy metabolism has been investigated. Predictive equations to estimate BMR were published by the FAOIWHOIUNU (1985) in a report entitled EllerK}' and Protein Requirements. Since its publication, serious concern has been expressed on the validity of these equations, largely because the analysis appears to be based on a biased and incomplete analysis of the world literature on BMR. Using an expanded database (n=10,004) and stringent selection criteria the global BMR data has been re-analysed and new predictive equations presented. The robustness of the new equations were tested by comparing their predictive accuracy with those of existing ones. The BMR of 77 women aged 18-30 years were found to be best described by the newly developed Oxford Brookes equations and the Henry & Rees (1991) equations for tropical peoples (P<0.05 and NS respectively). Furthermore, the new expanded data base was used to plot nonnal curves for BMR for individuals which compared ethnic differences. It was observed that when BMR is expressed per kilogram of body mass, ethnic differences are diminished. The necessity to estimate TDEE in various ethnic groups prompted the evaluation of a non-invasive easy to use technique. Heart rate monitoring as a means of estimating TDEE is reviewed and compares favourably to the use of activity diaries. Whilst highly variable, heart rate monitoring is acknowledged as a valuable tool in the estimation of energy expenditure and activity in individuals and populations Ethnic differences in energy intake in a migrating student population were assessed. Malaysian students recently arrived in the UK were requested to keep food diaries in order to detect changes in their diets. Particular emphasis was placed on changes in the energy densities of food consumed and their effect on body weight and energy balance. After 6 months, it was observed that energy balance was maintained despite the energy density of food consumed in the UK being significantly (P<0.05) more energy dense than food consumed in their native Malaysia. This illustrates the precise way in which the human body can maintain energy balance. Anthropometric differences were compared in 553 individuals from 4 ethnic groups in a study investigating the ann-span and height relationship. Differences were found between the ethnic groups (P<O.OI). The use of ann-span as a proxy for height should be used with caution. It is imperative that more global data collected under strict control is required before human biological variation can be attributed to true ethnic differences and not merely individual variation

Metabolic consequences of obesity and insulin resistance in polycystic ovary syndrome: diagnostic and methodological challenges

AbstractWomen with polycystic ovary syndrome (PCOS) have a considerable risk of metabolic dysfunction. This review aims to present contemporary knowledge on obesity, insulin resistance and PCOS with emphasis on the diagnostic and methodological challenges encountered in research and clinical practice. Variable diagnostic criteria for PCOS and associated phenotypes are frequently published. Targeted searches were conducted to identify all available data concerning the association of obesity and insulin resistance with PCOS up to September 2016. Articles were considered if they were peer reviewed, in English and included women with PCOS. Obesity is more prevalent in women with PCOS, but studies rarely reported accurate assessments of adiposity, nor split the study population by PCOS phenotypes. Many women with PCOS have insulin resistance, though there is considerable variation reported in part due to not distinguishing subgroups known to have an impact on insulin resistance as well as limited methodology to measure insulin resistance. Inflammatory markers are positively correlated with androgen levels, but detailed interactions need to be identified. Weight management is the primary therapy; specific advice to reduce the glycaemic load of the diet and reduce the intake of pro-inflammatory SFA and advanced glycation endproducts have provided promising results. It is important that women with PCOS are educated about their increased risk of metabolic complications in order to make timely and appropriate lifestyle modifications. Furthermore, well-designed robust studies are needed to evaluate the mechanisms behind the improvements observed with dietary interventions.</jats:p

The effect of shift work on the diet of accident and emergency nurses at a general hospital in Malta

Purpose The purpose of this paper was to investigate the effect of shift work on diet and lifestyle in nurses working in the accident and emergency department in a general hospital in Malta. Design/methodology/approach This study was a cross-sectional, quantitative survey, whereby data were collected by the use of anonymous questionnaires consisting of a demographic and anthropometric questionnaire, a lifestyle questionnaire and a food frequency questionnaire to assess dietary intakes. In total, 110 nurses completed the study and were divided into three groups: day nurses, rotating-shift nurses and night-shift nurses. Findings Shift working nurses consumed significantly more energy compared to day nurses (night-shift nurses 1,963 ± 506 kcal; rotating-shift nurses 2,065 ± 655 kcal; day nurses 1,722 ± 486 kcal; p = 0.04). Shift working nurses also consumed more protein (p = 0.04), fat (p = 0.047) and fibre (p = 0.005) compared to day nurses; however, day nurses were the most likely to smoke (p = 0.009). Practical implications Shift work does influence the diet of nurses in Malta. It is recommended that access to healthy food, and time and facilities for physical activity are made available across all working hours and that nurses aim to exercise regularly, eat healthily, quit smoking if necessary and get good-quality sleep where possible. Originality/value In total, 22 per cent of workers in Malta work shifts, and Malta currently has one of the highest rates of obesity in Europe. This study considers the impact of shift work on diet. </jats:sec

The Nutritional Value of Children\u27s Menus in Chain Restaurants in the United Kingdom and Ireland

Objective: Obesity in the United Kingdom and the Republic of Ireland is rising, as is the frequency of eating out in restaurants. The aim of this study was to investigate the nutritional quality of children\u27s menus in restaurants. Design: Cross-sectional review of menus aimed at children from 20 popular chain restaurants in the United Kingdom and Ireland. Main Outcome Measures: Total energy, fat, saturated fat, and salt were collected from every food item on the menu in each restaurant. All potential meal combinations were created. A total of 39,266 meals were analysed. Analysis: Meals were compared with UK nutritional guidelines. Meals from fast food and full-service restaurants and main meals and meal deals were compared. Results: The average meal for younger children (aged 2–5 years) contained 609 ±117 kcal, and for older children (6–12 years) 653 ± 136 kcal compared with guidelines of 364 and 550 kcal, respectively. A total of 68% of younger children\u27s and 55% of older children\u27s meals contained more total fat than recommended and more than 4 times the amount of saturated fat. Fast food restaurant meals contained less energy, fat, and salt than did full-service restaurants, and meal deals were less likely to meet dietary guidelines than were main meals alone. Conclusion and Implications: Eating in chain restaurants, in particular meal deals, does not contribute positively to the diet of children in the United Kingdom and Ireland

Adherence to a gluten free diet is associated with receiving gluten free foods on prescription and understanding food labelling

Treatment of coeliac disease requires a strict gluten-free (GF) diet, however, a high proportion of patients do not adhere to a GF diet. The study explores the practical challenges of a GF diet and dietary adherence in Caucasian and South Asian adults with coeliac disease. Patients with biopsy- and serology-proven coeliac disease were recruited from a hospital database. Participants completed a postal survey (n = 375), including a validated questionnaire designed to measure GF dietary adherence. Half of Caucasians (53%) and South Asians (53%) were adhering to a GF diet. The quarter of patients (n = 97) not receiving GF foods on prescription had a lower GF dietary adherence score compared with those receiving GF foods on prescription (12.5 versus 16.0; p &lt; 0.001). Not understanding food labelling and non-membership of Coeliac UK were also associated with lower GF dietary adherence scores. A higher proportion of South Asian patients, compared with Caucasians, reported difficulties understanding what they can eat (76% versus 5%; p &lt; 0.001) and understanding of food labels (53% versus 4%; p &lt; 0.001). We recommend retaining GF foods on prescription, membership of a coeliac society, and regular consultations with a dietitian to enable better understanding of food labels. Robust studies are urgently needed to evaluate the impact of reducing the amount of GF foods prescribed on adherence to a GF diet in all population groups

Does consuming breakfast influence activity levels? An experiment into the effect of breakfast consumption on eating habits and energy expenditure

Objective: To experimentally compare the effects of eating or skipping breakfast on energy expenditure, activity levels and dietary habits. Design: A randomised cross-over trial, lasting 2 weeks. Participants were provided breakfast during one week and were required to fast until mid-day during the other week. Setting: University campus. Subjects: Forty-nine participants (twenty-six female and twenty-three male participants) were recruited. Food intake was monitored using food diaries, and energy expenditure was assessed using pedometers and heart rate monitors. Morningness–eveningness, physical activity and health were assessed using validated questionnaires. Results: Across all participants, daily energy expenditure did not differ between the two experimental conditions. Total energy intake over 24 h did not vary with condition (male participants: 8134 (SD 447) kJ/d and 7514 (SD 368) kJ/d; female participants: 7778 (SD 410) kJ/d and 7531 (SD 535) kJ/d, for the breakfast and no-breakfast conditions, respectively). However, when comparing habitual breakfast eaters with those with irregular or breakfast-skipping habits, it was found that male non-habitual breakfast eaters consumed significantly (P50?029) more energy during the breakfast condition. Furthermore, female participants who were habitual breakfast eaters were found to eat significantly (P50?005) more and later in the day under the no-breakfast condition. Conclusions: Although the suggestion that breakfast is a behavioural marker for appropriate dietary and physical activity patterns is not refuted by the present findings, our data suggest that the effect of breakfast may vary as a function of gender and morning eating habits, and thus there may be other mechanisms that link BMI and breakfast consumption behaviour

Binge eating behaviours and food cravings in women with Polycystic Ovary Syndrome

Polycystic Ovary Syndrome (PCOS), the most common endocrine condition in women, is often anecdotally associated with binge eating behaviours and food cravings; however there is a paucity of research. This study aimed to report the prevalence of binge eating and food cravings and their relation to obesity risk in women with PCOS. Participants completed an online survey including the Bulimia Investigatory Test, Edinburgh, Food Cravings-Trait Questionnaire and the Three Factor Eating Questionnaire revised-18. The study included obese (n = 340), overweight (n = 70) and lean (n = 45) women with PCOS and lean healthy women (n = 40). Sixty percent of obese women with PCOS were categorised with binge-eating behaviour, with 39% presenting with clinically significant behaviour. Obese women with PCOS presented with high mean food cravings-trait scores (131.6 ± 28.9) that were significantly greater compared with lean (114.0 ± 34.9) and overweight women with PCOS (120.1 ± 29.5; p < 0.001). Multiple regression exploring relations between eating styles and adiposity explained 59% of the variance in binge eating symptom scores in women with PCOS (F = 173.8; p < 0.001, n = 463): significant predictors were food cravings total score (beta = 0.52; p < 0.001), emotional eating score (beta = 0.16; p < 0.001), BMI (beta = 0.13; p < 0.001) and uncontrolled eating score (beta = 0.10; p < 0.01). Compared with lean healthy women, lean women with PCOS exhibited significantly higher binge eating symptom scores (10.9 ± 7.8 versus 7.4 ± 6.0; p < 0.05), though similar total food craving scores (114.0 ± 34.9 versus 105.6 ± 26.6: NS). This study is the largest, to date, to robustly report that a high proportion of women with PCOS exhibit binge eating behaviours. We recommend screening women with PCOS for binge eating behaviours to help inform the choice of weight management approach for this clinical population

Synthesis and characterisation of Li11RE18M4O39−δ: RE = Nd or Sm; M = Al, Co or Fe

Four new phases of general formula, Li11RE18M4O39−δ: REM = NdAl, NdCo, SmCo, SmFe, have been synthesised and characterised. The NdAl phase, and probably the others, is isostructural with the NdFe analogue, but some cation disorder and partial site occupancies prevent full structural refinement of powder neutron diffraction data. The NdCo phase also forms a solid solution with variable Li content (and charge compensation by either oxygen vacancies or variable transition metal oxidation state). The NdAl phase is a modest conductor of Li+ ions whereas the other three phases are electronic conductors, attributed to mixed valence of the transition metal ions. Subsolidus phase diagrams for the systems Li2O–Nd2O3– Al2O3, ‘CoO’ have been determined and an additional new phase, LiCoNd4O8, which appears to have a K2NiF4-related superstructure, identified