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PubMed1998

Control with anorexiant medications.

OBJECTIVE: To show why women are still seeking anorexiant medications despite current concerns over their use. DESIGN: In-depth interviews using grounded theory methodology. SETTING: Participants chose where they were to be interviewed. PARTICIPANTS: Women older than 18 years who had previously taken or were currently taking anorexiant medications for the purpose of losing weight. METHOD: Nine women completed two semistructured in-depth interviews during which they described their experiences from the time they began pharmacologic therapy for obesity until they discontinued the medications. Interview data were compiled and analyzed until saturation was reached. MAIN OUTCOME FINDINGS: Control was an important factor for the women. Their previous lack of control was due to frustration with failed dieting attempts and feeling pressure from others to lose weight. Prescription medications controlled physiologic hunger while the women sought to lose weight. Increased control over hunger and a decrease in weight gave participants confidence to continue their weight-loss efforts without the medications. Once the medications were discontinued, the women were able to maintain weight control through various lifestyle modifications. CONCLUSIONS: Anorexiant medications provide some women with a perception of control that helps them lose weight and not regain it. Health care professionals should be aware of their patients' struggles with weight loss and understand the importance of these medications for some patients.

Adult↗
PubMed2000

Weight estimation in a "deafferented" man and in control subjects: are judgements influenced by peripheral or central signals?

It is not yet certain which sources of information are most important in judging the weight of a held object. In order to study this question further, a "deafferented" man and five controls flexed their wrist to lift a container weighing 1,000 g. Direct vision of the arm and weight was denied; the container's vertical position was displayed to the subjects on an oscilloscope at the start of each trial and, then, in most experimental conditions, this display was removed. The weight was then either gradually increased or decreased over 20 s or left unchanged, on a pseudorandom basis. A verbal judgement of its change was required at the end of each trial, lasting 20 or 40 s. Under these conditions, the "deafferented" subject was unable to correctly judge the weight changes (38% accuracy, n.s. chi2, compared with 77% in control subjects), and even the control subjects, when exposed to muscle vibration, made many errors (54% accuracy). However, in many trials, including those in which the weight was unchanged, the vertical height of the container was not held constant by the subjects, but drifted up or down (mean absolute drift: approximately 2 cm). Hence, the change in muscular activation or stiffness could be estimated by the observers in the majority of trials. This allowed the verbal judgements of both the "deafferented" man and of control subjects undergoing muscle vibration to be correlated with the muscle activation produced, independent of the actual weight being tested. Post-hoc predictions of controls' responses during vibration, based on the direction of the change in muscle activity which these drifts in position implied, were 77% and 66% accurate for +/-750 g and +/-375 g tasks and 73% accurate for forearm-vibration trials (P<0.0001, chi2). Predictions of the "deafferented" subject's responses were 64% accurate (P=0.0002, chi2), even though his own responses were at a chance level with respect to the actual weight change. The judgements made by these subjects might have been based upon a peripheral sensory input, as small afferent fibres are still present in the "deafferented" man and vibration only partly blocked sensory function in the control subjects. Care was taken to minimise all other possible cues to the weight changes, e.g. vestibular, thermal, pressure or pain cues. However, peripheral inputs may not be the only signals used in the subjects' perceptual judgements. They might, instead, be based upon a centrally originating, but illusory changing sense of body position or, possibly, a changing sense of effort. In both cases, a perceived discordance between voluntary muscle activation and body image could underlie the subjects' responses. Our data do not yet allow us to distinguish between these alternative peripheral and central hypotheses, but do highlight the need to include perceptions of body position and motion into judgements of force control.

Case-Control Studies↗
PubMed2001

Modeling face identification processing in children and adults.

Two face identification experiments were carried out to study whether and how children (5-year-olds) and adults integrate single facial features to identify faces. Using the paradigm of the Fuzzy Logical Model of Perception each experiment used the same expanded factorial design, with three levels of eyes variations crossed with three levels of mouth variations as well as their corresponding half-face conditions. In Experiment 1, an integration of facial features was observed in adults only. But, in adjusting the salience of the features varied, the results of Experiment 2 indicate that children and adults evaluated and integrated information from both features to identify a face. A weighted Fuzzy Logical Model of Perception fit the judgments significantly better than a Single Channel Model and questions previous claims of holistic face processing. Although no developmental differences in the stage of the integration of facial information were observable, differences between children and adults appeared in the information used for face identification.

Adult↗
PubMed1992

The perceptions of force and of movement in a man without large myelinated sensory afferents below the neck.

1. Motor memory and the sense of effort have been investigated in a man with a complete large fibre sensory neuropathy for over 16 years. The perceptions of pain, heat, cold and muscular fatigue remained but he was without perceptions of light touch and proprioception below the neck. 2. The subject was able to discriminate weights held in the hand with an accuracy only slightly worse than control subjects (20 g in 200 g) when forearm movement and visual inspection were allowed. With eyes shut however he could only distinguish a weight of 200 g from 400 g. It is concluded that a crude sense of effort remains which may have a peripheral origin. 3. A limited motor memory was also present, which allowed him to maintain a posture or continue a simple repetitive movement. No novel movement was possible without visual feedback. 4. Differences in movement ability between this subject and others with similar if less pure sensory neuropathies are ascribed to rehabilitation.

Adult↗
PubMed1997

Relationship between self-perceived stress and blood pressure.

OBJECTIVE: The importance of stress in the pathogenesis of essential hypertension is controversial. In this study we wanted to evaluate the relation between self-perceived stress and the blood pressure (BP) in a asymptomatic healthy population. SUBJECTS AND METHODS: A total of 1666 guests (mean +/- s.d. age 50 +/- 16 years) attending the air show AIR94 in Buochs, Switzerland volunteered to participate in a cross-sectional study. Using a self-administered questionnaire and visual analogue scales the individual stress perception and other cardiovascular risk behaviours/factors were assessed. BP, body weight, height, and the waist:hip ratio were measured. RESULTS: Individual stress perception was inversely related with the systolic BP (SBP) (r = -0.12, P < 0.001). The relationship was found in both men and women and was independent of age and/or body weight. No relation was found between the diastolic BP (DBP) and stress perception. Subjects with high normal BP according the JNC V classification showed a lower stress perception than did subjects with normal BP. In a multiple regression model the stress score was fourth most predictive of the SBP after body mass index, waist:hip ratio, and age followed by alcohol and fat intake. CONCLUSION: In this study we found an inverse association between the self-perceived stress and SBP. We suggest that the inverse association between BP and the self-perceived stress reflects a neuroendocrine and biochemical setting characterized by inadequate stress handling associated with a higher fat and alcohol intake and more abdominal fat tissue leading to a higher BP. Our data suggest that stress denial in combination with abdominal obesity, alcohol consumption, and smoking may be proxy for a high stress level.

Adult↗
PubMed1976

Impact of social disorganization on behavior, milk yield, and body weight of dairy cows.

To measure the effect of intergroup transfer, four cows were added to a group of 20 cows at 28-day intervals in five trials. The two groups of cows were housed in adjoining lots and fed identical rations from opposite sides of a feed bunk which provided .9 m linear feeding space per cow. Means of the number of agonistic encounters per transferred cow were 9.4, 4.4, 4.3, 3.8, 3.3, and 2.6 during the 1-h period immediately following the first feeding on days 1, 2, 7, 14, 21, and 28. The average dominance values of the transferred cows during the 28 days (.19, .14, and .32) showed no perceptible trend, and mean body weight (567, 569, and 571 kg) was not limited. On day 1 the mean 4% fat-corrected milk yield of the transferred cows decreased .51 kg or 3%, and nontransferred cows increased .01 kg. The decrease in milk yield of the transferred cows was not associated with number of agonistic encounters per se. After day 1 regrouping had no effect on milk yield.

Aggression↗
PubMed2001

Anorexia nervosa and bulimia nervosa: An appraisal.

Anorexia nervosa (AN) and bulimia nervosa (BN) are eating disorders characterized by an aberrant pattern of eating behavior, relentless pursuit of thinness, an intense fear about weight gain and an altered perception of body shape. The pathobiology of eating disorders is complex. Several social, psychological and developmental phenomena are proposed to contribute to the etiology of eating disorders. The role of neuropeptide Y, corticotropin releasing hormone and leptin has also been investigated to understand the pathogenesis of eating disorders. However, most of the neuropeptide alterations noted in eating disorders are secondary to starvation. Several nonpharmacological approaches such as cognitive and behavior-based therapy and interpersonal therapy have been developed to assist weight gain and to modify the behavioral impairment associated with eating disorders. Pharmacotherapy serves as an adjunct in AN, whereas it plays a more significant role in the management of BN. Antidepressants are effective in a limited number of AN patients with comorbid depression. On the other hand, the efficacy of fluoxetine in BN patients in reducing the frequency of binge eating and in the severity of behavioral abnormalities is quite impressive. Several adjunct therapies such as prokinetics and anxiolytics have also been used in AN and BN to assist eating behavior. An insight into genetic and neurochemical abnormalities occurring in eating disorders will help to find better therapeutic agents for these disorders. (c) 2001 Prous Science. All rights reserved.

Journal Article↗
PubMed1989

Perception of eating and exercise in children as a function of child and parent weight status.

The present study assessed the effects of child body weight (obese/lean) and familial loading for obesity (two obese parents/two lean parents) on the psychophysics of sweetness, fatness and exercise workloads, as well as subjective ratings of foods varying in sugar and fat and activities varying in energy expenditure. Children were measured in a baseline state and at 6 months after the obese children had participated in a family-based behavioral weight control program. No differences between obese and lean children in perceptual ratings were observed. However, offspring of obese or lean parents differed on intensity rating, food palatability and activity enjoyment ratings. Intensity ratings for sweetness in offspring of obese parents was increased, with a similar trend for intensity ratings for fatness. Offspring of obese parents rated all foods and activities with lower palatability and enjoyment ratings than offspring of lean parents. After a 6 month family-based behavioral weight loss treatment, obese children had significant decreases in percent overweight while lean children remained stable. Changes in the pattern of food ratings were observed for the obese children, with a reduction in liking for foods high in fat and/or sugar, and an increase in ratings for food slower in fat and sugar. The effects of parental obesity on food and exercise intensity ratings and hedonic ratings were maintained. Overall, these results suggest parental weight influences behavioral factors related to obesity in children.

Body Weight↗
PubMed2001

Sampling and evaluation of specific absorption rates during patient examinations performed on 1.5-Tesla MR systems.

It was the purpose of present study, to evaluate a large number of exposure-time courses measured during patient examinations in clinical routine in relation to the current IEC standard and the draft version of the revised standard and, moreover, to investigate whether there is a correlation between the subjective heat perception of the patients during the MR examination and the intensity of RF power deposition. To this end, radiofrequency exposure to 591 patients undergoing MR examinations performed on 1.5-Tesla MR systems was monitored in five clinics and evaluated in accordance with both IEC standards. For each of the 7902 sequences applied, whole body and partial body SARs were estimated on the basis of a simple patient model. Following the examinations, 149 patients were willing to provide information in a questionnaire regarding their body weight and their subjective heat perception during the examination. Although patient masses entered into the MR system were in some cases too high, reliable masses could be estimated by the SAR monitor. In relation to our data, the revision of the IEC standard results in a tightening of the restrictions, but still more than 96% of the examinations did not exceed the SAR limits recommended for the normal operating mode. For the exposure conditions examined, no statistically significant correlation was found between the subjective heat perception of the patients and the intensity of power deposition. Taking advantage of the possibility to compute running SAR averages, MR sequences can be employed in clinical practice for which SAR levels exceed the defined IEC limits, if the acquisition time is short in relation to the averaging period and energy deposition has been low previous to the applied high-power sequence.

Female↗
PubMed2005

Cardiovascular risk factors and risk behaviors in railway workers. Professional stress and cardiovascular risk.

UNLABELLED: The research considers the hypothesis that stressful professions, such as engine driver, influence the morbidity and mortality through cardiovascular diseases and favour some harmful habits with an impact upon cardiovascular morbidity. METHODS: There were selected for study 496 engine drivers, males, and a control group of 305 males. They were questioned about: name, address, family history, pathological personal history, alcohol intake, smoking, diet habits, physical activity, sleeping hours and stress perception. There were measured: height, weight, blood pressure. There were determined: fasting plasma glucose, cholesterol, triglycerides, HDL-cholesterol and LDL-cholesterol. RESULTS: Hypertension was registered in 23.5% of the engine drivers and in only 9.5% the control group (P<0.05). Dyslipidemia was noted in 57.4% of the engine drivers and 52.45% of the control group. Prevalence of smoking and overweight was higher in the control group. Unhealthy dietary patterns and physical inactivity were present in both groups, the circadian rhythms were altered only for engine drivers and questionnaires for stress perception showed higher irritability in the control group. CONCLUSIONS: The prevalence of some risk factors is higher for engine drivers, but for the others it is not. Also it seems that professional stress favours some harmful habits such as tobacco smoking, but the control group smokes more and they are inactive individuals with a great amount of irritability. The results do not totally sustain the idea we started from, that engine driver is a stressful profession; it seems that the effort/reward imbalance is more important than job-demand itself.

Adult↗
PubMed2006

Correlates of self-induced vomiting and laxative misuse in a community sample of women.

The correlates of self-induced vomiting and laxative misuse were examined in a large community sample of young adult women (N = 5255). Scores on measures of eating disorder psychopathology, general psychological distress, functional impairment, as well as the use of health services for an eating or weight problem were compared among participants who reported regular self-induced vomiting, but not laxative misuse (N = 59), and those who reported regular misuse of laxatives, but not vomiting (N = 39). Individuals who misused laxatives were older, perceived poorer physical health, and were less likely to have sought treatment specifically for a problem with eating than those who engaged in self-induced vomiting. In all other respects, the groups were similar. However, individuals who regularly engaged in both forms of purging (N = 8) had particularly high levels of eating disorder and comorbid psychopathology. The perception among women of normal weight that only syndromes involving the use of self-induced vomiting constitute an eating disorder may need to be addressed in prevention programs. The combination of self-induced vomiting and laxative misuse may indicate a particularly severe psychiatric disturbance.

Adolescent↗
PubMed2001

Why don't low-income mothers worry about their preschoolers being overweight?

CONTEXT: Mothers are in an important position to prevent obesity in their children by shaping early diet and activity patterns. However, many mothers of overweight preschool children are not worried about their child's weight. OBJECTIVE: To explore mothers' perceptions about how they determine when a child is overweight, why children become overweight, and what barriers exist to preventing or managing childhood obesity. DESIGN: Three focus groups with 6 participants in each. Participant comments were transcribed and analyzed. Themes were coded independently by the 6 authors who then agreed on common themes. SETTING: A clinic of the Special Supplemental Nutrition Program for Women, Infants, and Children in Cincinnati, Ohio. PARTICIPANTS: Eighteen low-income mothers (13 black, 5 white) of preschool children (mean age of 44 months) who were at-risk for later obesity. All but 1 mother had a body mass index (BMI) >/=25 kg/m(2), and 12 mothers had a BMI >/=30 kg/m(2). All but 1 child had a BMI >/=85th percentile for age and sex, and 7 had a BMI >/=95th percentile. Results. Mothers did not define overweight or obese in their children according to how height and weight measurements were plotted on the standard growth charts used by health professionals. Instead, mothers were more likely to consider being teased about weight or developing limitations in physical activity as indicators of their child being overweight. Children were not believed to be overweight if they were active and had a healthy diet and/or a good appetite. Mothers described overweight children as thick or solid. Mothers believed that an inherited tendency to be overweight was likely to be expressed in the child regardless of environmental factors. In trying to shape their children's eating, mothers believed that their control over the child's diet was challenged by other family members. If a child was hungry, despite having just eaten, it was emotionally difficult for mothers to deny additional food. CONCLUSIONS: Health professionals should not assume that defining overweight according to the growth charts has meaning for all mothers. Despite differing perceptions between mothers and health professionals about the definition of overweight, both groups agree that children should be physically active and have healthy diets. Health professionals may be more effective in preventing childhood obesity by focusing on these goals that they share with mothers, rather than on labeling children as overweight.

Adult↗
PubMed1993

Effects of stereoscopic and rotational displays in a three-dimensional path-tracing task.

A series of three experiments investigated the effectiveness of stereoscopic and rotational display techniques for the purpose of establishing human factors guidelines for the design of three-dimensional (3D) displays. In the described experiments, depth perception was evaluated by examining accuracy in a 3D path-tracing task, with stimulus displays resembling the structure of cerebral angiograms. The first experiment allowed subjects to control rotation in dynamic displays. The results indicated that performance improved using either technique relative to viewing two-dimensional (2D) displays. However, rotational displays were superior to stereoscopic displays, and performance was best when both techniques were combined. The second experiment compared subject-controlled rotation with observation of continuously rotating displays at different rates of rotation. Performance declined at faster rotation rates; however, there were no advantages of subject-controlled rotation. In the third experiment, performance in rotational displays was no better than that in stereoscopic displays enhanced with multiple static viewing angles. However, performance was always best when both 3D techniques were jointly implemented. The results are discussed in terms of the visual information available using either 3D display technique and are related to the weighted additive model of depth perception.

Adult↗
PubMed2003

Body image of adolescents in a multi-ethnic Caribbean population.

OBJECTIVE: To examine the perceptions of body size among adolescents in Trinidad and to determine whether there were ethnic differences. DESIGN: Cross-sectional survey. SETTING: Secondary schools in Trinidad. SUBJECTS: A stratified random sample of 1139 adolescents, aged 14-17 y. MEASUREMENTS: Silhouettes of different body sizes were used to determine perceptions of body size, while weights and heights were measured to determine actual body size. RESULTS: A total of 1090 students (96% response rate) participated, comprising 578 (53%) females. The main ethnic groups were South Asian (49%), African (25%) and persons of mixed ethnicity (23%). The calculated body mass index (BMI) indicated that 14% were thin, 73% normal and 13% overweight; however there was a preponderance of thinness among South Asian males (28%). Whereas 68% of students correctly identified their body size, South Asian males were also more likely to overestimate their body size than the other adolescents, ie they were thinner than they thought. Overall, 64% of the sample was satisfied with their current size, but thin South Asians were more likely to be satisfied with their size than other thin adolescents (P=0.04), while overweight Africans were more likely to be satisfied than other overweight persons (P=0.03). The majority of the sample associated the normal body size with good health, but the majority also associated the overweight and obese silhouettes with wealth. In addition, 40% of them associated the male overweight and obese silhouettes with happiness. CONCLUSION: Although the prevalence of overweight/obesity was not high, the perception of the Trinidadian adolescent that obesity was associated with wealth, and to a lesser extent happiness, and the satisfaction of the overweight African females with their size, were all causes for concern.

Adolescent↗
PubMed2004

The backpack load in schoolchildren: clinical and social importance, and efficacy of a community-based educational intervention. A prospective controlled cohort study.

AIM: The aims of this paper were: to establish the efficacy of an educational intervention in reducing school backpack weight and, possibly, back pain; to verify the content of backpacks and the social importance of the problem; to confirm existing data in the literature. METHODS DESIGN: controlled prospective educational intervention. SETTING: community. PARTICIPANTS: the entire Year 6 population (402 pupils) of 2 randomly chosen rural school districts of the province of Mantua (Italy); of these, we took 108 (selected according to position in the class register): 82.4% completed the study; 402 parents and 124 teachers entered the study, 77.1% and 37.1% respectively completed it. INTERVENTION: instructive meeting and written material for teachers, and a leaflet for parents on backpack management. MAIN OUTCOME MEASURES: backpack weight and content; back pain; subjective perceptions of backpack load; packing and carrying methods; backpack load: importance, management and education; backpack characteristics. RESULTS: We obtained a statistically significant reduction in the backpack weight in each of the groups (study 11.2%; control 7.9% - not a statistically significant difference); 90.1% of the material carried is necessary. Backpacks are considered a problem by 95.1% of parents, 73% of teachers, and 60.3% of pupils. Backpack weight: 8.75+/-1.26 kg (19.9+/-5.3% of body weight); fatigue during backpack carrying: 72.7%; back pain life prevalence: 58.4%; fatigue during backpack carrying and considering backpacks a problem were associated with back pain (odds ratios 4.4 and 5). CONCLUSIONS: Educational intervention is not the answer to the problem and solutions, like the clear legal limits established for adults, need to be found.

Journal Article↗
PubMed1999

The surface-weight illusion: on the contribution of grip force to perceived heaviness.

Previous psychophysical studies have shown that an object, lifted with a precision grip, is perceived as being heavier when its surface is smooth than when it is rough. Three experiments were conducted to assess whether this surface-weight illusion increases with object weight, as a simple fusion model suggests. Experiment 1 verified that grip force increases more steeply with object weight for smooth objects than for rough ones. In Experiment 2, subjects rated the weight of smooth and rough objects. Smooth objects were judged to be heavier than rough ones; however, this effect did not increase with object weight. Experiment 3 employed a different psychophysical method and replicated this additive effect, which argues strongly against the simple fusion model. The whole pattern of results is consistent with a weighted fusion model in which the sensation of grip force contributes only partially to the perceived heaviness of a lifted object.

Adult↗