PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Weight Perception”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1979

Effect of thumb anaesthesia on weight perception, muscle activity and the stretch reflex in man.

1. We have confirmed the results of Gandevia & McCloskey (1977) on the effect of thumb anaesthesia on perception of weights lifted by the thumb. Weights lifted by flexion feel heavier and weights lifted by extension feel lighter. 2. The change in size of the long-latency stretch reflex in flexor pollicis longus or extensor pollicis longus after thumb anaesthesia cannot explain the effect on weight perception by removal or augmentation of the background servo assistance to muscular contraction. 3. During smooth thumb flexion, thumb anaesthesia increases e.m.g. activity in flexor pollicis longus and extensor pollicis longus for any given opposing torque. 4. During smooth thumb extension the opposite occurs: e.m.g. activity in both extensor and flexor pollicis longus decreases. 5. Clamping the thumb at the proximal phalanx to limit movement solely to the interphalangeal joint reduces or abolishes the effect of anaesthesia on both weight perception and e.m.g. activity during both flexion or extension tasks. 6. Gandevia & McCloskey's findings on the distorting effects of thumb anaesthesia on weight perception cannot be used to support the hypothesis of an efferent monitoring system of the sense of effort. Our results emphasize the close functional relationship between cutaneous and joint afferent information and motor control.

Anesthesia, Local↗
PubMed1991

Body-weight perceptions and selected weight-management goals and practices of high school students--United States, 1990.

Among adults, overweight is associated with elevated serum cholesterol levels, elevated blood pressure, and noninsulin-dependent diabetes and is an independent risk factor for coronary heart disease. Youth who are overweight and remain overweight as adults may increase their risk for certain chronic diseases in adulthood. However, overemphasis on thinness during adolescence may contribute to potentially harmful weight-management practices and eating disorders such as anorexia nervosa and bulimia nervosa. This report presents self-reported body-weight perceptions and selected weight-management goals and practices among high school students in the United States.

Adolescent↗
PubMed1988

Gender differences in body weight perception and weight-loss strategies of college students.

Gender differences in college students' perceptions and satisfaction with body weight were examined. Females tended to perceive themselves as overweight when they were not, failed to see themselves as underweight when they were, and many of those who did not see themselves as even slightly overweight wanted to lose weight. Although males reported some dissatisfaction with their bodies, they tended to want to gain rather than lose weight. Females dieted more frequently than did males, and nearly one-third of the females reported either self-induced vomiting or laxative use as a weight-loss strategy. The relationship between social pressure for female slenderness, dieting, and eating disorders are discussed.

Adolescent↗
PubMed1991

Self-reported eating disorders of black, low-income adolescents: behavior, body weight perceptions, and methods of dieting.

This study identified black, low-income adolescents who thought they had anorexia nervosa or bulimia nervosa, identified behaviors common to those who thought they had the disorders, and compared their actual and perceived body weight as well as methods of dieting. Of the 1,930 students in grades 7-12 who participated, about 12% thought they might have an eating disorder. These students also reported having food-related behaviors similar to individuals with eating disorders and which differed significantly from those reported by their peers. Gender was more likely to affect food behavior than age. Though most students were within their expected weight range, those with self-reported eating disorders perceived themselves to be heavier more often than their peers and when their actual weights were compared, they were more likely to weigh more. Of those who had dieted to lose weight, fasting was the most frequently reported restrictive method used.

Adolescent↗
PubMed1989

The relationship of body image perception and weight status to recent change in weight status of the adolescent female.

This descriptive correlational study investigated the relationship of body image perception and weight status to recent change in weight status of the adolescent female. Based on earlier research findings supporting the position that obese adolescent females demonstrate a negative body image perception as compared to the nonobese, this investigation identified the need to study body image perception as it applies to all adolescent females and to include a recent change in weight status as it may affect that perception. A convenience sample of 90 adolescent females between the ages of 13 and 17 years was selected from health and gym classes at a large midwestern metropolitan high school. Subjects were grouped into three categories: nonobese, overweight, and obese based on height, weight, and skinfold measurement. They were administered two questionnaires: the Body-Cathexis Scale and a self-report recent change in weight status and demographic questionnaire. Results indicated a significant positive correlation for the overall association of body image perception and weight status. When the analysis was partialled according to defined weight groups, the relationship held only for the overweight group. Differences in body image scores were obtained in association with each of the recent change-in-weight-status questions. Findings confirmed the need to study the association between body image perception and weight status to recent change in weight status with a more heterogeneous group of adolescent females.

Adolescent↗
PubMed1989

Black and white adolescents' perceptions of their weight.

Black and white adolescents' perceptions of their weight were examined in this study. A 22-item questionnaire on weight perceptions and weight control was administered to 341 adolescents from two inner city schools in the midwest (138 black and 193 white students). Students were classified as thin, normal, or heavy based on National Health Survey data on height and weight measurements for youth ages 12-17. Significant differences (p less than .05) occurred in how the heavy black and white males and females perceived their weight in comparison to actual weight. All heavy white females perceived they were heavy, in comparison to only 40% of heavy black females; 78% of heavy white males labeled themselves heavy vs. 36% of heavy black males. Thin black and white females were dieting and exercising to lose weight and thin white males were exercising to lose weight. Black males were significantly more likely to believe emotions did not affect their weight when compared to white males. Black females believed exercise levels accounted for their weight, while white females attributed their weight to eating habits. Beliefs about exercise and eating contributed 23% to the variance found in perceived weight status of black males. White males believed access to food and their emotions accounted for their perceived weight. Leading sources of weight control information regardless of ethnicity were television, family members, friends and magazines for females; males used TV, family members, and athletic coaches.

Adolescent↗
PubMed1990

Weight and perceptions of body image in women and men in a Sydney sample.

Using a modification of the distorting camera technique, 50 obese women (body mass index (BMI; kg/m2 35.1 +/- 1.1), 40 obese men (BMI 38.2 +/- 1.5) and their respective normal weight controls estimated their body size. The obese women, control women and obese men overestimated their body size, whilst control weight men were accurate. The control men were satisfied with their body size, control women less so and the obese were unsatisfied. Whilst the control women considered themselves overweight (BMI 26.7 +/- 0.8 compared to actual BMI 23.1 +/- 0.5, P less than 0.001) their preferred and actual body sizes were identical. There were no differences between obese subjects and controls in the sizes they considered healthy and attractive. The accepted normal size range for a woman was lower than that accepted for men. Older men (both obese and normal weight) accepted larger sizes for women than younger men. These results show that the obese overestimated their body size and supports the notion that there is social pressure on women to strive towards a slimmer ideal, whilst overweight men are more accepted.

Adult↗
PubMed1991

Perceptions of weight and attitudes toward eating in early adolescent girls.

Sixth grade girls (n = 206) responded to questions about their weight, body image, dieting practices, and attitudes toward weight and eating. Results suggested that feeling too fat and wishing to lose weight were becoming normative for young adolescent girls in that the majority of girls wished to weigh less and said that they dieted at least occasionally. For most girls, weight concerns had emerged between the ages of 9 to 11. A sizeable proportion of girls seemed to have adopted a "dieting mentality," claiming to be avoiding fat, counting calories, thinking excessively about food, feeling guilty after eating and overeating, and exercising to lose weight. Such practices were common even among girls who did not describe themselves as overweight or who were satisfied with their appearance. The emergence of these attitudes and behaviors at increasingly younger ages is of grave concern, as several of them are risk factors for the development of serious eating disorders.

Attitude to Health↗
PubMed1988

Patient perceptions and weight loss of obese adults.

Little is known about the relative importance of self-image, physician attention to obesity, weight-loss program participation, exercise, self-motivation, and nutrition knowledge in the process of weight loss. Fifty-six obese adults who had been patients in a university family practice setting for at least five years between 1980 and 1986 were surveyed by telephone. Questions were designed to determine factors considered important to obese individuals in their weight-loss efforts and to determine factors related to weight loss among obese individuals. Nearly all of the survey participants felt that they had a good knowledge of nutrition and that they applied their knowledge of nutrition to their daily eating. They did not feel that additional knowledge of nutrition would help them control their obesity. Participants reporting physician attention to their obesity and recent weight-loss program experience were more likely to be categorized as weight losers over the five-year interval. Factors felt to be important in their weight loss by most patients who lost weight at some time were exercise and self-motivation.

Body Weight↗
PubMed1987

Kinematic form and scaling: further investigations on the visual perception of lifted weight.

Observers are able to judge accurately the weight lifted by another person when only the motions of reflective patches attached to the lifter's major limb joints and head can be seen (Runeson & Frykholm, 1981). What properties of these complex kinematic patterns allow judgments of weight to be made? The pattern of variation in velocity of the lifted object over position is explored as a source of information for weight: It is found to provide limited information. How are variations in kinematic patterns scaled to allow judgments of weight, a kinetic quantity? The possibility of a source of information for scaling in the kinematics is investigated. Judgments based only on patch-light displays are accurate to a degree that is improved by an extrinsic scaling basis. Finally, the sensitivity to scaling of alternative metrics used in judging is explored. Intrinsic metrics are discovered to be less sensitive to the absence of an extrinsic basis for scaling.

Concept Formation↗
PubMed1992

Adolescents' perceptions of relative weight and self-reported weight loss activities.

Data from the 1990 North Carolina Youth Risk Behavior Survey (YRBS) were used to examine adolescents' perceptions of relative weight and the relationship of these perceptions to physical activity levels, efforts to lose weight, and time spent viewing television. A total of 3,437 ninth and 12th grade respondents to the May 1990 survey were included in the analysis. Of this sample, 25% perceived themselves as "too fat." Of that group, 68% were trying to lose weight. Females made up 75% of those reporting they were "too fat" and were trying to lose weight. White females were more likely to think of themselves as overweight and were more likely to be trying to lose weight than black females. Adolescents who perceived themselves as "too fat" reported fewer days of strenuous activity, fewer hours of strenuous exercise in physical education classes, and more hours spent viewing television on school days.

Adolescent↗
PubMed1979

Quantitative protein changes in the hypothalamic neurons of pubertal male rats, castrated neonatally.

The effect of neonatal castration of male rats on the sexual differentiation of the hypothalamus at puberty was studied. Male rats were castrated on days 1, 5 and 7 after birth. Their brains were processed for study on days 83-85. The neurons and cell nuclei of the preoptic area, mediobasal and ventromedial nuclei were assessed for changes in cell and nuclear sizes and dry weight (calculated using interferometric methods). Neonatal castration resulted in size as well as dry weight increase in the neurons of the anterior and mediobasal hypothalamus. The dry weight increased by 34% (P less than 0.001) in the medial preoptic area, by 25% (P less than 0.001) in the arcuate neurons and by 22% (P less than 0.001) in the ventromedial nucleus. The cell nuclei exhibited perceptible weight increase too--in the medial preoptic area 68% (P less than 0.001); 55% in the arcuate neurons (P less than 0.001), and 39% in the ventromedial region. The weight and size increases in neonatally castrated males were equal to those of females of the same age. In rats castrated on day 7, the cell sizes and dry weights of the ventromedial nucleus increased but the cell nuclei exhibited only little change. It is assumed that the changes in the dry weight may be the result of increased synthetic processes in these groups of neurons which are connected with the tonic and cyclic release of gonadotropins. These changes also point to the hypothalamic differentiation shifting to the female type in the absence of the inducing effect of androgens.

Animals↗
PubMed2025

Differential gene expression study in whole blood identifies candidate genes for psychosis in African American individuals.

Genome-wide association has identified regions of the genome that mediate risk for psychosis. It is possible that variants in these regions confer risk by altering gene expression. This work has predominantly been conducted in individuals of European descent and has focused narrowly on schizophrenia rather than psychosis as a syndrome. In the present study we investigated alterations in gene expression in African American individuals with a range of psychotic diagnoses to increase understanding of the etiology in an underserved population. We performed RNA-seq in whole bloody to survey the transcriptome in 126 patients with a psychosis-spectrum disorder and 217 healthy controls and applied differential gene expression analyses across the genome while controlling for age, sex, population stratification and batch. We found 18 differentially expressed genes (DEGs), some of the locations of the corresponding genes overlap with previously implicated regions for psychosis, but many of which were novel associations. Enrichment analysis of nominally significant genes (p&#xa0;<&#xa0;0.05) revealed overrepresentation of biological processes relating to platelet, immune and cellular function, and sensory perception. Weighted gene co-expression network analysis, applied to identify modules of co-expressed genes associated with psychosis, revealed 10 modules, one of which was significantly associated with psychosis. This module was significantly enriched for DEGs, and for platelet function. These results support the potential role of immune function in the etiology of psychosis, identify novel candidate gene expression phenotypes that correspond to both established and new genomic regions, in individuals of African American ancestry.

Humans↗
PubMed1992

Temporal patterning in cascade juggling.

A key variable in cascade juggling is the proportion of time that a juggler holds onto a juggled object during a hand cycle, that is, the time from catch to throw in relation to the time from catch to catch. Space-time constraints and principles of frequency locking suggest 3/4 as the primary ratio and 2/3 and 5/8 as the most accessible options. In 5 experiments, object number, mass, and type (ball or scarf) were manipulated together with the frequency at which the objects were juggled. With 5 or 7 balls, the ratio was 3/4, independent of frequency. With 3 balls, the ratio decreased with frequency, with 3/4, 2/3, and 5/8 tending to predominate independently of the force variations induced by variation in object mass. With 3 scarves, ratios varied inversely with frequency and often exceeded 3/4. Implications for a dynamical theory of juggling were discussed with the issue of relative timing in coordination and the manipulation of task constraints as an experimental strategy.

Attention↗
PubMed1975

On the psychophysical law: an information theory interpretation.

For more than a century Fechner's psychophysical law has been the subject of dispute and debate. Fechner based his law on Weber's indisputable observations and measurements. Yet, using these observations as a starting point, but measuring information instead of sensation, one may arrive at numerical laws quite different from Fechner's psychophysical law.

Differential Threshold↗