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Biomedical subjects

S A Stoner

Publications and source records attributed to S A Stoner.

10 recordsLinked to original sources
PubMed2000

Effects of acute food deprivation on eating behavior in eating disorders.

OBJECTIVE: Effects of acute food deprivation on eating behavior in bulimic patients and controls were investigated. It was predicted that food deprivation would increase overall food intake and result in overeating in bulimics. METHOD: Following 19 hr of food deprivation (in which breakfast and lunch were skipped), or no deprivation, food intake was measured in 9 inpatients with anorexia nervosa (binge eating/purging subtype, ANB), 10 inpatient (BN/in) and 9 outpatient (BN/out) normal-weight bulimics, and 11 unrestrained and 10 restrained controls. RESULTS: A general trend for increased food intake following deprivation was found. However, only BN/in patients consumed significantly more and selected higher energy foods following deprivation. ANB patients demonstrated the greatest degree of variability in intake and the least magnitude of change in ratings as a function of eating. DISCUSSION: A period of acute food deprivation did not trigger marked eating pathology as evidenced by overconsumption. Chronic dietary restraint may be a more potent precipitating factor in overeating than absolute number of hours of food restriction.

Adult↗
PubMed2000

Alcohol expectancies and sexuality: a self-fulfilling prophecy analysis of dyadic perceptions and behavior.

OBJECTIVE: We evaluated the self-fulfilling prophecy hypothesis that belief in an "alcohol enhances/stimulates sex" expectancy fosters heightened sexual behavior-via effects on intermediate sexual perceptions. To test this notion, we investigated the effects of self-reported alcohol expectancies, alcohol expectancy set and a co-participant's gender and apparent drinking status on dyadic viewing of erotica. METHOD: Sex-related alcohol expectancies were assessed in 100 male moderate social drinkers. In a subsequent session, participants were led to believe they were consuming either alcoholic or nonalcoholic drinks. No alcohol was actually administered. Each participant rated his sexual arousal, rated an alcohol-drinking or nondrinking co-participant on sexual disinhibition and then viewed erotic slides with the co-participant. Slide viewing times were assessed unobtrusively. RESULTS: Path analysis revealed support for the self-fulfilling prophecy hypothesis: Expectancy score (moderated by alcohol expectancy set) heightened viewing indirectly via effects on sexual arousal (beta = .26) and perceived disinhibition (beta = .25). Sexual arousal in turn predicted perceived disinhibition (beta = .37), which in turn predicted viewing (beta = .23). Co-participant drinking had direct (beta = .21) and indirect (beta = .40 via perceived disinhibition) effects on viewing. CONCLUSIONS: Alcohol expectancy variables-apart from alcohol-interactively determined men's responding in a dyadic sexual situation. Consistent with psychosocial formulations, predrinking expectancy steered postdrinking perceptions along an expectancy-congruent course to shape subsequent behavior. Thus, alcohol's role in stimulating men's sexual responding cannot be construed as occurring through a strictly pharmacological mechanism. Speculations about the comparative domains of expectancy versus alcohol explanations are discussed.

Adult↗
PubMed2000

Understanding acute alcohol effects on sexual behavior.

Alcohol has been implicated as having a causal role in a variety of sexual processes and outcomes. We review nonexperimental research illustrating the nature of alcohol's association with sexuality. Methodological considerations limiting causal assertions permissible with nonexperimental data are discussed. We also review findings from experiments, mostly analogue paradigms, examining the effects of alcohol on genital arousal, sexual risk taking, and sexual assault. In each case, it is observed that alcohol can exert a causal effect on one or more of the constituent responses undergirding these phenomena. We conclude that alcohol does appear to have a causal impact on many sexuality indices studied in laboratory conditions. Both alcohol expectancy and alcohol myopia models have been applied to explain these causal linkages. Expectancy models seem to account well for postdrinking sexual reactions and perceptions. Overall, myopia analyses seem to offer the most persuasive explanations of postdrinking expressions of sexual risk taking and sexual assault.

Acute Disease↗
PubMed1997

Effects of preloads of differing energy and macronutrient content on eating behavior in bulimia nervosa.

Evidence suggests that bulimics demonstrate blunted satiety possibly due to repeated episodes of overeating. This suggestion was tested further by comparing responses to yogurt preloads differing in carbohydrate and fat relative to a lower energy control yogurt in 12 bulimics and 12 age- and weight-matched controls. Participants were tested on three occasions at lunchtime. On each occasion, appetite and mood were rated before and after receiving a lunch of raspberry yogurt (350 g). Covert manipulation of energy and nutrient content was achieved by matching the yogurts on sensory properties and formulating a control yogurt (161 kcal), a high-fat version (357 kcal: 65% calories from fat), and a high-carbohydrate version (357 kcal: 81% calories from carbohydrate). Although there were no differential effects of the preloads on intake of an ad libitum test meal given 5 hr later in either the control or bulimic groups, there were significant differences in test meal energy intake between groups. On average and with all conditions combined, bulimics ate significantly fewer calories (775 +/- 167 kcal) than controls (1182 +/- 94 kcal) and consumed a greater percentage of calories from carbohydrate than controls. Bulimics restricted their intake relative to controls, and chose foods low in fat. This study provides further evidence of restricted eating in bulimia nervosa when the opportunity to purge is not available. Furthermore, the present study suggests that intake by bulimics is not influenced by nutrient content per se but by consideration of the caloric value of foods and the consequences of eating certain foods for weight control.

Adult↗
PubMed1996

Food preferences and desire to eat in anorexia and bulimia nervosa.

OBJECTIVE: To determine whether eating disordered patients and controls differ in visual analog scale (VAS) ratings of liking and desire to eat various foods and whether ratings differ according to caloric or macronutrient content of the foods. METHOD: Fifty-five female inpatients with eating disorders and 15 controls rated their liking of and desire to eat 50 common foods at admission and discharge using 100-mm VAS. RESULTS: All patient groups rated their desire to eat high-calorie foods significantly lower than their desire to eat low-calorie foods whereas controls rated their desire to eat high- and low-calorie foods equally. Patients also differed from controls more in ratings of desire to eat than in liking when foods were classified according to macronutrient content. In restricting anorexics (N = 25), ratings of liking and desire to eat for high-fat/low-carbohydrate (CHO) and high-fat/high-CHO foods were not significantly correlated at admission. Disparity in correlations between restrictors, bulimics (N = 18), and controls was attenuated with treatment while anorexics with bulimic features (N = 12) became less like controls from admission to discharge. DISCUSSION: Differences in the way patients and controls perceive foods should be borne in mind during the treatment process. Furthermore, since patients had not completely normalized by discharge, treatment strategies should emphasize acceptance of foods varying in macronutrient and caloric content, as intake of a varied diet is of key importance in regaining and maintaining good health.

Adult↗
PubMed1996

Improved eating behavior in eating-disordered inpatients after treatment: documentation in a naturalistic setting.

OBJECTIVE: Abnormalities of eating behavior are definitional components of eating disorders (ED), but are seldom observed directly. This study assessed abnormalities of eating behavior in ED patients before treatment and documented changes after multidisciplinary treatment. METHOD: Thirty-three ED patients (13 ANR, 10 ANB, 10 BN) and 10 controls selected a lunch meal in a cafeteria before and after treatment with energy intake (kilocalories) and macronutrients covertly observed. Visual analog scales (VAS) measured hunger and satiety. RESULTS: Before treatment, all ED patient groups experienced low hunger and high fullness, compared to controls. After treatment, hunger increased and satiety decreased. ANR patients, after treatment, increased energy intake from 366 to 916.5 kcal (p < .001), while BN patients increased from 409.9 to 663 kcal (p = .03). ANB nonsignificantly increased. ANR chose significantly more fats (22.7% to 36.2%, p = .05). DISCUSSION: Treatment partially normalizes pre-meal hunger and satiety in ED patients and significantly improves eating behavior (total energy intake and fat content) in ANR and BN patients. Reasons for nonsignificant changes in ANB are not obvious. We recommend documentation of eating behavior by simple, inexpensive, observational methods in a naturalistic setting before and after treatment of ED patients.

Adolescent↗
PubMed1995

Olfactory dysfunction in anorexia and bulimia nervosa.

Fifty-five eating-disordered women and 16 normal controls participated in this study to determine whether olfactory function is altered in patients with food-restricting anorexia, anorexia with bulimic features, and bulimia nervosa. Olfactory function was assessed using the University of Pennsylvania Smell Identification Test and by determining phenyl ethyl alcohol odor detection thresholds. Only the very low-weight anorexics showed impairments in their identification and detection of odors. This group's olfactory function did not improve from admission to discharge despite significant weight gain. Although, overall, smoking had only a minor influence on olfactory function, the very low-weight anorexic smokers had the lowest scores of all subjects. Since higher-weight anorexics did not show such impairments, the results suggest that the severe and prolonged starvation experienced by the very low-weight anorexics caused or contributed to intractable deficits in the olfactory system and that these deficits are compounded by smoking.

Adolescent↗
PubMed1994

Satiety after preloads with different amounts of fat and carbohydrate: implications for obesity.

High intake of dietary fat may be key in both the etiology and maintenance of obesity. Because a reduction in the proportion of energy derived from fat will be accompanied by an increase in the proportion of energy derived from carbohydrate, this study compared the effects of these macronutrients on eating behavior in obese and lean individuals. The effects of different amounts of fat and carbohydrate, covertly incorporated into yogurt preloads, on subsequent food intake, hunger, and satiety were assessed. A group of 12 normal-weight men, unconcerned about eating and body weight (unrestrained), accurately compensated for the energy in the preloads regardless of the nutrient composition. Other groups (n = 12 per group), including normal-weight restrained men and normal-weight and obese restrained and unrestrained females, did not show such orderly energy compensation; joule-for-joule, the high-fat preloads suppressed intake at lunch less than did high-carbohydrate preloads. These results suggest that a relative insensitivity to the satiating effect of fat could be involved in the development and maintenance of obesity.

Adult↗
PubMed1990

Hemodynamic effects of Gd-DTPA administered via rapid bolus or slow infusion: a study in dogs.

The hemodynamic effects of rapid (10 sec) versus slow (1 min) IV injection of Gd-DTPA were compared in normal, pentobarbital-anesthetized mongrel dogs. Hypertonic mannitol and isotonic saline were used as equiosmotic and equivolumetric controls. Two dose levels of Gd-DTPA were administered: 0.1 mmol/kg and 0.5 mmol/kg, corresponding to dose volumes of 0.2 and 1.0 ml/kg, respectively. The rapid injection of a high dose (0.5 mmol/kg) produced a transient decrease in arterial blood pressure (21 mm Hg, p less than .001), which returned to control values within 1 min after the injection. Slow IV infusion at this high dose had no statistically significant hemodynamic effects. There were no statistically significant effects of the lower dose (0.1 mmol/kg) administered as a bolus or by infusion, nor of the saline or osmotic control solutions. These results suggest that acute hemodynamic effects of Gd-DTPA are not observed at clinically relevant doses and the vasodilation observed at a higher dose may result from a direct action of the contrast agent.

Analysis of Variance↗