Weight bias and weight loss treatment outcomes in treatment-seeking adults.

BACKGROUND: Few studies have explored the relationship between weight bias and weight loss treatment outcomes. PURPOSE: This investigation examined the relationship between implicit and explicit weight bias and (a) program attrition, (b) weight loss, (c) self-monitoring adherence, (d) daily exercise levels and overall caloric expenditure, (e) daily caloric intake, and (f) daily caloric deficit among overweight/obese treatment-seeking adults. METHODS: Forty-six overweight/obese adults (body mass index > or = 27 kg/m(2)) participating in an 18-week, stepped-care, behavioral weight loss program completed implicit and explicit measures of weight bias. Participants were instructed to self-monitor and electronically report daily energy intake, exercise, and energy expenditure. RESULTS: Greater weight bias was associated with inconsistent self-monitoring, greater caloric intake, lower energy expenditure and exercise, creation of a smaller caloric deficit, higher program attrition, as well as less weight loss during the self-help phase of the stepped-care treatment. CONCLUSIONS: Weight bias may interfere with overweight/obese treatment-seeking adults' ability to achieve optimal health.

Can following the caloric restriction recommendations from the Dietary Guidelines for Americans help individuals lose weight?

BACKGROUND: The Dietary Guidelines for Americans recommend creating an energy deficit of at least 500 kcal a day to facilitate weight loss. This investigation examined the relationship between creating a consistent, self-reported energy deficit of at least 500 kcal a day and weight loss. The relationship between self-monitoring adherence and daily energy intake and expenditure and weight loss was also examined. METHODS: Fifty-four overweight or obese adults (BMI>or=27 kg/m(2)) participating in a 14-week weight loss program were given a 5% total body weight loss goal and instructed to create an energy deficit of at least 500 kcal a day to facilitate weight loss. Participants provided daily records of total energy intake and expenditure, physical activity, and weekly and overall weight loss during treatment. RESULTS: Individuals who averaged an energy deficit in excess of 500 kcal per day lost nearly four times the weight as individuals whose average energy deficit was below 500 kcal per day (p<.01). Individuals who lost 5% of their body weight during the intervention self-monitored more than twice as many days than individuals who failed to lose 5% of their body weight (p<.01). CONCLUSION: Individuals interested in losing weight should continue to be advised to regularly self-monitor energy intake and expenditure as well as to create a consistent daily energy deficit (e.g., 500 kcal day).

Skipping meals and alcohol consumption. The regulation of energy intake and expenditure among weight loss participants.

Research suggests that specific eating patterns (e.g., eating breakfast) may be related to favorable weight status. This investigation examined the relationship between eating patterns (i.e., skipping meals; consuming alcohol) and weight loss treatment outcomes (weight loss, energy intake, energy expenditure, and duration of exercise). Fifty-four overweight or obese adults (BMI> or =27 kg/m(2)) participated in a self-help or therapist-assisted weight loss program. Daily energy intake from breakfast, lunch, dinner, and alcoholic beverages, total daily energy intake, total daily energy expenditure, physical activity, and weekly weight loss were assessed. On days that breakfast or dinner was skipped, or alcoholic beverages were not consumed, less total daily energy was consumed compared to days that breakfast, dinner, or alcoholic beverages were consumed. On days that breakfast or alcohol was consumed, daily energy expenditure (breakfast only) and duration of exercise were higher compared to days that breakfast or alcohol was not consumed. Individuals who skipped dinner or lunch more often had lower energy expenditure and exercise duration than individuals who skipped dinner or lunch less often. Individuals who consumed alcohol more often had high daily energy expenditure than individuals who consumed alcohol less often. Skipping meals or consuming alcoholic beverages was not associated with weekly weight loss. In this investigation, weight loss program participants may have compensated for excess energy intake from alcoholic beverages and meals with greater daily energy expenditure and longer exercise duration.

Learning to perceive differences in solid shape through vision and touch.

A single experiment was designed to investigate perceptual learning and the discrimination of 3-D object shape. Ninety-six observers were presented with naturally shaped solid objects either visually, haptically, or across the modalities of vision and touch. The observers' task was to judge whether the two sequentially presented objects on any given trial possessed the same or different 3-D shapes. The results of the experiment revealed that significant perceptual learning occurred in all modality conditions, both unimodal and cross-modal. The amount of the observers' perceptual learning, as indexed by increases in hit rate and d', was similar for all of the modality conditions. The observers' hit rates were highest for the unimodal conditions and lowest in the cross-modal conditions. Lengthening the inter-stimulus interval from 3 to 15 s led to increases in hit rates and decreases in response bias. The results also revealed the existence of an asymmetry between two otherwise equivalent cross-modal conditions: in particular, the observers' perceptual sensitivity was higher for the vision-haptic condition and lower for the haptic-vision condition. In general, the results indicate that effective cross-modal shape comparisons can be made between the modalities of vision and active touch, but that complete information transfer does not occur.

Taking control of your personal eating and exercise environment: a weight maintenance program.

The current investigation examined the impact of a weight maintenance intervention (MI) designed to empower people to create a personal healthy food and physical activity environment on weight loss treatment outcomes. It was hypothesized that behavioral weight loss program (BWLP) participants who received an additional MI would evidence superior weight loss maintenance compared to participants who received a BWLP alone (no contact [NC]). Fifty-one obese adults were randomly assigned to participate in a 16-week weight loss intervention followed by NC or a 6-week MI. Thirty-eight participants completed the six-month follow-up. Body weight, percent body fat, cardiorespiratory fitness, self-reported physical activity, and self-reported diet (i.e., calories, percent daily intake of fat, protein, and carbohydrates) were assessed. Participants significantly decreased their weight, increased physical activity/fitness, and improved dietary intake (ps<.05). MI participants had significantly greater weight loss maintenance than NC participants (ps<.05). Helping obese individuals to modify their personal eating and physical activity environment in order to reduce exposure to "obesogenic" cues may contribute to long-term weight loss maintenance.

Aging and the perception of 3-D shape from dynamic patterns of binocular disparity.

In two experiments, we investigated the ability of younger and older observers to perceive and discriminate 3-D shape from static and dynamic patterns of binocular disparity. In both experiments, the younger observers' discrimination accuracies were 20% higher than those of the older observers. Despite this quantitative difference, in all other respects the older observers performed similarly to the younger observers. Both age groups were similarly affected by changes in the magnitude of binocular disparity, by reductions in binocular correspondence, and by increases in the speed of stereoscopic motion. In addition, observers in both age groups exhibited an advantage in performance for dynamic stereograms when the patterns of binocular disparity contained significant amounts of correspondence "noise." The process of aging does affect stereopsis, but the effects are quantitative rather than qualitative.

Visual discrimination of local surface structure: slant, tilt, and curvedness.

In four experiments, observers were required to discriminate interval or ordinal differences in slant, tilt, or curvedness between designated probe points on randomly shaped curved surfaces defined by shading, texture, and binocular disparity. The results reveal that discrimination thresholds for judgments of slant or tilt typically range between 4 degrees and 10 degrees; that judgments of one component are unaffected by simultaneous variations in the other; and that the individual thresholds for either the slant or tilt components of orientation are approximately equal to those obtained for judgments of the total orientation difference between two probed regions. Performance was much worse, however, for judgments of curvedness, and these judgments were significantly impaired when there were simultaneous variations in the shape index parameter of curvature.

The perception of distances and spatial relationships in natural outdoor environments.

The ability of observers to perceive distances and spatial relationships in outdoor environments was investigated in two experiments. In experiment 1, the observers adjusted triangular configurations to appear equilateral, while in experiment 2, they adjusted the depth of triangles to match their base width. The results of both experiments revealed that there are large individual differences in how observers perceive distances in outdoor settings. The observers' judgments were greatly affected by the particular task they were asked to perform. The observers who had shown no evidence of perceptual distortions in experiment 1 (with binocular vision) demonstrated large perceptual distortions in experiment 2 when the task was changed to match distances in depth to frontal distances perpendicular to the observers' line of sight. Considered as a whole, the results indicate that there is no single relationship between physical and perceived space that is consistent with observers' judgments of distances in ordinary outdoor contexts.

Aging and the perception of depth and 3-D shape from motion parallax.

The ability of younger and older observers to perceive 3-D shape and depth from motion parallax was investigated. In Experiment 1, the observers discriminated among differently curved 3-dimensional (3-D) surfaces in the presence of noise. In Experiment 2, the surfaces' shape was held constant and the amount of front-to-back depth was varied; the observers estimated the amount of depth they perceived. The effects of age were strongly task dependent. The younger observers' performance in Experiment 1 was almost 60% higher than that of the older observers. In contrast, no age effect was obtained in Experiment 2. Older observers can effectively perceive variations in depth from patterns of motion parallax, but their ability to discriminate 3-D shape is significantly compromised.

The visual and haptic perception of natural object shape.

In this study, we evaluated observers' ability to compare naturally shaped three-dimensional (3-D) objects, using their senses of vision and touch. In one experiment, the observers haptically manipulated 1 object and then indicated which of 12 visible objects possessed the same shape. In the second experiment, pairs of objects were presented, and the observers indicated whether their 3-D shape was the same or different. The 2 objects were presented either unimodally (vision-vision or haptic-haptic) or cross-modally (vision-haptic or haptic-vision). In both experiments, the observers were able to compare 3-D shape across modalities with reasonably high levels of accuracy. In Experiment 1, for example, the observers' matching performance rose to 72% correct (chance performance was 8.3%) after five experimental sessions. In Experiment 2, small (but significant) differences in performance were obtained between the unimodal vision-vision condition and the two cross-modal conditions. Taken together, the results suggest that vision and touch have functionally overlapping, but not necessarily equivalent, representations of 3-D shape.