Can adults accurately judge child weight status?

Background/objectives: This study addresses two questions: what body sizes/shapes do participants believe correspond to the boundaries of the National Child Measurement Programme (NCMP) weight categories for children aged 4–5 and 10–11 years old, and are these judgements altered by using terminology encouraging positive action by parents? Methods: The study used photorealistic computer-generated stimuli based on 388 3D scans of children in a method of adjustment task. We first asked participants to estimate the boundaries between weight status categories as described by the NCMP. To test validity, we asked a second set of participants to estimate the body that represented exemplars of each weight category (the exemplars should fall between the boundary estimates). We then recruited a third set of participants to determine whether substituting positive action terminology for the weight status definitions altered the boundary positions. Results: First, validity was confirmed. Second, we found a compressed response range (lower weights overestimated and higher weights underestimated) for the positioning of both categorical boundaries and exemplars. Finally, the use of alternative weight status terminology resulted in an upward shift in the position of all boundaries in the BMI spectrum but failed to remove the compressive stimulus response effect. Discussion: There is a disconnect between the child size that people perceive to correspond to the different weight categories and the size criteria used by health professionals, and it is likely that this gap can only be bridged by training to recognise the medically based categories.</p

The MapMe Body Scales: Validity and reliability of a biometrically accurate, photorealistic set of child body size scales

Background/Objectives: It is vital to identify children whose weight status means that they may benefit from medical or behavioural support, but adult visual judgements of child weight status are inaccurate, and children are seldom routinely weighed and measured. Consequently, there is a need for validated visual tools for use in training, communication, and interventions relating to child weight. Methods: This paper presents validation data for a set of innovative photo-realistic colour body size scales depicting boys and girls aged 4–5 and 10–11. Each age- and gender-specific scale consists of 7 figures based on three-dimensional (3D) scans of 388 children to accurately represent the change in body size caused by changing adiposity. To assess scale validity, 238 adult participants (105 men, 132 women, 1 non-binary individual) undertook two tasks: rating figure adiposity using a visual analogue scale and ranking figures in ascending order of adiposity (OSF Reference: gdp9j). Results: Participants accurately estimated the relative adiposity of each figure, i.e., they were able to tell the difference between figures and correctly rank them by size. This demonstrates scale validity for use in body size tasks. One hundred and fifty-one participants also provided 3-day test–retest data, which demonstrates excellent short-term reliability. Conclusions: Overall, the MapMe child body size scales provide an anthropometrically accurate, valid, reliable, and usable tool for size-related tasks and communication with adults regarding child weight.</p

Perceptual body image tasks require ethnically appropriate stimuli

Current body ideals and perceived weight status are often assessed with tests that include images which depict BMI dependent morphological changes in body shape. These images are almost exclusively based on White European (WE) bodies. However, East Asian (EA) and South Asian (SA) people have a different body composition and pattern of adipose deposition for a given BMI. As such, matching someone’s body from an EA or SA background to a WE body may lead to errors in estimation, as there are no equivalent bodies to match against. Therefore, we 3D scanned EA, SA and WE female volunteers and constructed computer-generated imagery (CGI) bodies based on a statistical analysis of the size and shape variation specific to each ethnic identity. We then asked participants to make judgements between pairs of bodies of the same or different ethnic identity as themselves. When presented with ethnically different stimuli, EA and SA participants significantly over-estimate body size and WE participants significantly under-estimate. Additionally, ethnically mismatched stimuli lead to significantly greater uncertainty about body size judgements. For the first time, we show that ethnically appropriate stimuli need to be used to assess body judgements and should be developed as a matter of urgency.</p

The effect of own body concerns on judgments of other womens body size

 We investigated the relationships between healthy women’s estimates of their own body size, their body dissatisfaction, and how they subjectively judge the transition from normal to overweight in other women’s bodies (the “normal/overweight” boundary). We propose two complementary hypotheses. In the first, participants compare other women to an internalized Western “thin ideal,” whose size reflects the observer’s own body dissatisfaction. As dissatisfaction increases, so the size of their “thin ideal” reduces, predicting an inverse relationship between the “normal/overweight” boundary and participants’ body dissatisfaction. Alternatively, participants judge the size of other women relative to the body size they believe they have. For this implicit or explicit social comparison, the participant selects a “normal/overweight” boundary that minimizes the chance of her making an upward social comparison. So, the “normal/overweight” boundary matches or is larger than her own body size. In an online study of 129 healthy women, we found that both opposing factors explain where women place the “normal/overweight” boundary. Increasing body dissatisfaction leads to slimmer judgments for the position of the “normal/overweight” boundary in the body mass index (BMI) spectrum. Whereas, increasing overestimation by the observer of their own body size shifts the “normal/overweight” boundary toward higher BMIs. </p

Personal ideal, cultural ideal and optimal attractiveness: Are these constructs for body size and shape the same or different?

There has been an assumption in the literature that the three concepts of ideal body shape (personal ideal, cultural ideal, and the most attractive body shape) are effectively the same percept. To test this presumption, 554 participants completed either a between- or within-subjects condition using a matrix of 32 bodies varying in two dimensions: muscle and adiposity. Three separate groups of participants were recruited to the between-subjects design and made only one of these judgements, whilst participants in the within-subjects version completed all three of these judgments. These bodies are based on 3D scans of 221 women’s bodies and so accurately represent the change in size and shape caused by changing body composition. The participants also completed a set of psychometric questionnaires to index the degree to which external concepts of body image have been internalised. The results show that in both conditions, all three judgements collapse onto the same average preferred body shape, with low adiposity and relatively high muscularity. However, this masked systematic differences in responses between personal ideals and the other body judgements, which may be explained by a difference in how information directly related to oneself is processed relative to more abstract third person judgements.</p