Easton Jonathan F, Stephens Christopher R, Román Sicilia Heriberto
C3-Centro de Ciencias de la Complejidad, Universidad Nacional Autónoma de México, Circuito Centro Cultural s/n, Ciudad Universitaria, Col. Universidad Nacional Autónoma de México, Del. Coyoacán, C.P. 04510 Ciudad de México, Mexico.
Instituto de Ciencias Nucleares, Universidad Nacional Autónoma de México, Circuito Exterior s/n, Ciudad Universitaria, Col. Universidad Nacional Autónoma de México, Del. Coyoacán, A. P. 70-543, C.P. 04510 Ciudad de México, Mexico.
BMC Obes. 2017 May 3;4:16. doi: 10.1186/s40608-017-0152-6. eCollection 2017.
This study analysed the relationship between perceived and actual Body Mass Index (BMI) and the effect of a prior identification of obesity by a medical professional for adults using difference in response for two distinct BMI self-perception questions. Typically, self-perception studies only investigate the relation with current weight, whereas here the focus is on the self-perception of weight differences.
A statistical approach was used to assess responses to the Mexican ENSANUT 2006 survey. Adults in the range of BMI from 13 to 60 were tested on responses to a categorical question and a figure rating scale self-perception question. Differences in response by gender and identification of obesity by a medical professional were analysed using linear regression.
Results indicated that regardless of current BMI and gender, a verbal intervention by a medical professional will increase perceived BMI independently of actual BMI but does not necessarily make the identified obese more accurate in their BMI estimates. A shift in the average self-perception was seen with a higher response for the identified obese. A linear increase in perceived BMI as a function of actual BMI was observed in the range BMI < 35 but with a rate of increase much less than expected if weight differences were perceived accurately.
Obese and overweight Mexican adults not only underestimated their weight, but also, could not accurately judge changes in weight. For example, an increase of 5 kg is imagined, in terms of self-image, to be considerably less. It was seen that an identification of obesity by a health care professional did not improve ability to judge weight but, rather, served as a new anchor from which the identified obese judge their weight, suggesting that even those identified obese who have lost weight, perceive their weight to be greater than it actually is. We believe that these results can be explained in terms of two cognitive biases; the self-serving bias and the anchoring bias.
本研究通过对两个不同的体重指数（BMI）自我认知问题的回答差异，分析了成年人感知到的与实际的BMI之间的关系，以及医学专业人员事先识别肥胖的影响。通常，自我认知研究仅调查与当前体重的关系，而本研究的重点是体重差异的自我认知。
采用统计方法评估对墨西哥2006年全国健康与营养调查（ENSANUT）的回答。对BMI在13至60之间的成年人进行了分类问题和数字评定量表自我认知问题的回答测试。使用线性回归分析了性别差异以及医学专业人员对肥胖的识别情况。
结果表明，无论当前BMI和性别如何，医学专业人员的言语干预都会独立于实际BMI增加感知到的BMI，但不一定会使被识别出的肥胖者对其BMI估计更准确。被识别出的肥胖者的回答更高，平均自我认知发生了变化。在BMI＜35的范围内，观察到感知到的BMI随实际BMI呈线性增加，但如果能准确感知体重差异，增加率远低于预期。
肥胖和超重的墨西哥成年人不仅低估了自己的体重，而且无法准确判断体重变化。例如，就自我形象而言，想象中增加5公斤实际上要少得多。结果发现，医疗保健专业人员对肥胖的识别并没有提高判断体重的能力，而是成为被识别出的肥胖者判断自己体重的新锚点，这表明即使是那些已经减肥的被识别出的肥胖者，也认为自己的体重比实际体重更重。我们认为，这些结果可以用两种认知偏差来解释：自利偏差和锚定偏差。
