I am a scientist specialized on metabolism and genetics.


Forget the idea that weight is something objective, specially our own weight... or our children's.

In 10 seconds? Most of us have a wrong perception of our own body weight, underestimating it when we are overweight and overestimating it if we are underweight, and this misperception has an impact on how we see ourselves, how we manage our weight and on our quality of life.

So if I am obese I may not see it? Indeed, less than 10% of obese people correctly identify themselves as being obese, while most are satisfied with their estimated weight, and some even see themselves as being underweight. And we have this misperception not only with our own weight but with our children’s too.

How does this affect us? Having a correct estimation of one’s weight is believed to be a crucial factor for engaging on behavioral changes that lead to weight loss. This is particularly important with parental perception of their child’s weight because parents tend to underestimate the weight of their child allowing unhealthy behaviors that will have heavy consequences on the child’s future weight and health.

And do we also overestimate our weight? Yes, particularly teenage girls, who see themselves as overweight even if they have normal weight. And both teenage boys and girls have high body satisfaction if they are underweight, perceiving their weight as normal. This can lead to behaviors that maintain low body weight in adolescents, with negative health consequences.

So weight misperception is a bad thing? Not necessarily. In fact, it may even be beneficial. Surprisingly, misperception in the direction of “healthy weight” is associated with higher quality of life, lower future weight gain and fewer depressive symptoms. It appears that knowing that we are overweight or obese may lead to lower self-esteem because of the fat stigma that exists in our society.

The bottom line is that we see ourselves differently of how we really are, but if this is good or bad is still to be determined.


The prevalence and practice impact of weight bias amongst Australian dietitians

Abstract: This study explored weight bias amongst Australian Accredited Practising Dietitians (APDs) and the effect of client weight status on dietetic practice.Participants were 201 APDs, recruited using purposive sampling. A self-administered questionnaire, the fat phobia scale (FPS), was completed to assess explicit weight bias. Participants were then randomized to receive either a female within the healthy weight range or female with obesity, accompanied by an identical case study for a condition unrelated to weight. Participants assessed the client based on data provided, provided recommendations and rated their perception of the client.Mean FPS scores indicated mild fat phobia. However, dietetic practice was significantly affected by the client's weight status. Dietitians presented with the female with obesity assessed the client to have significantly lower health and were more likely to provide unsolicited weight management recommendations. In addition, dietitians rated the client as less receptive, less motivated and as having a lower ability to understand and sustain recommendations.The contribution of this study is the exploration of how weight status may impact dietetic practice including assessment, recommendations and perceptions of the client. Dietitians may practice in a manner that represents or could be perceived as negative implicit weight bias, despite the explicit FPS assessing only mild fat phobia. Further research to understand the extent of the problem and how it impacts client outcomes and to test possible solutions is required.

Pub.: 17 Nov '16, Pinned: 30 May '17

Is Underweight Associated with more Positive Body Image? Results of a Cross-Sectional Study in Adolescent Girls and Boys.

Abstract: The aim of the study was to investigate the relationship between body image and prevalence of underweight, normal weight, and overweight in adolescents. The study included 1702 girls and 1547 boys, aged 14-16 years, who completed questionnaire assessing body satisfaction. The participants' BMI status: underweight, normal weight or overweight was determined on the basis of BMI cut-off values. Results revealed that more girls (p < .001) showed low body satisfaction (44.8%) and fewer girls (p < .001) had high body satisfaction (17.6%) compared to boys (28.5% and 29.0%, respectively). A two-way ANOVA revealed a significant interaction between BMI status and gender on body satisfaction F(2, 3243) = 4.10, p = .017, η2 = .003. In boys, body satisfaction was higher in normal weight and underweight in comparison to overweight individuals (p < .001). Underweight girls presented higher body satisfaction than those who were normal weight and overweight (p < .001). Our findings indicated that, in relation to gender, BMI status can be associated with different body satisfaction in adolescents. This should be taken into consideration when designing programs aimed at obesity and disordered eating prevention and body image improvement. Due to the fact that underweight girls and boys have high body satisfaction, this can lead to behaviors that maintain low body weight in adolescents and in turn this may have negative health consequences.

Pub.: 10 Feb '17, Pinned: 30 May '17

Protective Misperception? Prospective Study of Weight Self-Perception and Blood Pressure in Adolescents With Overweight and Obesity.

Abstract: Underestimating one's weight is often seen as a barrier to weight loss. However, recent research has shown that weight underperception may be beneficial, with lower future weight gain and fewer depressive symptoms. Here, we examine the relationship between adolescent weight underperception and future blood pressure.Using data from the National Longitudinal Study of Adolescent to Adult Health, we obtained a nationally representative sample of 2,463 adolescents with overweight and obesity (students in grades 8-12 in 1996). We used multivariable linear regression to prospectively examine the relationship between weight self-perception in adolescence and blood pressure in adulthood (year 2008; follow-up rate 80.3%), controlling for age, gender, race/ethnicity, smoking, alcohol consumption, education level, household income, and body mass index. Additional analyses were stratified by gender and race/ethnicity.Youth with overweight/obesity who underperceived their weight had lower blood pressure in adulthood than those who perceived themselves to be overweight. The decrease in systolic blood pressure was -2.5 mm Hg (95% confidence interval: -4.3, -0.7; p = .006). Although the interaction by gender was statistically insignificant (p = .289), important differences appeared upon stratification by gender. Young men showed no significant difference in adult blood pressure related to weight self-perception. Conversely, in young women, weight underperception was associated with an average decrease in systolic blood pressure of -4.3 mm Hg (95% confidence interval: -7.0, -1.7; p = .002).Contrary to conventional wisdom, weight underperception is associated with improved health markers in young women. The observed differences in blood pressure are clinically relevant in magnitude, and interventions to correct weight underperception should be re-examined for unintended consequences.

Pub.: 19 Feb '17, Pinned: 30 May '17

The association between misperceptions around weight status and quality of life in adults in Australia.

Abstract: Limited evidence supports a possible association between a person's perception of their weight status and their quality of life (QoL). This study evaluates whether misperception around weight status is associated with QoL and the impact of gender on this association.A cross-sectional survey of Australian adults (n = 1,905 analysed) collected self-reported height and weight (used to estimate BMI), gender and QoL (described using the AQoL-8D). Participants reported whether they perceived their weight status to be 'underweight', 'healthy weight', 'overweight' or 'obese'. Misperception around weight status was categorised based on perceived weight status and self-reported BMI. Ordinary least squares regression was used to test associations between self-reported overall, physical and psychosocial QoL, misperception of weight status, and gender, across different BMI categories, after controlling for income, education, relationship status and health conditions.Compared to accurate perception, underestimation of weight status was associated with higher overall QoL for obese males and females and for overweight males. Overestimation of weight status was associated with higher overall QoL for underweight females and lower overall QoL for healthy weight males and females. The same pattern was seen for psychosocial QoL. Physical QoL was less sensitive to misperception than psychosocial QoL.Self-reported misperception around weight status is associated with overall, psychosocial and to a lesser extent physical QoL in Australian adults, although its role depends on BMI category and gender. Generally misperception in the direction of "healthy weight" is associated with higher QoL and overestimation of weight status by those who are of healthy weight is associated with lower QoL. Findings should be confirmed in datasets that contain measured as opposed to self-report height and weight.

Pub.: 23 Mar '17, Pinned: 30 May '17

Parental optimism about childhood obesity-related disease risks.

Abstract: Most parents believe childhood obesity is a problem for society, but not for their own children. We sought to understand whether parents' risk assessment was skewed by optimism, the tendency to overestimate one's chances of experiencing positive events.We administered a national web-based survey to 502 parents of 5-12 year old children. Parents reported the chances that (a) their child and (b) 'a typical child in their community' would be overweight or obese, and develop hypertension, heart disease, type 2 diabetes, and depression in adulthood. Respondents self-reported demographic and health information, and we obtained demographic and health information about the typical child using zip-code level census and lifestyle data. We used regression models with fixed effects to evaluate whether optimism bias was present in parent predictions of children's future health outcomes.Parents had 40 times lower adjusted odds (OR=0.025, P<0.001, 99% CI: 0.006, 0.100) of predicting that their child (versus a typical child) would be overweight or obese in adulthood. Of the 20% of parents who predicted their child would be overweight in adulthood, 93% predicted the typical child would also be overweight in adulthood. Controlling for health and demographic characteristics, parents estimated that their children's chances of developing obesity-related co-morbidities would be 12-14 percentage points lower those that of a typical child.Parent risk assessment is skewed by optimism, among other characteristics. More accurate risk perception could motivate parents to engage in behavior change.International Journal of Obesity accepted article preview online, 03 May 2017. doi:10.1038/ijo.2017.103.

Pub.: 04 May '17, Pinned: 30 May '17

Parental misperception of child's weight and related factors within family norms.

Abstract: Parental perception of their child's weight may be a crucial factor in parental ability for action with regard to their child's weight problem. This aim of this study was to investigate parental perception of their child's weight status and dietary healthiness, amount of food consumed and physical activity level and its related factors.A cross-sectional survey was conducted among children (Grades 4-6) selected by cluster sampling in two schools. Children were invited to participate in the measurements of anthropometry and their parents were asked to classify their child's weight and health behaviors.In total, 41.8% of parents misperceived their child's weight, of which 82% underestimated their child's weight, in particular regarding overweight or obesity. As parents of overweight or obese children underestimated their child's weight, around 65% were not concerned with their child's current weight and about becoming overweight in the future. Factor associated with underestimation of overweight children was not having a sibling, while among children with normal weight, the underestimation was associated with boys, lower body mass index (BMI), maternal employment and low household income. Furthermore, parents underestimating their child's weight were more likely to be optimistic about their child's dietary healthiness, food amount taken, and physical activity level than those with correct child's weight estimates.Findings show a high proportion of parental misperception of their child's weight status. Family-based weight control interventions will need to incorporate parental misperceptions of the body weight and health behaviors of their children.

Pub.: 24 May '17, Pinned: 30 May '17