Self-perception of weight gain also appears to be significantly influenced by race, ethnicity and contraceptive methods.
Race/ethnicity and contraceptive use have been linked to accurate self-perception, with black women and DMPA (a birth control drug) users more likely to correctly perceive weight gain.
Despite popular belief about women's weight concerns, young women commonly fail to recognise recent gain of as many as 11kgs – putting them at risk for cardiovascular disease and other obesity-related conditions.
In a study published online and in the March issue of the Journal of Women's Health, University of Texas Medical Branch (UTMB) researchers found that a significant number of women evaluated at six-month intervals did not recognise recent gains in weight.
Link between contraceptives and weight gain
Overall, nearly one-third and one-quarter of women did not recognise gains of approximately 4.5 and 8.8kgs during a six-month interval, respectively. However, black women and DMPA users (depot medroxyprogesterone acetate, commonly known as the birth control shot) were more likely to recognise weight gain than their counterparts.
This is believed to be the first study to explore the accuracy of self-perception of recent weight gain. The findings build on a growing body of UTMB research on actual weight gain and awareness of weight among reproductive-aged women, with particular focus on the links between contraception use and weight gain.
Researchers surveyed a sample of 466 women with an average age of 25. Approximately 37% of the subjects were Hispanic, 35% non-Hispanic white and 29% non-Hispanic black women. Roughly 39% of the women used DMPA, 36% used an oral contraceptive and 25% were non-hormonal contraceptive users.
Ethnicity and race determinants in weight gain
Every six months over 36 months the women completed a symptom checklist that included questions on whether they felt they had gained weight. The researchers also evaluated data on height, BMI, physical activity and whether or not the women had borne children, among other potential correlates.
"We were surprised to find that race and ethnicity are determinants of accurate recognition of weight gain, predictors that have never before been reported," said lead author Dr Mahbubur Rahman, MBBS, PhD, MPH, Assistant Professor in the Department of Obstetrics and Gynaecology.
He notes that further studies using detailed measures that include cultural, psychological and perceptual aspects of weight change in women are needed to explore this relationship.
Overweight people think they are normal weight
Regarding the finding that DMPA users are likelier to recognise weight gain, Rahman believes the finding may be attributed to the fact that DMPA has been widely reported to be associated with weight gain and that users may be engaging in more mindful and continuous weight monitoring.
"In prior studies, we've reported that one-quarter of reproductive-age women who are overweight or obese consider themselves to be normal weight. Misperception of actual weight coupled with inaccuracies in self-perception of weight gain is a threat to the success of obesity prevention programs," said Rahman. "Changing health behaviour depends on patients understanding susceptibility to a health problem."
Rahman suggests women weigh themselves regularly so that they realise significant changes. He adds that this research, though not based on a random sample and therefore not necessarily representative of all women, gives clinicians a point of discussion when counselling reproductive-age women about obesity and weight loss.
(Eurek Alert, January 2012)
Fat people in denial