March 2017 Blog Post

Background

Evidence suggests that lesbian and bisexual women are at a higher risk for being overweight/obese compared to heterosexual women. This is a major risk factor for chronic health conditions such as T2DM, hypertension, and heart disease. A previous cross-sectional study indicated bisexual women more likely to skip breakfast and engage in unhealthy weight loss behaviors (laxatives, diet pills, bingeing). Another study found lesbians over 50 years of age less likely to meet recommended 5 or more fruits and vegetable servings per day. Living in rural or urban settings is also a possible contributing factor to overweight/obesity in this sexual minority.

Objective

To examine sexual orientation differences in diet quality intake among 26-67 years old in a longitudinal Nurse Health Study to determine if less-healthy diet quality is present among lesbians and bisexual women compared to heterosexual women which may contribute to weight status disparities in sexual minorities

Methods

A Nurse Health Study held in the United States surveyed 517,000 women through a biennial questionnaire mailed out with a follow-up rate of 93.6% between 1989 and 2011. A total of 926 lesbians, 415 bisexuals, and 98,317 heterosexuals participated in the questionnaires. Dietary measures were calculated from a food frequency questionnaire administered every 4 years which included diet quality (measured using Alternative Healthy Eating Index-2010 and Dietary Approaches to Stop Hypertension). Sociodemographic factors were also measured to determine those factors and the effects on weight. Outcome data was analyzed in 6 waves every 4 years. Sociodemographic characteristics were assessed using the bivariate Wald X² (for unchanging factors such as age, race) while age-adjusted Wald X² was used for changing factors (region of residence, rural living status). When examining the sexual orientation and dietary intake measures, multiple measures were used. Age-standardized means were estimated for all food intake measures. General patterns of key dietary intake patterns were examined (calories consumed, total diet quality). Repeated measures analyses were used in testing for differences in dietary measures by sexual orientation groups. Analyses were conducted with SAS software with a significance level of .05.

Results

Overall diet quality of participants increased with age. Diet quality was lower among women living in rural rather than urban regions. Both lesbian and bisexual women had higher diet quality scores (Alternative Healthy Eating Index-2010) than heterosexual women. This difference became smaller as participants grew older.

Conclusions

Lesbians and bisexuals reported higher diet quality compared to heterosexuals. Irrespective of sexual orientation, diet quality was lower during younger years and gradually improved as women aged. With existing research regarding lesbian and bisexual women’s disparities in overweight and obesity, further research needs to be done to determine other influences on this sexual orientation and weight, such as physical activity, sedentary behaviors, disordered eating behaviors, and stress in weight management. 

Continuing Education Article:

VanKim, Nicole A. et al. Dietary Patterns during Adulthood among Lesbian, Bisexual, and Heterosexual Women in the Nurses’ Health Study II Journal of the Academy of Nutrition and Dietetics , Volume 117 , Issue 3 , 386 - 395

Supplemental Article:
W.C. Willett, L Sampson, M.L. Browne, et al. The use of a self-administered questionnaire to assess diet four years in the past Am J Epidemiol, 127 (1) (1988), pp. 188-199.