Cross-sectional association of Toxoplasma gondii exposure with BMI and diet in US adults

PLoS Negl Trop Dis. 2021 Oct 1;15(10):e0009825. doi: 10.1371/journal.pntd.0009825. eCollection 2021 Oct.

Abstract

Toxoplasmosis gondii exposure has been linked to increased impulsivity and risky behaviors, which has implications for eating behavior. Impulsivity and risk tolerance is known to be related with worse diets and a higher chance of obesity. There is little known, however, about the independent link between Toxoplasma gondii (T. gondii) exposure and diet-related outcomes. Using linear and quantile regression, we estimated the relationship between T. gondii exposure and BMI, total energy intake (kcal), and diet quality as measured by the Health Eating Index-2015 (HEI) among 9,853 adults from the 2009-2014 National Health and Nutrition Examination Survey. Previous studies have shown different behavioral responses to T. gondii infection among males and females, and socioeconomic factors are also likely to be important as both T. gondii and poor diet are more prevalent among U.S. populations in poverty. We therefore measured the associations between T. gondii and diet-related outcomes separately for men and women and for respondents in poverty. Among females <200% of the federal poverty level Toxoplasmosis gondii exposure was associated with a higher BMI by 2.0 units (95% CI [0.22, 3.83]) at median BMI and a lower HEI by 5.05 units (95% CI [-7.87, -2.24]) at the 25th percentile of HEI. Stronger associations were found at higher levels of BMI and worse diet quality among females. No associations were found among males. Through a detailed investigation of mechanisms, we were able to rule out T. gondii exposure from cat ownership, differing amounts of meat, and drinking water source as potential confounding factors; environmental exposure to T. gondii as well as changes in human behavior due to parasitic infection remain primary mechanisms.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Body Mass Index*
  • Cross-Sectional Studies
  • Diet
  • Female
  • Humans
  • Male
  • Nutrition Surveys
  • Obesity / economics
  • Obesity / metabolism
  • Obesity / parasitology*
  • Obesity / physiopathology
  • Poverty
  • Toxoplasma / genetics
  • Toxoplasma / isolation & purification
  • Toxoplasmosis / economics
  • Toxoplasmosis / metabolism
  • Toxoplasmosis / parasitology
  • Toxoplasmosis / physiopathology*
  • Young Adult

Grants and funding

JC acknowledges support from the Alabama Agricultural Experiment Station and the Hatch program of the National Institute of Food and Agriculture, US Department of Agriculture (accession number 1023614). The funders had no role in the study design, data collection and analysis, decision to publish, or manuscript preparation.