Vegetarian women show subtle changes in cellular health markers

By Vijay Kumar MalesuReviewed by Lauren HardakerJan 13 2026

A large study of Slovak university women finds subtle shifts in bioelectrical impedance markers among vegetarians, without clear evidence of health impairment or cause-and-effect.

Study: Associations Between Vegetarian Diet and Bioelectrical Impedance Parameters: Insights into Body Composition and Cellular Health in Young Adult Women. Image credit: Dragana Gordic/Shutterstock.com

In a recent study published in Nutrients, a group of researchers examined whether a vegetarian diet is associated with differences in bioelectrical impedance and fluid distribution in young adult women.

Why body weight alone misses cellular-level differences

Today, many young people report nonspecific sensations such as bloating or fatigue, even when their weight appears normal, raising important questions about what standard measures of body size may miss. More individuals are turning to plant-based diets, as evidenced by one trial, where 35 % of participants opted to transition to a vegetarian diet. This way of eating is known to lower the risk of heart disease, type 2 diabetes, and high blood pressure.

However, a scale alone cannot reveal what occurs at the cellular level. Bioelectrical Impedance Analysis (BIA) estimates body compartments. It provides Phase Angle (PhA), which is commonly interpreted as a marker of cellular integrity and membrane function, though it does not directly measure cell damage or dysfunction. It also measures the Extracellular Water (ECW)/Total Body Water Ratio (TBW), indicating fluid distribution. Further research is needed to establish a connection between dietary details and these markers.

How researchers measured diet, lifestyle, and body composition

The sample consisted of 647 Slovak women aged 18–30 years, primarily recruited from universities. In this study, 66 participants reported following a vegetarian diet for at least six months, while 581 reported an omnivorous diet. Participants completed a Slovak questionnaire adapted from the World Health Organization (WHO) STEPwise Approach to Surveillance (STEPS-WHO) 2014 tool. This questionnaire covered diet type, smoking, physical activity, alcohol use, and hormonal contraceptive use. Physical activity was divided into three groups based on weekly minutes of moderate or vigorous exercise.

Trained staff measured height, weight, waist, and hip circumferences, then calculated Body Mass Index (BMI) and Waist-to-Hip Ratio (WHR). Body composition was assessed using the InBody 770 with multifrequency BIA following standardized preparation rules. Outputs included Resistance (R), segmental Impedance (Z), and segmental Reactance (Xc); total-body Xc was derived from R and PhA. The device also reported Intracellular Water (ICW), ECW, TBW, Body Cell Mass (BCM), Fat-Free Mass (FFM), Fat Mass Index (FMI), and Fat-Free Mass Index (FFMI).

Researchers examined group differences and associations using Statistical Package for the Social Sciences (SPSS), employing comparisons, regression, and a Generalized Linear Model (GLM) mediation analysis. Models were adjusted for BMI, WHR, smoking, and activity.

Vegetarians show small but significant BIA differences

Vegetarian women made up 10.2 % of the sample and reported long-term adherence, averaging 5.93 years. They were slightly older than omnivores, but their lifestyle patterns were similar to those of omnivores. Smoking status was comparable, and physical activity categories were similar, with many women exercising only one to two times per week. Regular alcohol use and hormonal contraceptive use also showed no significant differences. BMI and WHR were alike, so the key findings were not influenced by size or central adiposity differences between groups.

Two BIA markers distinguished the groups. Vegetarian women had a lower PhA than omnivores (mean 5.06 vs. 5.23; p = 0.004). They also had a slightly higher ECW/TBW (0.382 vs. 0.380; p = 0.026). Although statistically significant, these differences were small in absolute magnitude. Measures related to mass and compartments, including R, Xc, ICW, ECW, TBW, BCM, FFM, FMI, and FFMI, did not show significant group differences.

Regression models, adjusted for smoking status, physical activity, BMI, and WHR, maintained the same pattern. Vegetarian status was associated with a small decline in PhA (standardized β = −0.094; p = 0.011) and a small increase in ECW/TBW (standardized β = 0.085; p = 0.028). Physical activity correlated with both outcomes; higher activity was connected with higher PhA and lower ECW/TBW. BMI and WHR were also linked to these markers. Higher BMI and WHR corresponded with higher PhA, while higher BMI and WHR were connected to lower ECW/TBW. Further adjustment for alcohol use and contraceptive use did not change the relationship with diet.

A GLM mediation analysis explored whether smoking or activity influenced the diet associations. Neither pathway reached significance for PhA or ECW/TBW, indicating that diet differences did not run through these lifestyle choices in this dataset.

In everyday terms, this study is significant because BIA readings are commonly used in gyms, clinics, and laboratories. Two women with similar BMI could still show different PhA or ECW/TBW values, which reflect differences in BIA-derived indicators of cellular integrity and fluid distribution rather than confirmed differences in health or performance. The clinical relevance of these small between-group differences remains uncertain, particularly given the narrow range of values observed in this healthy young population.

The study did not examine the effects of lower vitamin B12, zinc, iron, protein quality, or long-chain omega-3 fats, such as docosahexaenoic acid (DHA), as details of food intake or blood markers were not collected.

Vegetarian diets linked to descriptive BIA variations only

Among young Slovak women, a vegetarian diet was associated with lower PhA and higher ECW/TBW after adjusting for BMI, WHR, smoking, and physical activity. These differences based on BIA represent descriptive variations in indicators of cellular integrity and fluid balance, rather than evidence of cellular damage or impaired physiological function.

However, the cross-sectional design does not demonstrate cause and effect. The study did not measure diet quality, supplement use, or nutrient levels, leaving the reasons for these patterns unclear. Research that tracks intake, biomarkers, and habits over time can shed light on whether these shifts are important for health, performance, or risk.

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