Thin illusion: a cross-sectional study on normal weight obesity among adults in a subdivision of Northern Haryana

Background While body mass index (BMI) is widely used to assess obesity, it fails to detect individuals with normal weight who have excess body fat referred to as normal weight obesity (NWO). NWO is associated with an increased risk of cardiometabolic conditions despite a seemingly healthy BMI. South Asians, known to carry higher fat percentages at lower BMI levels, are particularly susceptible. Yet, population-based data on the prevalence and determinants of NWO in North India are limited. Objectives To estimate the prevalence and examine the determinants of NWO among adults in Kurukshetra, North India, using Asian BMI criteria and body fat percentage. Methods A community-based cross-sectional study was conducted from October 2022 to September 2023, involving 460 adults aged 20–60 years from urban (Shahabad) and rural (Thol) areas of Kurukshetra district, selected via multistage stratified random sampling. NWO was defined as BMI 18.50–22.99 kg/m² with body fat >25% in males and >30% in females, measured using an Omron body fat analyser. Data on sociodemographic, dietary, physical activity and sleep variables were collected using a pre-tested structured questionnaire. Associations were analysed using χ2 tests and multivariate logistic regression. Results NWO was identified in 24.6% of participants with normal BMI. The condition was more prevalent among females (27.6%) and increased notably with age, particularly after 40 years. Married individuals were more frequently affected. Protective factors included daily intake of fruits and vegetables, greater dietary diversity and moderate-to-high physical activity. Poor sleep hygiene, particularly prolonged sleep latency and short sleep duration, was also significantly associated with NWO. These findings suggest a hidden metabolic risk among individuals with otherwise ‘normal’ weight. Conclusion NWO poses a significant but under-recognised public health challenge. Routine screening should include body fat assessments alongside BMI to enable early lifestyle interventions and prevent non-communicable diseases.