Circadian Preference, Work Schedules, Adiposity and Eating Patterns among Adults in Tamil Nadu, India

Abstract

Evening chronotype has been associated with adverse dietary behaviours and metabolic health outcomes in adults. However, evidence linking circadian preference, social jetlag, and occupational work schedules with adiposity, dietary intake, and chrononutrition remains limited among Indian adults. This study examined these associations in 720 adults aged 25–50 years from Tamil Nadu, India. Data on adiposity, work schedules, circadian preference, sleep, diet, and lifestyle were collected using standardized measurements, established, and expert-reviewed questionnaires. Correlation analyses and multivariable linear regression examined associations between study variables. Higher rMEQ scores were independently associated with lower BMI (B = −0.240, 95% CI: −0.376 to −0.105; P < 0.001) and waist circumference (B = −0.660 cm, 95% CI: −0.991 to −0.329; P < 0.001). Social jetlag was positively correlated with diastolic blood pressure (ρ = 0.130, P < 0.001). Occupational schedules were associated with chrononutrition differences, including more frequent late-night snacking among night-shift workers (40.4%), later first meals and shorter eating windows among rotating-shift workers (P < 0.001 for both). Compared with day-shift workers, rotating-shift work and non-employment were associated with higher waist circumference (B = 3.321 cm, 95% CI: 0.374 to 6.268; P = 0.027; B = 3.376 cm, 95% CI: 0.424 to 6.328; P = 0.025, respectively). Energy and macronutrient intakes were broadly comparable across schedules, although selected nutrient differences were observed. Greater morningness was independently associated with lower BMI and waist circumference, whereas occupational work schedule was not independently associated with BMI. Occupational schedules were more strongly related to food timing than energy or macronutrient intake.