The COVID-19 pandemic has had a significant impact on human health and has led to social isolation and health implications. In order to optimize public health, it is important to understand the role of social and behavioral sciences, including dietary patterns and lifestyle changes. This study aimed to identify the effect of lockdown on dietary patterns and its association with Body Mass Index (BMI) and lifestyle changes in the older Indian population (aged 60 and above).The study was conducted using an online web-based Google form and 674 participants took part over a one-month period. The k-means algorithm was used to identify non-overlapping dietary patterns and logistic regression was employed to determine the factors associated with changes in dietary patterns. Three dietary patterns were identified: pro-healthy, constant, and unhealthy.During the study, 33.1% of the participants decreased their physical activity while 61.6% increased their screen usage. 26.7% consumed a pro-healthy dietary pattern, while 61.9% consumed an unhealthy dietary pattern. Women reported lower consumption of the pro-healthy pattern (23.8%) and higher consumption of the unhealthy dietary pattern (64.5%) compared to men (30.6% and 58.3%, respectively). Adherence to the pro-healthy dietary pattern was positively associated with age. Participants with a lower BMI were less likely to consume a pro-healthy dietary pattern [AOR: 0.02; CI: 0.01, 0.2]. Those who increased their physical activity were more likely to follow the pro-healthy dietary pattern [AOR: 6.49; CI: 0.76, 55.76]. Those who had less sleep [AOR: 10.22; CI: 1.97, 52.92] and more screen time [AOR: 7.61; CI: 3.28, 17.62] had a higher risk of following an unhealthy dietary pattern.The lockdown had a significant impact on dietary patterns and was associated with unhealthy lifestyle outcomes among older Indian adults. From a public health perspective, promoting awareness of healthy dietary patterns and promoting healthy lifestyles through educational programs is a priority. [ABSTRACT FROM AUTHOR]