Amid poor air quality in the national capital, doctors warned that the air pollutants, besides causing respiratory and cardiovascular issues, can also lead to weight gain, contribute to rising obesity rates, and also affect hormonal health.

The air quality in Delhi-NCR on Friday morning was reported to be in the 'very poor' category with a thin layer of smog engulfing the region. According to the Central Pollution Control Board (CPCB), Delhi's average air quality index (AQI) at 7.15 a.m. remained at 371. In seven areas of Delhi, the AQI level remained above 400 and between 450. The AQI was 410 in Anand Vihar, 411 in Bawana, 426 in Jahangirpuri, 402 in Mundka, 410 in Nehru Nagar, 402 in Shadipur, and 413 in Wazirpur. "Air pollution can affect weight gain by altering metabolism and can also affect hormonal health.

Air pollution causes metabolic disorders that can lead to weight gain. It can also cause inflammation which leads to obesity," Dr. Shailly Sharma, Senior Consultant and Associate Director, Obstetrician and gynaecologist, at Cloudnine Hospital, told IANS. "Air pollution can precipitate sedentary behaviour because it can cause certain respiratory symptoms like coughing, and shortness of breath, which can restrict physical activity and precipitate weight gain. It also increases insulin resistance, leading to weight gain and obesity," Sharma said.

Recent studies show that prolonged exposure to air pollution which contains particulate matter, nitrogen dioxide, and carbon monoxide, could lead to systemic inflammation and metabolic disturbances -- key in weight gain and obesity. A meta-analysis published in BMC Public Health in July found that air pollution can impact metabolic function by influencing inflammation in fat tissue, increasing oxidative stress, and altering individual dietary habits.

Breathing toxic air affects immune function and breathing pathways. This raises inflammation markers and increases oxidative stress. Dr. Vikas Mittal, Pulmonologist and director, Department of Respiratory Medicine, CK Birla Hospital told IANS that while there have been reports about air pollution affecting metabolism, leading to metabolic syndrome and obesity, the exact mechanism by which air pollution affects metabolism and hormonal health is not known.

"It could be because air pollution is an irritant and it can cause inflammation in the airways, and then leads to the secretion of inflammatory markers in the body and blood, which then affects various organs, and thus can lead to increase the change in the hormonal milieu and increase in the pro-inflammatory markers. This can lead to worsening of cholesterol, high blood pressure, and diabetes -- an important part of anybody having metabolic syndrome," the doctor explained. Studies have shown that long-term exposure to the pollutants in the air can disrupt hormones, causing imbalance and also leading to reduced conception rates and overall fertility.