A growing number of people are unable to shed those extra pounds despite strict diet regimes and long hours of workout. Evidence shows that the toxins in the environment could be playing the spoilsport. They modify the body's physiology and make it difficult to lose weight. While the West is waking up to the complex linkages between chemicals and obesity, realisation is yet to dawn on doctors and researchers in India. Vibha Varshney, Dinsa Sachan and Sonal Matharu report on the new trigger for obesity and the way out