In 2013 I travelled three months backpacking around Nepal, India, Thailand, Sri Lanka (former Ceylon) and Vietnam. I always like to absorb the local culture wherever I go, but this time, because I was a bit more concerned about my health, because I was planning to travel alone, stay at the cheapest and shabbiest guesthouses, eat mainly local food at local restaurants or in the streets, and move around visiting shabby old little villages where hygiene habits were bad.
From all, my biggest concern was India, where I was planning to stay at Shirdi, Aurangabad and Varanasi (Benares), because of the negative feedback I had had from friends that always (or too often) get food poisoning when they travel there. This was my second time to the country, but my first time alone and in a wilder way.
I did all I planned to do and experimented all the foods I was curious about, and ate and drank regularly at street-stalls. Here are some tips I followed and that helped me not to get sick a single time: