Firstly look for restaurants that serve healthier options. Unfortunately in India eating salads out is not highly recommended. There are now a few that are getting conscious. Never eat too many varieties when eating out. Choose a main dish that does not have a refined food like white bread or white rice as a base (even simple soups are full of white flour). Do not eat fried foods. Choose sauteed or grilled food. Eating stir-fried vegetables is one of the healthiest options. However, eating out is rarely healthy because the refined base ingredients used like the salt sugar oil are all not healthy (read basic guideline). And usually the cheapest ingredients are used. It is best to find ways of being able to have home cooked meals (even a good whole grain sandwich is better than eating out) or start an organic restaurant !