I am a chef by profession and I tend to eat a lot of fast food because it's just a lot more convenient. Can this put me at a risk of gastric infection? What should I do to prevent it?
Yes, eating fast food has higher risk of food poisoning since the locales and the personnel may not be hygienic.
It all depends on how well the food is cooked and how safely the food is handled by those who cook the food and handle or serve the food.