When I am traveling I aleays cary home made food. Home made food is better than resturant food for its nutrition value and hygine. This also saves a lot of money. When I am traveling, I avoid snacking. Snacking consumes a lot of money. I also avoid expensive food, I always choose food items that are cheap, make me full and has nutritional value.
I think one of the most effective ways is to avoid eating at branded restaurants because the foods / drinks are will always be very expensive (no matter what you're going to eat or drink ).
When we were traveling one tip people gave us was eat where locals eat it's cheaper and tastier. You might as well enjoy the local flavors while traveling too. We got to eat at very good places and it was cheaper. I don't like to cook when on vacation, so it's a treat to eat out all the time. I like having a breakfast free hotel deals to save money. These days you can just research a little to see what's available for how much, so it makes eating where locals eat much easier now.
When traveling, food is probably the most expensive thing for tourists since we can't live without it, and people know it so they just raise the prices. So what I do, I bring my own home made food with me and get to save some money with it. But it's not the point really, to go somewhere and get the opportunity to try something new and resist it. So I also try some of the food out there too, which is nice.
You can save money on food in many ways some of the best ways are hidden in plain sight and people just don' t care or realize to know about. One way is hotel buffets which give their residents free breakfast or lunch depending on which hotel it is while the food may not be that good its still free and ok to eat. Another way is through buying at low cost convenience stores that are in the area which don't charge much for food which again is not good but it is not expensive and you can still eat it. Lastly another way is local food like street markets or vendors where they do not charge that much for food. While these option may not be all or the best you could use these when you are going on your trip to have inexpensive food.