At home people sometimes cheat and eat with their hands, but in public this may not always be acceptable. There are certain times when eating with your hands is not only acceptable, but is expected.
Some foods were never intended to be eaten with a knife and fork, and doing so may be considered “wrong”. Such foods include pizza, chicken wings, fried chicken, french fries, ribs, and so forth. Of course eating such foods is often messy, so proper napkin use is a must.
Cheese on crackers, hors d’oeuvres, and the like are traditionally considered “finger foods” indicating a norm for eating them with your hands. This would also apply to such items as cookies.
Another type of food that should be eaten with the hands are breads, or foods served in bread. These foods include those when in the form of a burger, sandwich, hot dog or simply as buns, bread sticks, and garlic toast. The last three are often used to soak up gravy from the plate and as such hands are used.
Fruit is often eaten with the hands, particularly when served whole.
Some cultures eat with their hands. In the east Indian culture eating with the right hand is normal, and acceptable. It is a faster means of eating and is said to make the meal more sensual and enjoyable. Typically bread is served with the meal and is used to pinch the food, or scoop it up. When eating at an east Indian restaurant, dinner party, or so forth, eating with ones hand is not only acceptable, but expected, however you should only use your right hand.
Some North African foods, and Middle Eastern foods, are also eaten with ones hands, such as Hummus.
-Some Foods use Both-
Often times certain foods, such as shellfish, requires the use of both hands and utensils. Crab and lobster must be cracked open and then pried apart with ones hands, the use of a special fork will aid in retrieving the meat inside. The gesture of food to mouth still involves the fork.
-When Utensils are Not Provided-
Sometimes it is clear that utensils are not to be used when they are not made available, or are not provided, such as when at carnivals, or specialty parties. In this case just go with the flow and have fun.
Remember when eating with the hands it is important to always wash both hands before, and after, eating. Make good use of the napkin, and watch for social cues from other diners if unsure on how to eat a certain food item correctly.