The best way to cut a sandwich has been confirmed by science, Or are you a sandwich renegade who opts for eating the thing whole? The consensus view favours cutting sandwiches diagonally to form two triangles, although hard science to back this up is difficult to find. One hypothesis is that a triangle allows you to take your first two bites from the two 45° corners. These only have crust on one side and give faster access to the middle of the sandwich where the filling is most concentrated. After the corners have been tackled, you may have between one and three bites along the diagonal, which is crust-free and, depending on the size of the sandwich, may leave you with another smaller triangle.
Eventually, of course, each triangle is reduced to a single 90° nubbin of crust, but if you try this with a sandwich cut rectangularly, you’ll end up with two crusty corners for each half, instead of one. Another argument for triangles is that they’re neater to eat. Only children and cartoon characters take their first bite from the middle of the cut face, because doing so inevitably deposits mayonnaise or jam on the sides of your mouth.
Several studies have confirmed this phenomenon. It seems that triangles give you more sandwich filling per bite. A triangular sandwich has two 45° corners that allow you to bite much further towards the middle on your first two bites, where there is more filling. This is followed up by a perfect, crustless third bite as you take the space left in the middle. Bite number four is, of course, mostly crust, but
you can’t have everything!
Starting from one of the corners allows for a cleaner bite and the 45° angle of a triangle maximises the depth of the bite. Taking this to its logical extreme, we could cut a sandwich into four triangles that can be eaten in three neat bites. You often see this strategy adopted for children’s parties, but in my experience, children rarely eat the 45° corners first. When it comes to children’s parties, the optimal cutting strategy is probably to slice the crusts off altogether.