This article is from the Food Science FAQ, email@example.com (Paul E. J. King) with numerous contributions by others.
This term has no specific meaning. It is an invented label which
some people have applied to foods of which they disapprove. It has,
for example, been applied indiscriminately to all fast food and all
snack foods. It has also been applied to any food high in fat and/or
sugar (and so in calories) but low in other nutrients. However, there
is no evidence that such foodsare other than acceptable as part of a