Dietary habits are one of the most conservative elements of culture and one of the most difficult to trace. Most nineteenth-century Americans believed that a healthy diet was an ample diet. The health fanatics did make inroads into American foodways, but they had no firm knowledge of chemistry, which underlies concepts of good nutrition. It was once suggested that there are two basic factors governing human diet: humans eat what they can find from their environment and given a choice, they eat what their ancestors ate. Social status is an important factor in food selection. Traditional societies controlled the consumption of high-status foods by forbidding their consumption by those deemed unworthy for reasons of gender, age, and family or clan. A society can broaden its diet beyond what can be produced in the local environment if technology is adequate to transport food in an edible condition at a reasonable cost.