Final answer:
Food is considered a normal good with low but positive income elasticity of demand, meaning as income rises, the demand for food increases but at a decreasing rate, since food consumption doesn't scale indefinitely with income.
Step-by-step explanation:
The income elasticity of demand for food, such as daily calories consumed, generally exhibits a positive but relatively low elasticity. As income increases, people do consume more food, but there is a limit to how much can be consumed, and this is a basic need that does not change dramatically with higher income. We categorize food as a normal good since the demand typically increases with income, but at a decreasing rate, reflecting a low but positive elasticity. Unlike luxury goods or non-essential items, the consumption of food does not keep pace with income increases to the same extent, as people tend to spend their additional income on other types of goods and services. Therefore, extra income results in a less than proportional increase in demand for food overall.