The taste receptor for sweetness, T1R2/R1R3,1 can detect sugar at a concentration as low as about 1 part in 200, whereas some bitter substances can be detected in the range of a few parts per million, perhaps explaining why most individuals prefer foods with high sugar content but little bitterness. However, this innate preference for sweetness does not necessarily lead to obesity or other diet-related diseases because sugar-containing foods in their natural form tend to be highly nutritious. For instance, an 8-oz apple contains beneficial vitamins, minerals, and phytochemicals but fewer calories than a 2-oz portion of bread. Most fruits elicit a high level of satiety relative to calories ingested due to their low-energy density, high-fiber content, and low glycemic index.2