Every day the media bombards the nation with concern over childhood obesity. More American children than ever before are developing health problems related to their eating habits and lack of exercise. The classroom is the perfect place to deal with this national crisis by speaking directly to the children. If children could become more aware of the fat in foods they eat each day, they could better control how much weight they gain or lose. The author wanted students to understand that all bodies need some fat, and that eating certain types of fat is healthy for the body, but eating too much of the wrong type of fat can cause the body harm. This article describes science lessons the author designed for her fourth grade classroom that aim to: (1) show students that all bodies need some fat, and that eating certain types of fat is healthy for the body, but eating too much of the wrong type of fat can cause the body harm; and (2) inspire students to think about their food choices and the effects these choices have on their body. When asked to connect what they learned from one experiment and what they already knew about "junk food," students began using science to understand the big picture. The activities allowed the students to experience the entire scientific process: creating a question, discovering an answer through experimentation, recording data on a chart and converting it to a graph, discussing their results with peers, and disseminating their findings to others. By the end of the lessons, the students understood that knowing the fat content of food allows them to make healthier decisions about how much and what kinds of food to eat. Further, students realized that they could use science to help them make choices that affect their lives. (Contains a list of 1 resource and 1 online resource.)