The article is meant for those only who care a lot about their diet. Dr Sandria Goodwin of Tennessee State University in Nashville and colleagues have developed a portable tool that could help people to estimate the portion sizes of wedge-shaped foods like pizza, cake and pie. They have developed a modifiable wedge to determine portion size of triangular foods. Here is the complete analysis: They then compared the accuracy of the wedge against a ruler, having 320 people use both tools to estimate the portion size of a variety of foods, including three different-sized slices each of pie, cake and pizza. Participants viewed each portion for 30 seconds, after which it was removed. They were then asked to estimate its size using the adjustable wedge and then the ruler, and were also asked how confident they were in the accuracy of their estimate. Even using the tools, the researchers found, people frequently made inaccurate estimations of portion size. People tended to underestimate the size of “lower profile” foods like pizza and pie, while they overestimated the size of thicker foods such as cake. In one-third of cases, the wedge was more accurate than the ruler. People were more confident in their estimates with the adjustable wedge – even though these measurements were not necessarily more accurate – and said they preferred it to the ruler. “Because subjects were less intimidated when using the adjustable wedge, ruler-challenged clients may find the adjustable wedge a helpful tool,” the researchers conclude.