Many single-serving food products provide more food than is advertised, according to a new study by US Agricultural Research Service scientists in Beltsville, Maryland.

The scientists wanted to evaluate the reliability of weights stated on single-serving-sized commercial food products to see if researchers could depend on what was printed on labels in place of determining actual weights. Products sold as single portions, such as serving-sized boxes of cereal, packaged desserts or canned fruit, are commonly used as part of controlled diets prepared for research studies.

Three researchers at the ARS Beltsville Human Nutrition Research Center (BHNRC) conducted the study to determine the accuracy of label weights on 99 food items prepared for human volunteers during controlled feeding studies. Only 37 food items were found to be statistically accurate. Fifteen items were below weight, making them potentially out of compliance with federal guidelines. However, 47 products were found to contain more food than promised.

The government requires the food industry to meet guidelines for a minimum weight per package. These guidelines are meant to protect consumers from shortages in product weight.

The Agricultural Research Service is the US Department of Agriculture's chief scientific research agency.