Theoretically, i.e., if everything else is held constant, the replacement of a sugary product with an artificially sweetened product that yields no energy should result in the loss of weight. But people do not live in an everything-else-held-constant world. The theoretical potential for weight loss will be realized only if the artificially sweetened beverages are actually used in the right way.5 But “evidence that use of NNS [nonnutritive sweeteners] in free-living individuals results in improved weight loss or maintenance is lacking” (Mattes and Popkin 2009, 9).
