As the prevalence of obesity and type 2 diabetes have increased, more and more Americans increasingly turning to sugar substitutes in the hope of aiding weight loss. Some people believe that the use of these sugar substitutes can actually stimulate appetite and so may increase calorie intake making them of no value for those wishing to limit their calorie intake and lose excess body fat. However, data from controlled clinical trials do not support this belief.A recent study looked at the impact of sweetening a pre-load snack with stevia, aspartame, or sucrose on ad libitum calorie intake and measures of satiety and hunger. ¹ The researchers had all the research subjects consume the same breakfast after an overnight fast. They were then given a snack of tea, crackers and cream cheese with the latter being sweetened with one of the three sweeteners 20 minutes before they ate both lunch and dinner. The snacks containing the sugar substitutes each contained 203 fewer calories than those sweetened with sucrose. However, despite the higher calorie intake with the sucrose sweetened snacks compared to those sweetened with stevia or aspartame the subjects largely failed to compensate for the reduced calorie snacks by eating more at lunch or dinner. As a result at day?s end the subjects ended up eating an extra 301 and 330 kcal on the day on the sugar sweetened snack day than the stevia and aspartame test days. Despite consuming significantly fewer calories on the days they consumed the snacks sweetened with stevia or aspartame compared to sucrose-sweetened snacks, the subjects reported no differences in hunger or satiety ratings on all three test days. The results of this study, and earlier work, suggests that the use of sugar substitutes may be useful for lowering calorie intake.This study also showed that compared to sugar both sugar substitutes tended to lower both blood sugar levels and insulin levels after meals. This is not too surprising given the higher calorie and carbohydrate intake when sugar was consumed. However, despite similar intake of calories and carbohydrate on the stevia and aspartame days this study also showed stevia intake also lowered postprandial blood sugar and insulin levels more than aspartame. If this result can be confirmed it suggests stevia might be a preferable sugar substitute in those with diabetes.By James J. Kenney, PhD, RD, FACN1. Appetite 2010;55:37-43