In any case, there is nonetheless a good deal of evidence to indicate that modafinil is producing at least a portion of its wakefulness-promoting effects by acting as a DRI, or at least via activation of the dopaminergic system. In support of modafinil acting as a dopaminergic agent, its wakefulness-promoting effects are abolished in DAT knockout mice (although it is important to note that DAT knockout mice show D 1 and D 2 receptor and norepinephrine compensatory abnormalities, which might confound this finding), reduced by both D 1 and D 2 receptor antagonists (although conflicting reports exist),  and completely blocked by simultaneous inactivation of both D 1 and D 2 receptors.  In accordance, modafinil shows full stimulus generalization to other DAT inhibitors including cocaine, methylphenidate, and vanoxerine, and discrimination is blocked by administration of both ecopipam (SCH-39166), a D 1 receptor antagonist, and haloperidol , a D 2 receptor antagonist.  Partial substitution was seen with the DRA dextroamphetamine and the D 2 receptor agonist PNU-91356A , as well as with nicotine (which indirectly elevates dopamine levels through activation of nicotinic acetylcholine receptors ). 
During the pre-lunch period, participants had greater feelings of satiety after the egg breakfast, and consumed significantly less energy (kJ; +/- vs +/- , Egg vs Bagel breakfasts, p < ), grams of protein ( +/- vs +/- , Egg vs Bagel breakfasts, p < ), carbohydrate +/- vs +/- , Egg vs Bagel breakfasts, p < ), and fat +/- vs +/- , Egg vs Bagel breakfasts, p < ) for lunch. Energy intake following the egg breakfast remained lower for the entire day (p < ) as well as for the next 36 hours (p < ).
Untested alternative weight loss diets, such as very low carbohydrate diets, have unsubstantiated efficacy and the potential to adversely affect cardiovascular risk factors. Therefore, we designed a randomized, controlled trial to determine the effects of a very low carbohydrate diet on body composition and cardiovascular risk factors. Subjects were randomized to 6 months of either an ad libitum very low carbohydrate diet or a calorie-restricted diet with 30% of the calories as fat. Anthropometric and metabolic measures were assessed at baseline, 3 months, and 6 months. Fifty-three healthy, obese female volunteers (mean body mass index, +/- kg/m(2)) were randomized; 42 (79%) completed the trial. Women on both diets reduced calorie consumption by comparable amounts at 3 and 6 months. The very low carbohydrate diet group lost more weight ( +/- vs. +/- kg; P < ) and more body fat ( +/- vs. +/- kg; P < ) than the low fat diet group. Mean levels of blood pressure, lipids, fasting glucose, and insulin were within normal ranges in both groups at baseline. Although all of these parameters improved over the course of the study, there were no differences observed between the two diet groups at 3 or 6 months. beta- Hydroxybutyrate increased significantly in the very low carbohydrate group at 3 months (P = ). Based on these data, a very low carbohydrate diet is more effective than a low fat diet for short-term weight loss and, over 6 months, is not associated with deleterious effects on important cardiovascular risk factors in healthy women.