The obesity epidemic in the United States and other countries worldwide has been compared to the effects of tobacco and alcohol in terms of the extent of its negativity on the health of individuals. Epidemiological surveys confirm that 65% of U.S. adults are overweight or obese. The consequence of remaining obese or overweight lies in a myriad of psychological and physical health conditions which contribute to overall morbidity and mortality. For as many health problems that obesity contributes to there are numerous diets that attempt to remedy the epidemic. However, it is not known which of them and to what extent are they effective, partly because commercial weight loss results are not usually scientifically tracked making assessments of effectiveness difficult. This study evaluated the effectiveness of a 5-week commercial weight loss plan in three distinct venues; a conventional setting consisting of a comprehensive store front clinic, an emerging venue which is an online Internet program, and a novel venue which is set in a retail pharmacy. Results indicated that the conventional weight loss program produced the largest reduction in weight (averaging 12.16 pounds compared to 7.09 pounds for the emerging group and 8.31 pounds for the novel group), body mass index (averaging 2.00 for the conventional group compared to 1.17 for the emerging group and 1.34 for the novel group), and waist circumference (averaging 2.10 inches for the conventional group compared to 1.70 inches for those in the emerging group and 1.52 inches for those in the novel group), but with no significant differences between the novel and emerging groups. In addition, multiple regression results indicated that (a) older participants lost less weight (β = -.18) and had smaller body mass index reductions (β = -.19) than younger participants; and (b) females lost less weight (β = -.36), had smaller body mass index reductions (β = -.24), and smaller waist circumference reductions (β = -.10) than males. Supplemental analyses indicated that the percentage reduction in weight loss for most participants was substantially below the 10% value that is typically considered to be clinically relevant only 3.9% of the conventional group, 1.1% of the emerging group, and 0.0% of the novel group attaining this goal.