While the majority of adults worldwide consume at least some caffeine daily, mostly in the form of coffee or tea, abnormally high amounts of caffeine are usually limited to “fat-burning” supplements. When weight loss pill manufacturers include caffeine in amounts they’re rarely used otherwise, it’s likely to cause both short-term issues like dependence and jitteriness or, even worse, dangerous interactions with existing medical conditions or medications.
Larson-Meyer, D. E., Willis, K. S., Willis, L. M., Austin, K. J., Hart, A. M., Breton, A. B., & Alexander, B. M. (2013, June 8). Effect of honey versus sucrose on appetite, appetite-regulating hormones, and postmeal thermogenesis [Abstract]. Journal of the American College of Nutrition, 29(5), 482–493. Retrieved from http://www.tandfonline.com/doi/abs/10.1080/07315724.2010.10719885