Caffeine is a Diuretic

• Caffeine takes water out of the system and people may lose additional water weight when taking caffeine pills, according to the Mayo Clinic website.
  
  

Suppresses Apetite

• Caffeine reduces a person's desire to eat, but the appetite suppressing effects of this substance do not last for a long enough period of time to determine if this effect of caffeine contributes to weight loss.
  
  

Binge Eating?

• Taking too many caffeine diet pills can lead to more stress, which can lead to binge eating, according to the Teecino website. Following the directions on the package prevents many of these problems, but people with anxiety problems may want to find a caffeine free weight loss supplement.
  
  

Calories Burned

• Caffeine sometimes causes a person to burn extra calories after consuming a product that contains the substance. The effect is not large enough to be a factor in additional weight loss.
  
  

Use Caution

• Consuming extra caffeine does cause a person to lose weight through the removal of extra water from the body. As long as a dieter uses caffeine in moderate doses, coffee, tea and diet sodas may help the dieter lose weight because of its diuretic effects. Caffeine should be used with caution as it can cause nervousness, irritability and insomnia.