Crystal Light is a sugar-free powder that adds flavor and color to water. It is low in calories (five calories per eight ounce serving) as it uses an artificial sweetener and flavoring. Crystal Light promotes weight loss because it encourages you to drink more water while keeping caloric intake down. Water can help you lose weight because it helps curb hunger and promotes healthy body function.

On the Other: Artificial Sweeteners May Hinder Weight Loss

Crystal Light is traditionally sweetened with the artificial sweetener aspartame. Some varieties now use sucralose. A study by the University of Texas Health Science Center (2005) showed that people who consume diet drinks regularly are at a higher risk to be overweight. Evidence shows that artificial sweeteners slow the metabolism and trigger overeating.

Bottom Line

The key to weight loss is burning more calories than you consume. Drinking Crystal Light in lieu of cola and high-calorie fruit juice can help you cut calories and lose weight. However, drinking pure water will not slow your metabolism or trigger overeating like beverages with artificial sweeteners, such as Crystal Light, can. Add a splash of lemon or lime to your water for added flavor without the chemicals.

Source:

Time: Can Sugar Substitutes Make You Fat?

Mayo Clinic: Artificial Sweeteners