 Obesity is a major public health problem. Observational data suggest that drinking water is associated with a healthier weight. Indeed advice to drink extra water to help with weight control is widespread eight 8oz glasses or 2L of water a day is a common recommendation. The public spends billions of dollars on bottled water in the belief that it works and people are increasingly carrying water with them throughout the day. However, a systematic review of randomized controlled trials looking at the effectiveness of drinking extra water to help reduce weight or weight gain or produce changes in surrogate markers such as appetite or caloric intake undertaken by our group showed that currently there is an absence of reliable evidence to support the recommendation to drink water. 