Clearlight Infrared Saunas have been clinically proven to be a great tool for weight loss. A study at Binghamton University in NY using a Clearlight Premier IS-3 found, on average, sauna users lost 4% body fat using an infrared sauna for 30 minutes three times per week. Weight gain may not be tied to just diet and exercise. There is a recent study linking environmental toxins to weight gain.
In the medical journal, Environmental Health Perspectives, the recent article, Obesogens: An Environmental Link to Obesity, looks at the link between weight gain and our environment.
You can read the full article at the following link: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3279464/