There is not enough research to show that diabetes can be reversed in 30 days. However, WebMD states that Type 2 diabetes can be reversed by long-term changes in exercise and eating habits.
Look AHEAD, a study co-authored by the University of Alabama at Birmingham, showed that Type 2 diabetes could potentially be put into remission with diet and exercise. The study recruited 5,145 overweight adults aged 45 to 76 years with Type 2 diabetes. Participants were required to exercise for 175 minutes a week, limit calorie intake to 1,200 to 1,800 per day and attend weekly counseling sessions. Within a year, about 10 percent of the participants got off their diabetes medications completely.
The documentary. "Simply Raw: Reversing Diabetes in 30 Days" claims that a raw food diet can reverse diabetes in matter of days.The movie chronicles six diabetic cast members who agree to follow a raw food diet for 30 days. In addition, the movie includes interviews with Morgan Spurlock, who directed and starred in the documentary "Super Size Me," and the actor/activist Woody Harrelson. According to the documentary, all six patients made dramatic improvements. However, Science-Based Medicine states that the claims of the movie are based on the anecdotes of six individuals, which can not be considered as rigorous scientific evidence.