GET IN THE KETO ZONE The Keto Zone is the point at which your body switches from burning carbs as fuel to burning fats as fuel. This transition is referred to as the Keto Zone. When you follow Dr. Colbert’s Keto Zone Diet you will burn fat, optimize cognition and improve energy levels. When diet isn’t enough, look to Dr. Colbert’s science based Keto Zone Nutritional System. The Keto Zone Nutritional System was developed to limit the time it takes your body to enter the Keto Zone, while also supplying your body with essential fats, protein and enzymes.