This diet is highly structured. Participants in the Zone diet are instructed that every meal and every snack should consist of 40% carbohydrates, 30% protein, and 30% fats. This produces what Sears considers the ideal ratio of protein to carbohydrate.articipants in the Zone diet are instructed that every meal and every snack should consist of 40% carbohydrates, 30% protein, and 30% fats. This produces what Sears considers the ideal ratio of protein to carbohydrate.