Vegetables and fruits are typically low in calories and filled with essential nutrients, making them an essential part of any healthy diet. Getting more of these nutritious foods may help lower your risk for heart disease, high blood pressure, digestive problems, vision problems and cancer. They don't supply all of the essential nutrients, however, so it isn't a good idea to eat only fruits and vegetables for any significant amount of time. Check with your doctor before attempting such a diet to make sure it would be safe for you. Although a two-week all fruit and vegetable diet might not result in long-term consequences, the longer you follow this type of diet, the more likely you'll be to experience nutrient deficiencies.