Dr. Mark Hyman

"Organic foods are certainly very helpful because they contain higher levels of nutrients and higher level of vitamins and antioxidants," Dr. Hyman says. "The most important thing is whether you're eating foods that are rich in phytochemicals. A bigger issue is whether or not you're eating a plant-based diet."

Of course, there are some individuals who Dr. Hyman recommends do not follow The UltraSimple Diet. They include those on medication for chronic illness, pregnant or nursing women, anyone under the age of 18, anyone who is underweight or malnourished, anyone with cancer, terminal illness, mental illness, hyperthyroidism, kidney problems, or anemia. As with all diet and fitness programs, consult with your physician before starting any new plan.

Once you've completed the seven-day program, you can continue on the plan for a longer period of time. Dr. Hyman says you can remain on The UltraSimple Diet for up to three months. At that point, you can slowly integrate other foods back into your diet and see how the body reacts. Dr. Hyman strongly suggests doing this every few days so you don't overwhelm your system. Keep a log of how your body reacts to different foods. Once you determine which foods make you sick and fat, then you'll know to avoid them.

If you are satisfied with the results after seven days, do not go back to your old way of eating. Reintroduce foods back into your diet based on Dr. Hyman's recommendations. Through trial and error, you'll be able to determine which foods your body is allergic to.

"The next step outlined is to reintroduce foods that are potentially allergic foods," Dr. Hyman says. "Identify those foods and keep them out of your diet if you're still feeling sick. The goal for is to have people see how good they can feel. Most people don't realize they're feeling bad until they feel so good.