There are a number of grains that are considered whole grain but that do not contain wheat. Below is a short list or some of the most popular.
Brown rice or wild rice
For most people who don’t have a wheat/gluten allergy or intolerance, whole wheat grains are healthy and part of a balanced diet and there is no reason to avoid them. Before you start this new pattern of eating, consider if this is sustainable for you. Most restrictive diets that promise weight loss do not actually result in sustainable weight loss and can be detrimental to your health.
You may find it helpful to talk to a dietitian about your goals and they can work more closely with you and direct you!