Your new diet lacks soluble fiber. Many popular diet regimens, such as gluten-free, paleo, keto, Whole30 and. Following a diet that doesn't contain much fiber can contribute to constipation. A person may not be getting enough fiber if they eat a lot of meat, dairy products, and refined carbohydrates, but don't eat a lot of vegetables, fruits, or whole grains.
Processed grains and their products, such as white bread, white rice and white pasta, have less fiber and can cause more constipation than whole grains.