Can anyone tell me what can i do to avoid constipation on a diet?

Avoid Constipation: One must consume adequate amounts of fluids, consume fruits and vegetables high in fiber content, limit "white" carbohydrates (white bread,, rice, potatoes, etc.), limit alcohol, and exercise regularly to avoid constipation. Bulk laxatives (Citrocel, Metamucil, etc.) may sometimes be helpful. If you continue to experience constipation, you should contact your physician, who may suggest colonoscopy

Water & fiber: It is essential you get enough water. You want to be drinking 80-100 ounces of water each and every day! If that is too boring, you can use no calorie flavor enhancers like Crystal lite or the squirt in types. Then make sure you are consuming lots of fresh and raw vegetables and low calorie fruits like apples, pears. Popcorn is also good on a diet and a good source of fiber. Also eat whole grains!

Fiber and water: Increasing fiber intake combined with adequate free water is the basis of constipation prevention, furthered by avoiding binding foods including dairy, bananas, starches, etc.