The recommended diet for a student of yoga is a simple and wholesome vegetarian one, made up of natural foods that are easily digested. It keeps the body vital and healthy, and the mind calm and free from restless thoughts. Processed and tinned foods are to be avoided when possible.
 

In yogic philosophy, our diet affects far more than our physical well-being. Our vital energy, mental capabilities, and emotional health are all influenced by the food that we eat. The practice of meditation, postures, and breathing exercises is directed towards bringing the mind and the body into harmony. Eating the right foods is an important element in achieving this goal. Foods that are beneficial to us are said to be Sattvic, or pure. Impure foods that can upset our physical, emotional, or intellectual balance are identified as being in the categories. Tamasic (stale or rotten) and Rajasic (stimulating). You should avoid these foods.

Avoid tamasic foods
Foods that are stale, tasteless, unripe, over ripe, or putrified are Tamasic. They poison the body, sap our energy, and dull the intellect. Tamasic foods include meat and fish, mushrooms, and foods that have been frozen, preserved, tinned, over-cooked, or re-heated. Foods that have been fermented, such as vinegar, are Tamasic, as are all drugs and alcohol. Eating too much is also considered to be Tamasic.

Avoid Rajasic Foods
Onions and garlic, tobacco, eggs, coffee, tea, chillies and other strong spices, and foods that are sour, acid, or bitter are all Rajasic. Chocolate, white sugar, white flour, and most prepared and convenience foods are also Rajasic to a lesser extent. All these substances excite the passions and over-stimulate the mind, making it difficult to control. Eating too fast and eating too many combinations of foods is also Rajasic.

Choose Sattvic Products
Sattvic foods from the ideal diet, being nourishing and easy to digest. They create new energy and a clear, calm mind, enabling us to use all our mental, physical, and spiritual talents. Sattvic products include cereals, fresh fruit and vegetables, natural fruit juice, milk butter, beans, honey, and pure water.

Stop Smoking
Yogic philosophy identifies two impure categories of foods-Rajasic (over-stimulating) and Tamasic (Stale or rotten). Tobacco is both giving up smoking eliminates toxins from the body and helps you to achieve a calm mind and body.

Avoid Caffeine
Caffeine is considered to be Rajasic, as it is powerful stimulant. It causes the mind to be over-active and gives the body artificial energy. It can also disrupt your natural sleeping pattern, impairing your ability to relax. If you cut out tea and coffee from your diet, you will find that meditation becomes easier.