The Yoga Diet is one the Five Principles of Yoga. You will soon notice that eating properly will aid your health and make you feel fitter and cleaner. The Yoga Diet is a perfect complement to Yoga Exercise. Despite the fact that the Yoga Diet is not a Diet in the common sense of the word, you will probably loose considerable weight by just eating only healthy foods. Even if you do not want to become a vegetarian, we fully recommend anyone to follow these basic Yoga Diet rules as it will make you feel so much better.
The Introduction
In the unmanifested universe, energy has three qualities, known as Gunas, that exist together in equilibrium: Sattva (purity); Rajas (activity, passion, the process of change); and Tamas (darkness, inertia). Once energy takes form, one quality of the three predominates. Thus on an apple tree, some fruit is ripe (sattvic), some ripening (rajastic) and some overripe (tamastic). But no matter what quality prevails, an element of each of the other two will always be present as well - parts of the apple will be in all the different stages. The Three Gunas encompass all existence, all actions.
Sattvic Food

Sattvic Diet is the purest Diet, the most suitable one for any serious student of Yoga . It nourishes the body and maintains it in a peaceful state. And it calms and purifies the mind, enabling it to function at its maximum potential. A Sattvic Diet thus leads to true health; a peaceful mind in control of a fit body, with a balanced flow of energy between them.

Sattvic foods include:
cereals
wholemeal bread
fresh fruit and vegetables
pure fruit juices
milk
butter and cheese
legumes
nuts
seeds
sprouted seeds
honey and herb teas
Rajastic Food
Foods that are very hot, bitter, sour, dry or salty are Rajastic. They destroy the mind-body equilibrium, feeding the body at the expense of the mind. Too much Rajastic food will over-stimulate the body and excite the passions, making the mind restless and uncontrollable.

Rajastic foods include:
hot substances, such as sharp spices or strong herbs
stimulants such as coffee and teas
fish
eggs
salt and chocolate
Eating in a hurry is also considered rajastic
Tamastic Food
Tamastic Diet benefits neither the mind nor the body. Prana, or energy is withdrawn, powers of reasoning become clouded and a sense of inertia sets in. The body's resistance to disease is destroyed and the mind filled with dark emotions, such as anger and greed

Tamastic food includes:
meat
alchohol
tobacco
onions
garlic
fermented foods such as vinegar
stale overripe substances