In yoga, food is broken down into three types of foods. Foods that have an impact on weight gain or sleepiness are called Tamasic or heavy. Foods that over stimulate or lead to restlessness and fatigue are called Rajasic. Foods that result in a sentient being, one that is able to balance his body and live in harmony is called Satvik food.Yoga therefore encourages you to live in and eat Satvik foods as much as is possible.
The bulk of satvik foods are made of ground foods or foods that are grown close to the ground and are therefore able to absorb the nutrients from nature. Organic is therefore highly preferred over genetically modified or pesticide filled food. The satvik diet encourages the eating of fruits, dairy products, nuts, seeds, oils, ripe vegetables, legumes, whole grains, and non-meat based proteins. There is some controversy around the consumption of dairy with regard to whether it should form a part of your diet or not.
Above all, it is recommended to eat in moderation and allow your mind to exercise restraint on how much you eat. Satvik foods are also freshly cooked and simple with minimal use of spices. There is a strong emphasis on using unprocessed foods and cooking at home. While it obviously was not specified in ancient Vedic texts, satvik foods do not include foods cooked in a microwave or re-heated before consumption. Similarly foods that use preservatives, emulsifiers, coloring agents, wax or polish, foods with a strong odor or foul smell or food that has been deep refrigerated are not preferred in a Satvik diet.
Satvik living is as much as lifestyle much like being vegan and so you have to decide whether this works for you or not. The ancient texts say that you become what you eat and therefore recommend eating a satvik diet.