When you start meditating, you have to keep your body clean. Why do you have to purify your body? Mathew 9:17 in the Bible states, “You do not put new wine in an old wine bag.” Why? The old wine bag is already stretched. Therefore if you out new wine, which is still fermenting, the gas pressure will increase and the bag will burst. The wine bag is likened to the body. The wine corresponds to the descent of spiritual energy. You must make your body like a new wine bag to prepare it to receive higher energy. Unless you purify your body, it will get sick. You will have kundalini syndrome that may manifest as insomnia, chronic fatigue, skin rashes, hypertension, overheating of the body and other symptoms.
Physical purification includes proper diet, physical exercises and breathing exercises. When you do spiritual practices, it is very important that you do not eat pork. If you take a look at pork clairvoyantly, it is extremely dirty. You may eat some meat, but not too much.
You also have to avoid eating fish with no scales such as eels and catfish because clairvoyantly they look dirty. If you can become a vegetarian most of the time, it is even better.
Exercising is important. This removes old use up energy and allows spiritual energy to flow into the energy body and physical body with less resistance. This will prepare the body for spiritual illumination or samadhi. When you keep your body clean and healthy, it can withstand a greater amount of higher energy.
Reference : Achieving Oneness with the Higher Soul. Master Choa Kok Sui.