If your holidays are anything like mine, there is a lot of cooking going on, and that usually means a fridge full of leftovers. Sadly, aside from a turkey sandwich the day after Thanksgiving, most foods do not taste better the second day. Sure, you can blame it on refrigeration, reheating, or the fact that eating the same dish two days in a row does not excite the palate, but from a yogic point of view, the real problem with leftovers is that they have lost their prana, or "vital energy."

From an Ayurvedic perspective, foods devoid of prana inhibit digestion and impede well-being. "Basically, when you keep food for a long time, it takes more energy to digest it than you reap from the food itself," says Sarasvati Buhrman, PhD, Ayurvedic practitioner and co-founder of the Rocky Mountain Institute of Yoga and Ayurveda in Boulder, CO.

Perhaps worse, food that lacks prana lends nothing to the creation of the body's ojas (life energy). Traditionally, it is believed that the food we consume replenishes all the tissues of the body and becomes ojas in about a month. "Ojas permeates the entire mind/body complex and has a lot to do with resistance to illness," Buhrman says. So if you eat food that lacks prana, you may lack the resources for optimal health.

"The body's inability to metabolize foods that are not fresh results in the formation of ama, or toxic undigested material," adds Shubhra Krishan, author of Essential Ayurveda: What It Is and What It Can Do for You (New World Library, 2003). This substance clogs up the vital channels of the body, disrupting digestion and ultimately giving rise to everything from fatigue to disease. Since food begins losing prana the moment it's disconnected from its life source, it is important to create meals using only the freshest ingredients and to take care not to overcook them. Try not to cook meals ahead of time; if possible, make a few separate trips during the week to buy fresh produce. And instead of buying frozen, canned, or processed foods, reach for those that are still closest to their original state, such as fruits, nuts and freshly cut greens.

But cooking each meal from scratch is a luxury many of us can't afford. Besides, shouldn't modern refrigeration afford us some leeway in this area? "Maybe refrigerated food loses prana less quickly-we don't really know," Buhrman says. "I don't encourage people to cook food over the weekend and eat it throughout the week, but I think eating leftovers within 24 or 48 hours at the maximum is probably all right."