It is important to know about the energies of food because different energies act upon the human body in different ways and affect our state of health. If a person suffers from cold rheumatism and the pain is particularly severe on cold winter day, eating foods with a warm or hot energy shall relieve the pain considerably. Or if a person suffers from skin eruptions that worsen when exposed to heat, it is beneficial to eat foods with a cold or cool energy to relieve the symptoms.

To seek a balance in diet, we can define food as predominantly yin or yang. If you eat predominantly yin foods, your body will be capable of producing more yin energy – darker, slower-moving and colder. In contrast, eating predominantly yang foods will produce more yang energy – faster, hotter and much more energetic. It’s helpful to remember certain rules to determine the type of energy a food produces:
  

If it grows in the air and sunshine, it is probably yang;
If it grows in the earth and darkness, it is probably yin;
If it is soft, wet and cool, it is more yin;
If it is hard, dry and spicy, it is more yang.
Perfect for heating the body in winter time is black pepper, cinnamon, ginger(dried), chill pepper, mustard seed and star anise. Ginger is pungent in flavour, warm in energy and tends to move upward and outward.