Qi, your vital life energy, creates warmth, movement and flow in our bodies. When flowing smoothly, we have a sense of well-being. During childbirth, considerable amount of blood is lost reducing your Yang Qi energy, the warming, dynamic aspects of Qi. This imbalance of Yin Yang in your body causes you to being vulnerable to cold.
To avoid 'cold' invading your body, it is important to consume warm, easy-to-digest foods and keep yourself warm, especially your abdominals, back, feet and neck where cold is easily entered into the body. Remember, warm feet = warm womb.
The blends here are focused on replenishing Qi and blood. Qi and blood work hand-in-hand. Qi is necessary to build blood, and blood circulates the vessels of your body with Qi to nourish the organs to create Qi. Have I lost you there? The main point here is that you need nutrient-dense meals that are easily digestible to support your stomach. Your stomach and digestion must be strong to produce good quality Qi and blood. This will help your body build a stronger foundation for tissue repair, reduce water retention and absorption of nutrients.
Furthermore, in Chinese Medicine, blood is the foundation of breast milk and must be flowing well with Qi for your breasts to function in their new role. Your breast milk also carries Qi in it which makes it particularly nourishing for your newborn.