Meda Dhatu — The Fat Tissue
Meda (fat/adipose tissue) is the fourth body tissue, providing lubrication, insulation, energy storage, and the foundation for hormonal regulation.
Meda Dhatu encompasses adipose tissue and the fats of the body. Its functions are lubrication of all body tissues and joints, thermal insulation, energy storage, and — as Ayurveda recognized — a relationship with reproductive hormones and the menstrual cycle. The concept of Sthaulya (obesity) in Ayurveda is sophisticated: it is not simply the accumulation of Meda but a disruption in Meda's metabolic processing, leading to pathological accumulation rather than healthy distribution. Ayurveda identified eight types of body builds (Ashtau Nindita Purusha — eight censured body types) of which obesity was considered most pathological because it impairs all other tissues. Modern endocrinology has validated Meda's hormonal functions: adipose tissue is now recognized as a major endocrine organ producing leptin, adiponectin, estrogen, and numerous cytokines.
Meda provides unctuousness to the body; its excess leads to the heaviest of all diseases.
The discovery that adipose tissue is a full endocrine organ — not merely a passive energy store — validates the Ayurvedic insight that Meda Dhatu has systemic regulatory functions far beyond simple fat storage.
Charaka Samhita