Metta Tantra

In order to have true Metta we need to start with ourselves. We cannot have unconditional love for others if we do not have it for ouselves. This is the way it has always been taught.
We cannot have the desire for others to be "Free from Anger. To be Healthy, Happy and Content", if we are unhealthy.
Thus giving ourselves proper exercise, nutrition and rest is the beginning of being Metta. There is no point in attempting to develop Metta for ourselves if we insist on ignoring the very thing that carries us through this lifetime, which is of course, the body.
That decision to give yourself an absence of junk food, to give up smoking, to exercise properly and gaining a gorgeous physique is the first and most important act of Metta that you will ever do. There is an overlap between a body that is healthy and feels good and the ability to develop deep Metta for all beings.
Recollecting the power of giving yourself health is a blissful meditation. Acknowledging the wholesomeness of a proper diet and exercise, the skillfulness of it, brings Bliss into our meditation. The affirmation that what we are doing is absolutely right is what causes the Bliss to arise. When we know that the way we are living is an act of Metta towards ourselves we can then deepen it on our meditation cushion.
 A healthy body is also the perfect and required vehicle for Bliss in Dhammic Sex. Dhammic Sex is, when engaged in properly, an event that requires fitness and stamina. Bliss during Dhammic Sex is a gateway pleasure to Bliss during Metta.
We can make the Bliss, the Jhana that arises during Metta meditation an offering to the Buddha, Dhamma and Sangha. And thus the circle is completed. We cultivate healthy bodies as the basis for Metta, the Metta is an offering to the Buddha, the Buddha taught us to have Metta for ourselves. Without healthy bodies, the feedback loop, the circle is broken.
Go and have Metta for yourself by hiking 20 km.