We are beings of matter comprised of trillions of atoms.
Sugar tastes good because the sucrose molecules interact with taste receptors on our tongues, those taste receptors send signals to the brain, that information triggers the pleasure center of your brain to release chemicals which make you feel good. That is, sweet things trigger the pleasure region of the brain, and the brain rewards us for doing so. It's not just sweet things, lots of things can trigger this response.
Why do sugars do this? Because the body needs sugar for fuel, when we eat food the nutrients in that food is broken down, enzymes and other biological processes break down and convert complex sugars into simple sugars which can then be used directly by the body. Eating simple sugar is basically a short cut, the body is instantly getting the sugar rather than deriving it from more complex chemicals such as carbohydrates.
We evolved from fruit eaters, fruit constituted a primary if not the primary food source for our ancestors, and so we have an evolutionary biological reason to like sugars: fruits contain lots of energy, body needs energy, brain tells body it has done good by getting that energy, and so eat more fruit. It's the opposite, in many ways, to the sour and bitter tastes, especially bitter which serves the opposite purpose. Many bitter compounds are poisonous or toxic, and thus having an early warning system--"eww! this tastes bitter!"--means we have a better chance not to poison ourselves from our food.
We aren't beings of light.
We are "energy", in the same way that all matter is "energy", depending on how we are defining "energy". The problem with the word "energy" is that it gets used to mean something it doesn't actually mean. Energy is work or force. It's not forms of various ethereal substance.
These atoms that comprise us really are what we are made of. We are dust, made of the same things this planet of ours is made from.
But we are animate matter, alive matter. And it is that quality of being alive that is special; and even more than that, we are living creatures that have the capacity for reasoning, we have rational minds, that makes us moral agents in the universe. In this we bear God's image and likeness, reflecting God's likeness not on the basis of our matter or form, but because we are relational, feeling, thinking, moral creatures.
The human person is not just homo sapiens, the thinking man; but is also homo liturgicus, the worshiping man.
-CryptoLutheran