Fruit is the only food nature has intentionally given us for eating. This is from a purely fruitarian
point of view, although this statement does have its arguments.
Fruits are a 'delivery package' for propagating seeds, so that the plant may spread its progeny, or 'offspring' (that makes it sound almost endearing). But nature made the delivery package so visually appealing (except for ugly fruit), fragrant, delicious and nutritious for a reason. You see, in the nature, the animals (incl. us humans) have a symbiotic relationship with the plant kingdom. This relationship is beneficial to both us and the plants. The plants need for their seeds to be scattered beyond their immediate vicinity. This ensures that the seeds will be introduced into a wide variety of environments, some of which will harbour ideal environmental conditions for the growth of that pretty, generous (scheming) plant.
Plants evolved their fruits, as a fleshy covering over their seeds, with a twofold purpose, where animals are concerned. First, the colours, fragrances, and tastes are meant to attract the animals to eat them. Second, it would not make sense in this symbiotic relationship between plants and animals for the animals to be poorly nourished; eventually they would become unhealthy and unable to scatter the seeds for the poor little plants.
So instead, the plants concentrate vital nutrients in the fruits with which they attract animals. It is in their own best interest to do so! The survival of the entire animal kingdom is dependent upon this process, for even the carnivores ultimately eat plant eaters, who eat plants. So you can see, the continued health and existence of both plants and animals are dependent upon this symbiotic relationship. The very best thing you can do for the environment, is to eat plentifully of the fruits that nature gives you. You could almost say it is our duty to do so.
They are also the only food that upon being eaten, does not cause a life form to die, or interfere with the process of reproduction, either of plants or animals. This is good stuff for karma whores.
I saw this slogan once, it was pretty lame: "Be cute, eat fruit!" except i think that fruit is cute :) Again, apart from the ugly fruit.