Not to be confused with 5 a Day for humans, the Rabbit Way to 5 a Day is quite different. Fruit and vegetables are to a rabbit what sweets and chocolate are to us...
We humans are recommended to eat 5 portions of fruit and vegetables every day. For some of us this may be a struggle but for a rabbit it would be heaven on earth. Most rabbits tend to have a sweet tooth and adore anything which is relatively high in sugar, such as bananas, carrots, apples and so on. They are to rabbits what sweets are to us and it is our responsibility as rabbit owners to limit their intake of these foods. Too many of them and, as in humans with sweets, the waistline will expand while the teeth deteriorate.
This is not to say that we cannot feed our rabbits these foods but they should be seen as treats only. Not only will this help your rabbit, it will also help your wallet - treats sold in petshops for rabbits tend to be high in sugar and low in nutrition, not to mention expensive, so feeding natural treats instead is a good idea.
Treats are an important part of a rabbit's life and have a variety of uses. For example, they can be used when training your rabbit to simple voice commands, as an encouragement to overweight or lazy rabbits to exercise more (by hiding them from the rabbit), as a way of encouraging a nervous rabbit into a carrier or cage, or simply as a reward for a well behaved house rabbit.
In terms of proportion, the main bulk (approx. 80%) of a rabbit's diet should always be a good quality hay. Pellets (approx. 10%) and green, leafy vegetables (approx. 10%) are fed alongside this daily. Natural treats can be fed in small amounts e.g. one slice of banana at a time.