Fruits and Vegetables form part of a balnced diet. They contain vitamins, minerals and other substances that the body needs to maintain health. Humans are omnivores and derive their nutrition from a wide range of food groups . Also fruits are good for the digestion as basically fruits are designed to be eaten, be digested to get the nutrition from the plant, then the seeds are passed out of the body to start a new generation of the parent plant.

Unlike many other simple sugars, fruit contains other important vitamins and minerals and most importantly, fibre all part of a healthy diet. It is also best to limit fruit juices as the amount of fruit needed to make it creates a higher sugar content and eliminates the fibre.

The sugar in fruits is in a form called fructose. It's a much less harmful form of sugar and is easily processed through the body. This is not to be confused with high-fructose corn syrup, which is an enhanced, cheap sugar derived from starchy vegetables, notably, corn. It does horrendous things to your blood sugar, causing it to spike, then drop hard.

The other answers regarding vitamins, minerals and fibre are correct. Sugar itself is not so much the issue. Rather it is the type of sugar, and the effect it has on the body. You will no doubt have heard of the 'Glycemic index'. Sugar is a part of a group of molecules called 'carbohydrates', which consists of many different types. What makes them different is their complexity. Starch is actually a very complex form of sugar, and with the right enzymes can be broken down into sugar. Glucose is the simplest form of sugar, and it is this particular sugar that the body uses for fuel. Any other form of sugar in the body is broken down into glucose to be used. This is where GI comes in. Different sugars take different times to break down into glucose and be absorbed into the body. Pure glucose has a Glycemic Index of 100. It is the benchmark against which all other foods are measured. A high GI food has sugar which is quickly absorbed into the body, causing a rapid rise in blood-sugar, and a corresponding spike of insulin. (Insulin is the hormone that controls blood-sugar levels. It is this hormone that insulin diabetics lack). Insulin lowers the sugar levels in blood. Hence a sharp spike in sugar will be followed by a plunge as the glucose is consumed by the body or converted by the insulin. A low GI food has more complex sugars which take longer to be broken down and absorbed. This results in a more steady release and absorption of these sugars. The blood-sugar level is kept more level by this steady absorption, and is sustained by the continued release as it is slowly broken down. It also requires less insulin to be produced to keep the blood-sugar levels down. Most fruit contain a sugar called 'fructose'. This form of sugar has to be broken down, and so has a lower GI than high glucose foods such as sweets and processed breads. The more processed a food is, the more its sugars are broken down. Common white bread is so processed that it is almost as bad as eating pure glucose. Multigrain or wholemeal bread has a much lower GI since the body needs to break down the unprocessed starches and fibre into glucose. The other thing is that most fruit are comparatively low in sugar compared to their levels of other nutrients. When you take into consideration that fruit and vegetables have the highest natural concentrations of vitamins, minerals and antioxidants of any food group (save nuts and legumes), then they are definitely worth including in your diet.

it might be cause its a different type of sugar