You’re doing fine. Keep the fruit, but be somewhat selective of the kinds of fruit you eat. Most fruit has a relatively modest to low glycemic index (GI) and in many cases has a much lower GI than vegetables made up of complex carbohydrates.
The problem with the advice you have been given is that it’s half wrong and half right. This kind of information can really muddy the waters. Unfortunately, in the nutrition world, there are way too many ‘half knowledgeable’ experts too willing to share their half-knowledge.
Fruit is made up of simple carbohydrates and vegetables are typically complex carbohydrates. But the glycemic index (the measure of how the carbs affect blood sugar levels) varies significantly for both fruits and vegetables. By gaining a better understanding of the glycemic index of various foods you’ll be able to structure a diet that will allow you to take advantage of this knowledge to confidently build lean muscle.
Here’s an example: an apple has a GI of 58. This is very modest and will have a steady blood glucose effect. A cup of long grain white rice (a common food on the bodybuilder’s menu) has a GI of 109. This is extremely high and will cause a sharp rise in blood glucose levels. Here you have a simple carbohydrate that has a much less effect on increasing blood sugar than a complex carbohydrate.
The above information would certainly indicate that long grain white rice would have a much greater chance of promoting fat gain than the simple carbohydrates from an apple.
The lesson to be learned here is that the differences in carbohydrates go far beyond simple and complex. It’s how these carbohydrates affect blood sugar that tells the real story. Stick with low glycemic fruit and you can have your fruit and eat it too.