They always say, "too much of anything is bad for you".
There was also a popular Journey song with the line, "Why could something good can hurt so bad".
Both of these lines can answer your question, yes. No matter how good something tastes, or even no matter how healthy it can be, it isn't good for you to keep living off the same thing.
An example: Water is one of the healthiest foods or drinks that you can put into your body and it is very important to stay hydrated, drinking at least 6 - 8 glasses of water a day. However, you can overhydrate by drinking way too much water, and this can cause water intoxication, which can actually be fatal. This is rare, but can certainly happen. While water is healthy, it can kill you. The two quotes above in my answer certainly relate to this.
Now, let's answer your white chocolate question. White chocolate has a good amount of calcium in it, but that's about the only positive. There are several things about white chocolate that are not good for you.
- High calories.
- VERY high amount of sugar, which is really not good for you. A high sugar intake can really worsen your diet.
- A high amount of fat, especially saturated fat. Saturated fat can cause a lot of health problems, one of them including weight gain. If you are someone who is trying to lose weight, stay away from white chocolate!
- Along with short-term health affects, there are also negative long-term health affects associated with high saturated fat consumption. If you eat foods high in saturated fat (such as white chocolate, of course), it increases the chance of heart disease and diabetes as you get older.