Not sure I've ever seen David answer here.
The book is clear on this. Fructose is a problem because your body does not know how to deal with it. Dextrose, your body knows how to deal with, but it's still the case that high calorie foods will make you overweight if you eat too much. So, the book says that dextrose based sweets should be a treat, not a staple. How much you choose to allow is up to you. The more dextrose based sweets you eat, the more calories you are eating, with obvious results. However, you should find that unless you continue to eat past being full because you want to 'pig out' on sweets, that if you have a ton of sweets, you will just find you're still full the next day.
Short version - have your eyes open to the fact that what you're eating is not great for you, but it's going to be a ton better for you than if you used sugar, mostly because your appetite control should work, if you listen to it, and stop you from eating too much, or keep you full afterwards for longer than usual.