Absolutely - sugar and all kinds of processed foods are so harmful, both from a dietary and a behavioral standpoint. Our foods have so many preservatives in them so that they have a long shelf life - translated: the bugs won't eat them and they don't spoil, but WE eat them and we DO spoil! These foods don't break down on the shelf, and they don't break down in our bodies. As a consequence, we are undernourished even if we are overfed. We have epidemic rates of diet-related diseases, most of which originate in the gut - many cancers, diabetes, constipation, heart disease, and more - and then migrate to other areas which are unable to get necessary nutrients.
If you are reducing sugar, the main thing to eliminate is not a little plain cane sugar or stevia (plant-based) now and then, but high fructose corn syrup (highly processed). So read labels. Dr. Oz and many others say to eliminate "enriched flour" - which is basically flour which has been stripped of all of its nutrients, and then had a couple of things added back in - it's still a shadow of its former self. So, eliminating high sugar cereals is a good thing, but if you are replacing it with bread or pasta made from "enriched" flour, you're not accomplishing anything. White flour turns to sugar pretty quickly, and it changes the body's blood sugar levels. You want to move to the darker alternatives - whole wheat bread & pasta, brown rice, etc. Corn is pretty much all sugar anyway - hence the corn syrup problem. A few drops of real maple syrup on a whole wheat pancake or waffle gives us some nice sweetness without a high fructose corn syrup with a little maple flavoring, for example.
The idea is to avoid foods that contain in their first 5 ingredients: corn syrup or high fructose corn syrup, enriched flour, sugar, salt and partially hydrogenated oil/fat (trans-fats). The sugars and white flours break down very quickly, increasing the blood sugar levels, but they don't sustain us and keep our energy up over a long period of time, which causes blood sugar levels to drop again. Yo-yo effect.
An exception would be something that has just a few ingredients - so Triscuits, for example, which only consist of whole wheat, soybean oil, and a little salt (only 3 ingredients) are better for your child than crackers with 15 ingredients (some questionable) but salt is lower on the list and not in the top 5. Soybean oil, like olive oil and canola, is a healthy fat, and we need those.
You will be adding to your child's nutrition and improving his/her dental health.
Does this help?