Most of the time is about ignorance, but even if you know Sugar is not good (Parent wrongly assumes just refined sugar is the problem) it will be very difficult to see where is contained. There are many names for &quot;Sugar&quot; and hidden in different ingredients, like HFCS. 
<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;High_fructose_corn_syrup" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;High_fructose_corn_syrup</a>