Avoiding foods with added sugars surely you could survive. And I'd recommend avoiding them as well (though everything in moderation even moderation). When you say sugar is bad I suspect there will be some who will read such a thing and think to restrict their carbohydrate intake.Grains, rice, quinoa, lentils. Next thing you know they aren't eating enough calories and they are lethargic from a lack of glucose availability to the brain.