People(and incredibly dieticians) still hang on to the "Calories-in calories-out" as we are engine burning food. Sugars(and most carbs convert to sugars) are responsible to 1.Cellular degeneration: https://en.wikipedia.org/wiki/Advanced_glycation_end-product 2.Diabetes type 2(key factor) https://en.wikipedia.org/wiki/Diabetes#Type_2 3.Severe, heroin-level addiction https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2235907 4.Brain degeneration and cognitive decline https://www.ncbi.nlm.nih.gov/pubmed/15082091