Background: It is alleged that the incidence of obesity, type 2 diabetes mellitus (T2DM), and metabolic syndrome (MetS) have sharply increased throughout the world. It is generally argued that increased consumption of a calorie-rich/ high-fat diet, lack of exercise, and sedentary-lifestyles are responsible, besides increasing age, gender, and obesity itself. But, certain authors argue that increased consumption of a carbohydrate-rich diet high in sucrose, fructose, and/or glucose is responsible for the increasing incidence of obesity, T2DM, and MetS. The same proponents also claim that these sugars cause cancers and other chronic diseases through ‘chronic low-grade inflammation’, besides directly. Some yet argue against these claims, causing an on-going raging international controversy, with strong implications for Malaysia.
Objective: The aim is to resolve this controversy through an appropriate literature-review.
Methodology: Literature from both sides, such as journal-articles, systematic-reviews, meta-analyses and booksummaries were reviewed, besides videos of lectures uploaded onto YouTube.
Results: Although here is observed for and against claims that sugar, especially sucrose and fructose, is an addictive, toxic-substance capable of causing chronic-diseases and, being the main cause of obesity, the evidence is overwhelmingly against such claims. Almost all of the studies for appear to have been done on rats and cell-lines, and not of an epidemiological-study nature. Even the nature of the metabolism of sugars claimed as conclusions from these studies is doubted by different studies/articles. The ACGIH categorizes sucrose as not classifiable as human or animal carcinogen. Current existing guidelines on dietary-sugar do not seem to meet criteria for trustworthy recommendations.
Conclusion: The evidence is overwhelmingly against claims that sugar causes chronic diseases, and that sugar is the main cause of obesity. There is a need for more epidemiological-studies.