Claims that sugars, particularly fructose, are toxic have achieved widespread attention in recent years, but Dr Lisa Te Morenga of Otago University’s Department of Nutrition says the evidence to support these claims has been sparse. On the other hand, studies funded by the sugar industry have found no relationship between sugar intake and obesity. “These used constant energy intake, so the low sugar diets had other sorts of calories instead,” Te Morenga says.
The World Health Organization (WHO) commissioned Te Morenga to lead an international study to get to the bottom of the issue. She concludes that sugar reduction has a “small but significant” effect on body weight. On average, participants in the studies Te Morenga reviewed lost 0.8 kg when they reduced their sugar intake, while those that increased sugar consumption gained 0.75 kg. Study length varied from 2 weeks to 8 months, with an average of around 3 months. Te Morenga says that longer programs showed greater effects.
The review, published in the British Medical Journal, investigated free sugars added by manufacturers or present in honey, syrups and fruit juices. Consequently the sugars naturally present in fruit or milk were not included.
Te Morenga says while there may be no calorific difference between the different types of sugars, those in fresh fruit come with plenty of other nutrients...
