“Central obesity, low levels of good cholesterol, high levels of bad cholesterol, high triglycerides, and poor appetite control have been linked to consuming high amounts of high fructose sweeteners,” says Dr Ritika Samaddar, chief dietician, Max Healthcare, Delhi.
Unlike glucose—another natural sugar —that can be absorbed by every cell of the body, fructose is broken down only in the liver, where it causes fat synthesis. “Once fructose is in the liver, it can provide glycerol, the backbone of triglycerides (fat), and increase fat formation,” says Dr Samaddar.
And as Dr Arpita Hirani, dietician at PD Hinduja Hospital, Mumbai, puts it, “Fructose gets converted to fat faster than any other sugar”. It can also make us fat in other ways too, such as by inhibiting the formation of leptin, a hormone that warns the brain about the presence of fat in the body, thus controlling appetite and regulating energy intake. But with fructose inhibiting its secretion, obesity is close. 

Is it safe to consume fructose in fresh fruit juices, which have no preservatives or other chemical substances in them? “Fruits juices may not have fibre, but they do have minerals and vitamins. So, they aren’t a no-no. Even honey has a lot of fructose and no fibre and yet its many health benefits outweigh the negative effects of fructose,” says Dr Samadar.

There’s no medically recommended daily intake for fructose, but it’s always great to have four to five fruits, say doctors.