Don't judge a food by its GI score
30 May 2016
There are limits to the glycaemic index, argues leading nutritionist Dr Rosemary Stanton.
Low GI foods are commonly mistaken for being a healthier alternative to foods with a high glycaemic index, she says.
Contrary to popular opinion, she says low GI foods are unlikely to increase satiety (the feeling of fullness) and there is little convincing evidence a low GI diet will help with weight loss.
“The glycaemic index (GI) of foods is useful for people with diabetes, especially when choosing a single food, but it’s not necessarily a marker of healthy foods,” Dr Stanton writes in The MJA.
Judging foods by their GI also gives a tick to those that do not fit with dietary guidelines, she warns.
The most obvious example is sugar sprayed with molasses to reduce the GI. Other unhealthy low GI choices include pure fructose, ice cream, potato crisps, and many cakes and chocolate biscuits.
“Having a low GI does not make potato crisps healthy, Nor does it mean that cakes or biscuits made with pure fructose or low GI sugar are somehow less damaging to teeth or waistlines,” she writes.
Furthermore, Dr Stanton argues there is scant evidence a low GI diet is effective for weight loss. Positive results tend to come from short-term studies or have used healthier low GI foods, she says.
“It’s worth reading the actual underwhelming results before accepting some of these [weight loss] claims.”