But its inclusion sparked protests from Honey New Zealand, which defended it as part of a natural diet.
Other readers contacted the Herald to express their concerns about artificial sweeteners.
Professor Molan said honey's nutritional benefits compared with its high energy content meant it should only be used as a sweetener.
But it was wrong to think of honey as the same thing as sugar.
"In general [honey] has a a low glycaemic index ... and lesser effect on raising blood sugar levels than refined sugar does."
In 2007 Professor Molan was involved in a study where rats were fed for a lifetime on diets which had the same amount of protein, sugar and fat as contained in a typical New Zealander's diet.
Some rats were fed honey in place of sugar.
"There was a very significant difference in weight gain. The rats got quite obese on the typical New Zealand diet, but not with the honey replacing the sugar."
He and a colleague are seeking funding to examine honey's effect on appetite.
"People tend to overeat to quite a large degree with sugary foods, but I've never seen anybody having more and more honey. Something like one piece of toast with honey, and that's enough."
He said the continued popularity of soft drinks with sugar despite the availability of sugarless varieties showed people were driven by the desire for pleasure and satisfaction.