Two dispartate observations to add a little spice to this thread.
One can indeed eat locusts, they are nutritious and calorific . As a survival technique eating fresh maggots taken from a rotting carcass is also quite sensible (70 calories per ounce) , though weight for weight , the termite is an excellent nutritive assemblage.Larvae , grasshoppers , beetles and grubs are edible but one must avoid anything hairy, brightly coloured or smelly (spiders, ticks caterpillars).Worms are top notch but must be purged first.I will not be advocating this diet for delegates at the UK meeting.
So one may conclude that a savvy hermit might indeed live off dew (by dragging a light garment over grass and wringing the moisture out) and locusts, for a while at least. If St John had lived off Locust beans (they bear his name as a commonplace), he would have had a purged bowel and they probably would have killed him by dehydration.
I thought I would cross check my early Islamic sources for any "tradition" of refined sugar use (Iman Qayyim Al-Jawzlya 1292 CE onwrds), the learned scholar mentions frequent exhortations for the faithful to use honey but no doctrinal mention of sugar .Hakim Chisti in his commentary on Ibn Sina (Avicenna- collector and annotator of Roman and Greek treatises in the 9th C CE), rather brusquely says " white sugar should be banished from the home forever" and honey substituted for any culinary purpose .
The modern difficulty with refined sugar is its superabundance and addictivness, the fast rise and consequent sharp slump in blood sugar levels are not good:
http://www.chetday.com/bloodsugarinsulin.htm
heres an amusing straightforward summary telling you not to fill your veins with maple syrup!
Slow burn carbs from oats and the Roman Bread (spelt-coarse and varied endosperm) are a much better bet.