Yes I have 2 citations. This is an informal setting so I didn't go looking for them just now. One is the Berkeley Wellness Letter (a monthly publication associated with the Berkeley School of Public Health). There have been numerous references to keeping blood sugar from spiking and on the types of sugar that are worse for you, e.g., fructose. The other was from a Science podcast (or was it Nature?) on research on the "minimum" amount of exercise needed for health. In it they remarked that the longer sugar remains in your bloodstream the more cumulative damage it does to your arteries.

The minimum amount of exercise was, interestingly enough, 4 one minute sprints on an exercise bicycle, all out, as hard as you can go with no holding back. You can take a break after each sprint for a short while to catch your breath. Do this twice a week.

The test subject and controls were from time to time given a glass of glucose water, and the experimenters measured how long it took to clear the sugar from the blood.

The theory was this. The muscles have a ready reserve of energy and resist taking more from the blood unless you deplete some of it. Experiments indicate that the benefits of this "minimum" exercise program last for weeks after ceasing it.

This is not my field and I could not tell you why sugar in the blood is bad for you, or why certain sugars are worse. However, I understand that the Berkley Wellness Letter and Science/Nature are evidence based publications. Anyone not credulous can spend about an afternoon looking these things up, though a library is probably better than the internet because many relevant publications are not free.

p.s., a software engineer is a machine that takes caffeine as its input, and produces computer programs as its output.

Four hours is probably not enough lead time before sleep. I was taught years ago to never take caffeine after the traditional English "tea time." Tea time is around 4 or 4:30. For the last decade or more I've taken tea or coffee as I pleased up until 4 and then cut it out. Nobody in their right mind should ever drink soda/cola/pop. Forget the caffeine, it is the high fructose corn syrup, or the artificial sweeteners that cause problems. Diabetes in a bottle.

Perhaps he could give the money to his mother. Isn't she is supporting him on 30 quid a month? She would like to have the medal too, to show her friends over coffee. Mothers need things that sons don't.