I used to haul a big package of cookies and coffee into my office to get some serious work done, but over time, I noticed that sugar and fat make me really sleepy. Way back in 2010 I already wrote about that problem. I can eat a lot of crap without gaining much weight, and I often used that as an excuse to eat all those bad things, but in the end it makes me exhausted and lethargic.
When I came across this lecture on the effect of sugar -or better, high fructose corn syrup- I understood the deeper-lying issues with consuming processed (sugary) foods in large amounts (I put the sugary part in between brackets because virtually every food item from the central aisles of the grocery store that comes with a bar code has high fructose corn syrup in it, not just the sweet products).
Even though I don't support Dr. Lustig's quick recommendation that you should eat paleo (I'm more into whole foods plant-based eating), and don't support the conclusion some people (not Dr. Lustig himself) seem to draw when it comes to eating fruit, which contains fructose as well and thus "poison", this lecture is very interesting.
Take 90 minutes today while you prepare and have your dinner, and watch this instead of kitty videos: