Why We Get Fat: And What to Do About It
Simple carbs spike up blood sugar through the roof, the body responds by dumping insulin, the insulin causes blood sugar to be sequestered in fat and muscle cells (as intended), but if the dump is large it may overshoot and the blood sugar falls through the floor. Aka "sugar crash". The crash will of course make you crave food again, the same simple carb kind. Vicious cycle.
This sort of see-saw messes you up real bad. So I was told 
I have since then thrown in intermittent fasting as well. I fast 22 hours a day, work out at the end of the day, and then go home and eat 1kg of steak/lamb. I think intermittent fasting is worth adding to any diet, vegan or otherwise.
 Book was printed in 1956, so copyright may have expired. There's PDFs online. Here's a link to Stefansson's Wikipedia entry: https://www.amazon.com/Why-We-Get-Fat-About/dp/0307474259
When I first encountered the idea that we do not get fat from eating too much and that calories weren't responsible, I thought it ludicrous—the body can't disobey the laws of physics! Thermodynamics! But after seriously thinking about the idea, I realized Taubes was providing a far more complete understanding of metabolism. The human body doesn't run on calories, it runs on food. Yes, we can easily learn the caloric content of food, but that's largely irrelevant. What's important is how food affects the body, not its raw energy content. I see this misconception time and time again, especially among smart people who like to reduce the human body to merely a physical machine, often ignoring the whole biology thing.
I think the hormone theory of obesity is correct and I think these studies will prove it. But even if they show otherwise, this type of research is long overdue and we all stand to benefit from the results.
: : http://youtu.be/ywRV3GH5io0
You should read Why We Get Fat: and what to do about it by Gary Taubes if you get the chance. It really goes into detail about the rise of shitty science in the 60s and the issue of weight/obesity moving from the realm of biochemistry to the unregulated world of psychiatry.
Gary Taubes in his books like Good Calories, Bad Calories(very sciencey and extremely researched and aimed towards doctors) and Why We Get Fat(same info more approachable) does a good job of explaining the interactions in the lipid system and debunking this idea or calories in = calories out, particularly in regard to body fat.
There is a much more complex system in regard to testosterone, triglycerides, and insulin than this simple idea follows.
>Building upon his critical work in Good Calories, Bad Calories and presenting fresh evidence for his claim, Gary Taubes revisits the urgent question of what’s making us fat—and how we can change.
>He reveals the bad nutritional science of the last century—none more damaging or misguided than the “calories-in, calories-out” model of why we get fat—and the good science that has been ignored. He also answers the most persistent questions: Why are some people thin and others fat? What roles do exercise and genetics play in our weight? What foods should we eat, and what foods should we avoid? Persuasive, straightforward, and practical, Why We Get Fat is an essential guide to nutrition and weight management.
You got it. If more people realized what you just discussed, we would flip this whole thing around. It's the sugar and the simple carbs that has brought us here. The demonization of fat. If we replaced sugar and simple carbs, with fats and protein we would literally solve this without having to struggle so much. My family and I have lost about 25% of our body fat doing just that. What people don't realize is how long fat keeps you satiated and you're no longer using will power to not eat, you simply don't have cravings to overcome. It also isn't as simple as calories in calories out. One example is protein calories. 1/3 of calories from protein are used in metabolizing them...there is much more science to it,the reason it isn't what we're being taught is because there is big money lost if we demonize sugar the way we have tobacco, but that's what we need... Anyway there's obviously much more to it.. If you'd like to learn more check out this book that explains it with science and research in a simple to follow way.