The point of the DBAVT drawing is this: If you want a weight-loss diet, there are much, much simpler ones. For weight loss, I strongly advocate the use of fresh fruits and veggies, whole grains, lean meats and low fat dairy.
Pretty much, don't decide to go vegan to lose weight, then decide it's all too hard and give up on losing weight all together. If you've decided to lose weight, excellent!... but take baby steps.
Invest in good quality low-fat food choices. Sacrifice a small amount of flavour and extra money, and buy meat without the fat. (And preferably free-range)
Investigate portion control.
(How BIG should my serving size be?)
Exercise a bit more than you used to.
Identify the times and foods that are your weakness
and make a plan that lets you be strong
(ie. substitution or avoidance).
Learn about food and even aim for a few vegan meals a week... some are even listed on this blog to get you started.
This vegan blogger hasn't lost any weight since changing her diet - although there is a noticable change in fat and muscle distribution... that is, I now have more muscle and less fat!
There aren't too many vegan foods that are extremely high in fat content, but if you're worried that being a vegan will make you too skinny, then adding avocados, peanuts or unrefined oils to a dish is a great place to start.