I recommend almond milk over soy milk. No need to punish yourself. Also, some people who go vegan don't lose weight because a lot of vegan foods (especially vegan foods that pretend to not be vegan foods) are kind of fatty. It also takes a lot of effort to stay healthy and make sure your body gets enough protein and vitamins. So, I'm not sure that it's necessarily a good choice for weight loss. Also, beware whey when buying your food, as it is a milk product that most people aren't aware is a milk product.
On that topic, I had oatmeal w/ almond milk this morning.