Yes I lost weight and I am vegetarian not vegan. I initially gained weight though because I was subbing lots of dairy for meat. Once I found a balance I really lost weight.
I eat cheese, and free range eggs and although I drink normal milk in tea (semi skimmed) I have soya on brekkie cereals. The tip for being a veggie is balancing it right. You can get all the necessary vits from a veggie diet and drink a bit of beer and still lose weight.
If you eat dairy weigh out your cheese grate it instead of slicing it - it goes a lot further.
I eat meat substitutes such as quorn and find it very good or I'll just eat the veggies you can cook them in all kinds of imaginative ways and still lose weight. Avoid frying or use a low fat spray.
Instead of snacking too I buy low fat natural yogurt and lots of fresh fruit and blend my own. Its lovely far nicer than shop bought sweets and yogurts.
Try having something like - toast for breakfast with a fruit smoothie - blend your own
or fruit yogurt drink
For lunch vegetarian pasta salads are nice - eaten hot or cold, You can premake them and take them to work they are very easy or if you make a batch of pasta for dinner make enough left overs for you to take it to lunch one day cold. Don't have too much dairy in your pasta though
Soups are another really easy option. Make a big batch and you can freeze it in portions and use them as you need them.
This website is excellent for low fat vegetarian recipe ideas
http://cgi.fatfree.com/cgi-bin/fatfree/recipes.cgi
For dinner I normally eat some sort of meat substitute, quorn, tofu etc. either with veggies, or in a stir fry or pasta or rice etc. its really versatile you can cook anything and its quicker to cook than meat.
I do walk and exercise too but I feel really healthy, I sleep well, I have energy and I only take a few supplements. i'd recommend taking something like echinacea which boosts general immunity and some mineral supplements I do take a calcium supplement but thats only because my dairy intake is quite low.
Hope thats some help.