Barb, when I first went vegan I just let myself eat whatever I wanted. My weight seemed normal even at it's highest, so I didn't even realize how heavy I was looking until a coworker who has no tact at all pointed it out. But I'm glad he did. I started out by exercising three times a week for half an hour on the elliptical, and eventually upped it until I was doing six times a week.
At the same time, I started tracking my caloric and vitamin/nutrient intake on www.fitday.com
. I also cut calories, so that I was only eating about 1,400-1,600 a day at first, and gradually ramped it up as my activity level increased. The increase in my activity level sped up my metabolism. I started focusing on packing as much nutrition as possible into the calories that I had, using fitday as my guide.
That took me down 15 pounds. Then, I started running. That took me down the next 15 pounds in a very short time, and also enabled me to eat WAY more food!
I don't track my calories any more except for on occasion. The running is what has made me lean. I currently run 40-50 km a week, and I do weights/crunches maybe three times a week.
I'm not a big woman in the first place, I was a small, slight woman who put on a lot of fat due to inactivity and too many calories. I'm not sure exactly how my stomach got so flat, I think part of it is I don't have a lot of body fat on me period due to exercise and diet, and another part is just how I'm built.
The cornerstone of my diet is a 16 ounce smoothie I consume every day that includes two servings of salad greens, soy milk, kale, fruit (strawberries, banana, pineapple, berries, etc.), fruit juice, VEGA, maca, and sometimes wheatgrass juice and chia/salba. I also eat kale, spinach or broccoli every day. I eat a full dinner, but I graze all day until that point which keeps my metabolism ramped up.
Hope that helps.