Being a strict vegetarian, from a nutrition perspective, is a real challenge. Protein, calcium, vitamins D, C, B-12, zinc and folate are the nutrients to be especially alert about getting adequate amounts.
The alli diet is based on 30% total calories from fat, 20% protein and 50% carbs so you can use that formula to include fruits, vegetables, cereals, grains -- and protein foods like peanut butter, soy (and other) beans, tofu, and tempeh.
You might also want to consider a session or two with a registered dietitian who specializes in vegetarian diets. Then you can work together on a basic menu that will cover your nutritional needs, your vegetarian preferences, and the alli diet. To find a dietitian in your area (and by specialty) go to the American Dietetic Association: www.eatright.org
I hope this helps. Please let me know if you need anything else.
Pat Baird, MA, RD, registered dietitian