Cindy if all that is in your non-fat capuccino is espresso and skim milk, yes, you can. Just keep in mind what Dr. A wrote about caffeine, and limit yourself to 2 servings a day. You can also add Sugar Free syrups to your capuccino (or latte or whatever) during Phase 1.
here is the info from the website-it looks like it does have some sugar in it, which i guess is a no no? What do you think?
Serving Size 12 fl.oz.
Cappuccino Espresso, steamed milk and foamed milk
Rich, full-bodied Starbucks® espresso in a small amount of steamed milk, with a deep layer of foam. With less milk than a latte, the classic and complex cappuccino offers a stronger espresso flavor and luxurious texture.
Amt Per Serving
Calories 80
Fat Calories 0
Total Fat (g) 0
Saturated Fat (g) 0
Cholesterol (mg) <5
Sodium (mg) 100
Total Carbohydrates (g) 11
Fiber (g) 0
Sugars (g) 9
Protein (g) 7
Vitamin A 8%
Vitamin C 0%
Calcium 20%
Iron 0%
* The nutrition information for beverages is based on Starbucks® beverage recipes. Because beverages are handcrafted, exact information may vary. Data is calculated using esha Research’s Genesis® R&D software, and rounded to meet FDA regulations. Data for vitamins and minerals refers to percentage of US recommended daily intake values.
Just keep in mind what Dr. A wrote about caffeine, and limit yourself to 2 servings a day. You can also add Sugar Free syrups to your capuccino (or latte or whatever) during Phase 1. 
