If you are looking for a quick fix Atkins isn't for you. Since you only have 20 pounds to loose total and you are already physically active the weight will not fall off quickly. Atkins is a lifestyle not a fad diet where you can come and let go of 20 pounds. We work very hard to loose the weight we do. Get a copy of the 2002 Dr Atkins Dew Diet Revolution (we call it DANDR here) - read it cover to cover so you understand what you are doing and follow the plan 100%.
Eat foods on the acceptable food list (sorry but there is no such thing as 0 carb foods), read labels of everything you eat so you know what the ingredients are and check with the hidden carb converter to find out how many carbs are REALLY in what you are eating.
Low Carb Diet Tools - Hidden-Carbs Calculator.
Atkins bars and shakes are NOT acceptable during induction – they are made with non-induction ingredients and cause stalling in many people. Just remember - if it’s not on the acceptable food list – it doesn’t go in your mouth. Drink a minimum of 64 ounces of water each day, including: Filtered water Mineral water Spring water Tap water nothing added --- WATER only!
After your 64 ounces daily you can have the following:
Clear broth/bouillon (not all brands; read the label)
Club soda
Cream, heavy or light (limit to two to three Tablespoons a day; note carb content)
Decaffeinated coffee or tea*
Diet soda made with sucralose (Splenda); be sure to count the carbs (may cause a stall in weight loss)
Essence-flavored seltzer (must say "no calories" and should not contain aspartame)
Herb tea (without barley or any fruit sugar added)
Lemon juice or lime juice (note that each contains 2.8 grams carbohydrate per ounce); limit to two to three Tablespoons
*Excessive caffeine may cause unstable blood sugar and should be avoided by those who suspect they are caffeine dependent. Everyone should try to avoid caffeine.
Grain beverages (coffee substitutes) are not allowed. Alcoholic beverages are also not permitted during Induction; those low in carbohydrates are an option, in moderation, in later phases
Good luck