Getting frustrated

panzafit

I am 4'11" and weigh (this morning) 157lbs. The past 3 months I have decided to eat healthier and started working out a lot more. I do 1 hour classes....Zumba, Kickboxing, Booty Camp, and Step Aerobics each week. On Mondays I will weigh about 157lbs. By Friday I usually weigh about 154lbs. Come Monday, I'm back up to 157lbs again. I don't seem to be losing inches either. My typical food on any given day is protein shake in morning, apples & Cheese for snack, Weight Watcher Smart one for lunch, 100 calorie almond pack for snack, chicken or steak for dinner with veggies and no evening snack. Oh and a glass of 2% milk before bed. I'm getting extremely frustrated. Anyone have any suggestions?