Could be muscle. Muscle weighs more than fat. Or it could just be water weight. 10 lbs in 4 weeks is a pretty steep increase, so water would be my first guess.
Unless you're morbidly obese, though, I'd ignore the scale. Worry more about your Body Fat Percentage and how you look in the mirror. Those are more accurate measures of your health.
QFT.
No scales, no BMI, no numbers, just look in the mirror.
I am obese, and medically speaking morbidly might be a proper designation.
I'm doing between 30 and 80 crunches per day, and then I usually get in four days a week, doing everything twice a week and then one day for just arms and one day for just legs.
As for what I'm eating, I usually have a yogurt or bagel and cheese for breakfast, a sandwich for lunch, and then a normal dinner. I try to have a spinach salad with dinner, and often will have it instead of a sandwich at lunch.
I'm not trying to get huge or ripped. I'm just lifting with the hopes of developing some better muscle tone and dropping some pounds. If I could shed enough that I could jog comfortably, I'd like to add that later.
Am I expecting too much too soon?