Congratulations on your weight loss. Walking is an excellent exercise.
I can’t explain why you have been able to eat anything without a detailed record of what you have been eating. To gain or lose weight, you must increase or decrease your food intake by 3500 calories over a week’s time.
One theory about body weight is called the set point theory. The setpoint is the body’s preferred weight that it tends to return to after any change in weight. The theory follows that if a person loses weight slowly, the body is able to readjust to the lower weight and reset your weight thermostat, much in the same way you lower your heat thermostat.
Rather than trying to see what you can get away with eating, I would suggest that you follow a weight maintenance plan of a few calories more than you ate to lose weight. Hopefully, you are including a variety of foods from My Plate: 2 to 3 servings milk; 2 to 3 servings meat; 6 to 11 servings bread; 2 to 4 servings fruits; 3 to 5 servings vegetables; use fats, oils, and sweets sparingly. You should also eat at least 1200 calories with a variety of foods to be able to meet your Recommended Dietary Allowance (RDA) of nutrients.