Have you used the Harris Benedict Equation to calculate your caloric needs? For women it's:
655 + (4.35 x weight in pounds) + (4.7 x height in inches) - 4.7 x (age in years).
Once you get that number multiply it by 1.55, since you are following the INSANITY program. Now, the number you have reached will be your caloric needs for weight maintenance. Subtract 500 from that number and ta-da, you've got your caloric needs for weight loss!
The nutrition guide says to increase your calorie intake once you reach month two, but everybody is different, so listen to what your body is telling you. If you want to loose weight faster, eating less calories will definitely help, but if you pass out during the workout, you might want to increase calorie intake… Also, as a loose guide, try to make your meals 40% protein, 40% carb, and 20% fat.
Also, it takes about 4 weeks to see your body changing, and if you are sore after your workouts your body is probably retaining more water than normal...
Hope that helped!
I think you call me … Sexy.