So, I am on P1, week 3. I had my usual IP packet for breakfast around 8. I then walked 2 brisk miles at 11 and came back to the hotel for lunch, which was a packet with salad. Since I ate my usualky scheduled packet within a half hour of exercise, at lunchtime, do I still need to eat an extra packet today?

Thanks everyone!

I would - the extra packet has some to do with timing after a workout, but also about giving your body enough fuel to work with when you exercise. This diet is extremely calorie restrictive and you don't want to end up depleting yourself. I tried just a hard boiled egg after my walk and was definitely more tired by the end of the day than I should have been. So now I will be having a whole egg before I go and a RTD when I get home. See what works for your body and the level of intensity of your workout.