Google calorie zig zag, its the same basic premise, but instead of zig zagging your daily calories you do it with your PP instead. One way to work it out is to total all your PP for the week including WP and set your self a certain limit per day therefore your body will never get used to a set amount of calories, which it would when working to a calorie controlled daily level. The body becomes more efficient as it starts to expect a certain amount of fuel based on what has happened previously in the last few days. It can only take a couple of days for your body to get used to this so different amounts keep it "shaken up" Read below for the more scientific explanation
e.g
(29PP x 7)+49 = 252 PP per week total
Day
1 = 35, 2 = 47, 3 = 29, 4 = 30, 5 = 38, 6 = 29, 7 = 44 total = 252PP
Taken from Calorie calculator site :-
"Over time our bodies adapt to the lowered calorie level. Our body becomes more efficient at using energy (lowered metabolism), and therefore burns less fat. This is why most of us reach a weight loss plateau. At this point,
the only option is to boost metabolism; increased cardio, weight training, 'cheat' meals (i.e. occasional high-calorie meals), cycling (or zig-zagging) calories, and even manipulating macro-nutrient ratios can all help to do this (don't forget adequate sleep and hydration). You often find that the nearer you get to your goal weight (or body fat percentage) - the harder things get!
Continually dropping calories only serves to lower metabolism even further - the moment you return to 'normal' eating - the weight comes back on." => i.e starvation mode where it stores as much as it can because it doesn't know when next the food supply will be plentiful.
Hope this helps