My take on the P90X/Insanity/P90X2 Nutrition Plans
Obligatory disclaimer: I am not a nutritionist, personal trainer, doctor, etc. The following is a summary of what I've learned over several years of research and personal experience. I'm not a professional.
Now that that's out of the way...
Yes, you need to follow a nutrition plan to maximize your results. But you don't have to follow the nutrition plan included with your program to a T. They're guides, and overall they're great guides, but no nutrition plan can be one size fits all for everyone.
The recipes? They're great recipes, but there's no way I'd have the time to shop and prepare all of them. The portion plan? A nice start if you're new to tracking the types of foods you eat, but overall it's too simplified.
What many do instead of following the portion or recipe plans is 1) figure out your calorie goal, 2) figure out the proper macronutrient ratios for your nutritional phase, 3) track all food intake with an app like MyFitnessPal or LoseIt, and 4) pay attention to how it makes you feel and adjust when needed.
For step 1, I recommend going here to calculate your base metabolic rate. Take that number and go to this page to calculate how many calories you need to maintain your current weight. Then if you want to lose weight, subtract 500-1000 from this number. If you want to gain weight, add 500-1000. This is your daily calorie goal and it'll be way more accurate than the guide book is giving you.
Most of us can get this far without the nutrition guide. Step 2 is what will get you the results you want. In P90X and P90X2, they have you go through 3 nutritional phases: Fat Shredder, Energy Booster, and Endurance Maximizer IIRC. What they're really doing is giving you different ratios of protein:carbs:fats to hit. MyFitnessPal does a great job of tracking this for you. Here are the ratios you should aim for for each phase:
Fat Shredder: 50% protein, 25% carbs, 25% fat
Energy Booster: 30% protein, 40% carbs, 30% fat
Endurance Maximizer: 25% protein, 50% carbs, 25% fat
Now that you have some numbers to work towards, the food lists become really, really handy. Technically you can eat anything you want as long as you're hitting your calorie and macro goals, but your workouts (and in the long run, your overall health) will suffer. Keep in mind that food is fuel for your body. The higher quality fuel you put in, the better you'll be able to perform.
So Step 3. When tracking my food, especially in Fat Shredder, I found that I ate so many more carbs than I realized. Hitting my protein goal at first was really, really difficult. Protein powder, egg whites, and lean meats helped a ton. I also found that I typically ate far too few calories. It seemed counter intuitive to eat more to lose weight, but when I started fueling my body better, I had so much more energy to bring to my workouts.
And the most important, the part that no nutrition guide can determine for you, is step 4. You have to figure out what works best for your body. Personally, I can last for 2-3 weeks during Fat Shredder before my body starts protesting. I'll get headaches, I'll have no energy, and I'll generally be pretty cranky. When I see that happening, I know I need to increase the amount of carbs I'm getting. For some people, they can do Fat Shredder for much longer without having any trouble. Your mileage will vary.
I could go on and on forever about this, but I hope this helps somebody out there.
