Hello guys! Sorry for the long delay between posts, but now I'm back and I'm here again to explain the IIFYM concept!
So IIFYM, what is it?
I'll tell you! IIFYM stands for, If It Fits Your Macros. It's a basic logic concept that you may, maintain, gain or even lose weight, by hitting your daily macronutrients requirements (Protein, fats, carbohydrates).
Let me explain abit more about it.
Say a 200lbs man at 20% bodyfat wants to lose weight. His maintenance calories is 3000, and to cut he would need to eat around 500 kcals under his maintenance, so ~2500 calories.
Now if he ensures that he get atleast 1.5g protein per lb/LBM (Lean body mass, so in a 200lb man with 20% bodyfat, subtract 20%, and that leaves you with 160lbs): 1.5*160=240g protein
Then he would need to get around 0.45-0.5g fat per lb/BW (Body weight): 200*0.45=90g fat
That would mean, he gets 1770 kcals from both fat and protein requirements (240*4 + 90*9 = 1770kcal)
Now he got 730 left in the day that he can fill up with whatever he wants, whether it be McDonalds, chocolate or salads, if he hit 2500kcals, he WILL lose weight!
To sum it up!
-200lb man at 20% body fat wants to lose weight
-Maintenance calories: 3000
-Calories to cut: 2500
-1.5g protein per lb/LBM: (1.5 * 160) 240g
-0.45-0.5g fat per lb/BW: (200 * 0.45) 90g
-Calories from fats + protein minimums: (240 * 4) + (90 * 9) = 1770
-Calories from reaching minimums taken from calories to cut: (2500 - 1770) 730
-He has 730 kcal left to fill with whatever foods he chooses and still lose weight as a result of remaining in a calorie deficit.
How to estimate your maintenance
Your Macronutrients needs
How to estimate bodyfat levels