First off, I will say that I am NOT a certified anything as far as nutrition goes. I pulled all this information off the internet from what I consider reputable sites and have been putting it into practice for a couple years. I know this looks a little overwhelming, but just take it step by step and we can get this! First I will outline how to calculate your numbers by hand and then I will post a link to an online calculator.
If you want super specific numbers, we need to do this by hand, so break out your calculator! First, calculate your BMR (Basal Metabolic Rate). This is the amount of calories you burn by just being alive each day.
Calculate with w = weight in kg*, and h = height in cm*, and a = age
Women: (9.56 x w) + (1.85 x h) – (4.68 x a) + 655.
Men: (13.75 x w) + (5 x h) – (6.76 x a) + 66
*To figure out your weight in kg you take your current weight and divide it by 2.2
*1 inch = 2.54 cm
Pick a number from the list below that best describes your activity level on most days and multiply that number with your answer from step 1. This is how many calories you need each day to maintain your current weight/mass.
Activity Factor Category Definition
1.2 =Sedentary: Little or no exercise and desk job
1.375 =Lightly Active: Light exercise or sports 1-3 days a week
1.55 =Moderately Active: Moderate exercise or sports 3-5 days a week
1.725 =Very Active: Hard exercise or sports 6-7 days a week4
1.9 =Extremely Active: Hard daily exercise or sports and physical job
To achieve moderate weight loss, multiply your total calories from step 2 by 0.9 to see how many calories a day you should be eating. For more aggressive weight loss, (which I don’t usually recommend) multiply your calories by 0.85.
Once you have the total calories you will be eating each day, you will then figure out a macro split for yourself, this will be trial and error and you will need to try certain splits for 2 weeks at a time to figure out what works best for you and your body type. One of the most popular macro splits for lean muscle gain is 40/40/20 (40% carbs, 40% protein, and 20% fat) so I would suggest starting here. You would simply figure out these numbers by taking your calories for the day – we’ll use 1600 calories for an example:
Ex: 1600 calories a day x 40% (.40) = 640 calories. Carbs and Protein both have 4g per calorie so you would take that number and divide it by 4. 640/4 = 160. So you would eat 160g of carbs and 160g of proteins for the day. For Fats you will take your calories for the day of 1600 (example from above) and multiply it by .20 (20%) this will come out to 320. Fats have 9g per calorie so you take 320 and divide it by 9= 35.55g of fat per day.
Like I said, these numbers are just examples. Everyone will be different and your macros will be different depending on what your goals are. For example, as a generalization, someone who is trying to lose weight will have less carbs and more protein and fat, while someone who is trying to gain muscle will have more carbs and less fats and moderate proteins. If you really aren’t sure what macro splits to use, I suggest using an online macro calculator like this one: http://iifym.com/iifym-calculator/. This is a good site to educate yourself on the concept.