In my opinion Keto has the highest risk of losing muscle so I would not use Keto. I have read mixed reviews about intermittent fasting but have never tried it. Here is my opinion the best way of going about finding the right nutrition plan and the most important part is finding what works for you!! I found this online and it is very similar to what I do to start a estimated caloric need.
1) find your body fat. Bioelctricl impedence is the most inaccurate way of calculating your body fat. Dylan did a video on how to calculate your body fat percentages I suggest you watch that.
2. Take your body fat percentage and subtract it by your total body weight for your lean bodyweight. If you were 200lbs and had 15% body fat, then you would have a lean bodyweight of 170lbs. 200 x .15 (covert body fat percentage to decimal point) = 30. 200 - 30 = 170lbs
3. Convert your lean body weight from lbs to kg (if you weighed in kg, you can skip this) by dividing your lean body weight by 2.2. 170 / 2.2 = 77.27kg
4. Input your lean body weight into the formula 370 = (21.6 x 77.27kg)
5. Multiply 21.6 by your lean body weight 21.6 x 77.27 = 1669.032
6. Add 370 to that number to get your BMR 1669.032 + 370 = 2039.032, or 2039 calories
Having figured out your BMR, you now need to calculate your TDEE. This is done simply by multiplying your activity level in this list below with your BMR.
If you are sedentary (little or no exercise) : Calorie-Calculation = BMR x 1.2
If you are lightly active (light exercise/sports 1-3 days/week) : Calorie-Calculation = BMR x 1.375
If you are moderately active (moderate exercise/sports 3-5 days/week) : Calorie-Calculation = BMR x 1.55
If you are very active (hard exercise/sports 6-7 days a week) Calorie-Calculation = BMR x 1.725
If you are extra active (very hard exercise/sports & physical job or 2x training) : Calorie-Calculation = BMR x 1.9
Unless you have a very demanding manual labor focused job, it’s likely that you will use a 1.55 activity factor with the given workout split. Take your BMR 2039 and multiply it by 1.55 to get your TDEE
2039 x 1.55 = 3160
After finding your TDEE make you adjustments to that number for whatever goal you have.
Bulking= add 300-500 calories to your TDEE
Recomp= from a deficit of 250 calories- to your TDEE. This all depends on how you personally assimilate nutirients.
Cutting=a deficit of 500 calories
With all of these goals you must monitor you weight from week to week to make sure your heading in the right direction.
I set up macros a little different then using percentages. I start with protein and pending my goal decide how many grams I will consume in a day. I then go to carbs and start at 1 gram per lb of goal weight. I then go to fat and fill the remaining calories from fat. After I get my macros I test my numbers for 2 weeks and see how my body responds. If my weight stays the same after two weeks I know I have an accurate TDEE.