BMR vs TDEE for weight loss

BMR is what your body needs to survive. you don't want to go below your BMR. TDEE is Total Daily Energy Expenditure, how much your burn in a day (your BMR plus moving around).

You never cut calories from your BMR. That is your Basal Metabolic Rate and what your body needs to survive in a catatonic state while maintaining current lean tissues. Eating below your BMR can cause losses of lean tissue that would be undesirable.

TDEE is Total Daily Energy Expenditure which includes BMR + Normal Daily Activity (The combination of these two is often referred to as RMR or Resting Metabolic Rate) + the Termic Effect of Food (which some formulas account for in determining TDEE and RMR and others ignore because of the rounding down of the Atwater Factors used to determine calorie counts, IE: 4 calories per gram of carbs and protein and 9 calories per gram of fat) + Planned Exercise.

When we eat, we should consume close to the TDEE in order to maintain the status quo. I have my clients eat no less than 80% of their TDEE so that they don't get too close to the BMR and risk losing muscle instead of body fat.

Thanks, these responses are so helpful. So no cutting from my BMR, only cutting from TDEE. I'm calculating my BMR and TDEE using this online calculator:

http://iifym.com/tdee-calculator/

I know my body fat % and am using the Katch-McCardle equation since I am obese (I've assumed exercise level of 3 times a week to be on the safe side, even though I'm shooting for 4 or 5).

BMR: 1,591 calories
TDEE: 2,188 calories

So if I were to cut 20% from my TDEE, I'd eat 1,750 calories a day. That seems really high for a female, 5'8'', 230 lb. Perhaps the calculator is overestimating how many calories I burn from each exercise session? I tend to average 400 calories a meal, three times a day.

It really isn't depending on your activity level. What did you choose? At 5'5 and weighing less, I was cutting on around 1800 calories or more a day.

It really isn't depending on your activity level. What did you choose? At 5'5 and weighing less, I was cutting on around 1800 calories or more a day.

For activity level, I chose "exercise 3 times a week". When you were averaging 1,800 calories a day, what was your average weight loss? I want to lose 1 - 2kg (2.2 - 4.4 lb) a week, so I'm worried that eating 1,750 a day would let me lose maybe 1/2 kg at the most every week.

I was at about 1 lb a week, so .5kg. But keep in mind, I weighed less and required less calories overall. My deficit would be smaller than yours is even at the same number.

You have about 70lbs (35kgs) that you want to lose if my math is correct? If that is the case, 2kg a week is not a feasible goal at all. Your goal should be around 1.5 lbs a week, 2lbs at most (so 1kg per week at most).

-20% TDEE is about 1lb a week. You could bump it up a bit more if you wanted, to 25% but honestly, I would try it out for a couple of weeks (like more than 2 or 3) and see how it goes then adjust from there.