The FastDay Forum

[Betsysgr8]

Why do we aim to eat our current TDEE on non-fast days, when clearly, this is NOT our goal TDEE? Wouldn’t it make more sense to look at both the TDEE for our goal weight and our current weight?

For instance, my current stats 5’5” 176 lbs female 50 yrs old. My goal is 135 lbs. Using Fitness frog http://www.fitnessfrog.com/calculators/ ... lator.html (just as an example) my current TDEE for no exercise (sedentary) is 1782 calories/day. TDEE for goal at no exercise (sedentary) is 1568 calories/day. So instead of learning what is right for maintaining my current weight, shouldn’t I be looking at what is right to maintain current minus 10 lbs and re-adjusting for each 10 lbs lost? TDEE for 166 lbs is 1720, TDEE for 156 lbs is 1677 and TDEE for 146 is 1625.

You are trying to create a caloric deficit over the course of the week, not each and every day. Actually, once you hit your target weight, if you continue to fast once or twice per week you'll want to eat about 130% of your TDEE on normal days if on 5:2 or 113% of your TDEE if on 6:1, assuming you are sticking to 25% of TDEE on your fast days. Any less and you'll continue to lose weight below your target.

Also, you may wish to ask yourself if you picture yourself as sedentary in the long term, after you've achieved your weight loss goals. I like the idea of "feed the person you want to become," because it will help you sustain the loss after you get there and there will be less of a transition that can often undo all the hard work you've put in to get there. That said, you should plan to succeed, and you don't want your body to get used to a general caloric restriction because that can lead to lower average metabolism at a given weight.

I mean, once you hit your target weight, you don't want to keep on losing until you hit a weight that is a stone (or more) lower than your target, right?

[Betsysgr8]

I was using sedentary in the example for similicity and because it has the lowest calories, since it appears that people are shocked by their TDEE's. I think what I was trying to get at is that we should look at what our goal TDEE is likely to be and that we should be actively seeking a day or 2 each week with consuming our goal TDEE. So maybe our week might look something like this: 2x500, 2xgoal TDEE, 2xcurrent TDEE and 1 do as you will day.

If you use the Katch McArdle equation for TDEE it may be the same at goal as currently, as it uses only lean mass.

With a continuous calorie restriction your actual TDEE may fall too, but probably not by more than 100 calories/day.

It's worth noting that the TDEE estimations are for people of a stable weight and don't necessarily apply to those in caloric deficit or actively losing weight.

If you have a way to go then extra calorie restriction might be appropriate but the basis of 5:2 is to generate the calorie deficit on the fast days.