Use 600 calories a day or the TDEE calculator?

This topic contains 6 replies, has 4 voices, and was last updated by franfit 10 years, 6 months ago.

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Potlatch

1:44 pm
3 Jun 14
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I used this TDEE calculator to see how many calories I should eat a day when fasting: http://thefitgirls.com/tdee-calculator.aspx

The result was 675 so I have been using that.

But recently I read about the worlds biggest study regarding 5-2 (it is in swedish: http://www.svt.se/nyheter/vetenskap/5-2-fungerar) and in that study all men ate 600 calories a day.

So my questions are:

1) Should all men eat 600 calories or is it better to use a more personal value like the one I got from the TDEE calculator?

2) How come they did not use a more personal value in this study?

Metchick

1:56 pm
3 Jun 14
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Hi Potlatch

I’m guessing that it was easier to assume an average calorie requirement for men and women and to use that to calculate the calories for a fast day (1/4 of normal) hence 500 for women (2000 cals average) and 600 for men (2500 cals). It then makes it much easier to produce menu plans for those values. If each person worked out their own fast day calorie requirement based on their own TDEE, they’d have to do their own calorie counting and I, for one, would lose interest very quickly!

Potlatch

9:12 am
4 Jun 14
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Ahhh, that sounds logical. Thanks for the input (I was afraid that I was eating too much calories so I had to ask)

Metchick

9:42 am
4 Jun 14
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Have you seen Michael Mosley’s website: http://www.thefastdiet.co.uk ?

Potlatch

8:39 am
6 Jun 14
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I had not been there no. The TDEE calculator there gives a different result than the one I linked to. Which one should you trust? 🙁

Natalia

11:51 am
6 Jun 14
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Would that mean that with TDEE of 1676 calories my fasting calorie intake should be 400 only. mmm, it is going to be tougher than I thought.

franfit

12:37 pm
6 Jun 14
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It is absolutely fine to use the guideline of 500 calories per day for women and 600 for men. There is no special metabolic magic that happens at exactly 25% of TDEE, much to my disappointment 😉 5:2 causes weight loss by cutting caloric intake. The reductions in blood glucose and insulin that you get from fasting help with that. I started 5:2 last August at 157 pounds and 40 weeks later weighed 40 pounds less by eating 500 calories on fast days, being careful of what I ate on non-fasting days to keep my estimated calories under my TDEE, and gradually increasing my walking to an average of 10,000 steps per day. There is no need to go under 500 calories on fast days. Unless maybe you are an unfortunate person who is doing everything right and still not losing weight.