The FastDay Forum

I have been at dieting (for want of a better word) for 5 weeks now.
My 3 aides are 5:2 and TDEE, myfitnesspal and garmin activity tracker.

Observations:

5:2 TDEE is much higher than myfitnesspal, 2905 Cal vs 1844 Cal.

Garmin Cal burned is much higher than myfitnesspal, eg. my bike ride Sat morning was 58km, according to Garmin that burned 5065 Cal but according to myfitnesspal it was 3046 Cal burned.

If I combine the Garmin Cal burned with the 5:2 TDEE and the left over Cal weekly from MFP then in the 5 weeks based on 8800 Cal per kg I should have lost more than 10 kg already.

If I use only the myfitnesspal data i.e. daily allowed and their exercise burned calc I should have lost 3.97kg.

In reality I am 4.5 kg down in the 5 weeks.

I believe that I subconsciously skip the odd thing when logging on MFP and I am sure I pick the lesser of 2 evils when comparing 2 slices of pizza or KFC Aus vs NZ because there is no South Africa option. I also think MFP knows this and as such lowers their daily allowance accordingly.

If I logged on MFP but used the 5:2 TDEE I believe my weight loss would be much less than it is, similarly if I used the Garmin Cal burned as justification to eat more.

My point I suppose is that it is really easy to exceed a TDEE and genuinely wonder what went wrong and why the weight loss is less than expected.

Sorry for the rambling, I just find this extremely interesting and in time I am sure my thoughts will become more structured.

Well done on being so organised with the numbers! I tried doing that but failed.

I tried to count calories with MFP for a month or so and instead of losing weight I was gaining (very little and very slowly, but still). And I didn't cheat, I promise. After that month I thought "sod it, I'll go by my gut". And so far it's served me well

Well done on being so organised with the numbers! I tried doing that but failed.

I tried to count calories with MFP for a month or so and instead of losing weight I was gaining (very little and very slowly, but still). And I didn't cheat, I promise. After that month I thought "sod it, I'll go by my gut". And so far it's served me well

That is kinda what I am trying to say, it is so easy to leave something out or underestimate it and then use that as a basis to splurge a bit (becuase there is TDEE left over) and before you know it your efforts are for nothing.

When you log onto Myfitness pal the figures you are given are based on what calories you need to eat EVERY DAY to ensure you reach your target. The 5:2 is based on eating what would be a maintenance level diet for 5 days a week and dieting for only two. So the 5:2 figures are correct for fasting regimes. Basing your TDEE on the daily allowance others give you will mean you will be under with your TDEE on the 5 days and then you throw in super low 500kcal days as well, which may not be a bad thing as long as its sustainable for you..

Both of those numbers for a 58km bike ride seem high to me. That's about 36 miles, and this link shows a 10-16mph bike ride at a METS of 6 to 10, so picking 12mph and 3 hours you get a METS of about 8 or so and I'll use my weight of ~84kg to get to 84 x 8 x 3 = 2016kcal. That's a gross number, and since you could have been sleeping subtract 1 from your METS number to get the net calories burned by cycling and you get 84 x 7 x 3 = 1764kcal.

Unless your Garmin was tracking something else, like very steep hills (elevation changes) or a screaming high heart rate for the entire ride I'm thinking there's an overestimation there.

Both of those numbers for a 58km bike ride seem high to me. That's about 36 miles, and this link shows a 10-16mph bike ride at a METS of 6 to 10, so picking 12mph and 3 hours you get a METS of about 8 or so and I'll use my weight of ~84kg to get to 84 x 8 x 3 = 2016kcal. That's a gross number, and since you could have been sleeping subtract 1 from your METS number to get the net calories burned by cycling and you get 84 x 7 x 3 = 1764kcal.

Unless your Garmin was tracking something else, like very steep hills (elevation changes) or a screaming high heart rate for the entire ride I'm thinking there's an overestimation there.

Thanks, that is really interesting, so much to learn.

Hi there Brian1 Like you I too have perused several sites to discover my TDEE/Calories burned/Nutrition values average portion size etc. Everything a minefield for a technophobic like me. I only work 23 hours Mon-Thurs and not overly enthusiastic with exercise.
As this site often mentions 5:2 4:3 ADF Exercise/Physical activity is personal choice as we are all have very individual needs and expectations. This site so far has proved to me there is choice to mix things up a bit and still achieve a steady loss.
This month I 5:2 week 1 and lost a kilo which climbed back up by almost the same amount.We then had a family meal at a local harvester resturant(I could have had lower cal healthier choices but blew my TDEE right out of the water and then some!) However,as I recorded my daily calories consumed I have consumed 9957kcals over the 10 days (my current TDEE according to this site is 1656) Whilst I regained the kilo from my initial 7 day 65kg - 64kg - today 65.8kg I am not too disheartened as I know it will come back off and as long as I am less than 65 kg on 28th Feb however small a loss is a loss is an acheivement. I am the lowest I have ever been in 20+years and down to a UK 10. Even after last night blow out So my suggestion would be to stick to this sites calculated TDEE your fitnesspal for other needs and this site for the support gained from others and their achievements