Calorie Deficit Question (Be Nice!)

How long have you been tracking your weight? How often do you weigh in? If you've only been doing it for a 4-8 weeks, say, then natural weight fluctuations could throw off your numbers a bit. For example, I weigh in every morning right after getting out of bed and going to the bathroom, before getting dressed and before eating breakfast. The conditions are as repeatable as I can get them, yet my weight can be up to 2-3 pounds different from one day to the next.

For example, I weighed in at 199.8 lbs today. I would not be surprised to see anything from 198.5-201.5 tomorrow.

And if you only weigh in weekly, those fluctuations could be pretty misleading. A 2lb fat loss could be covered up by an extra-low reading last week and a extra-high reading this week.

Just throwing that out there. The influence of this will of course diminish over time as you collect more data and expand your time window. In a 2-week window these fluctuations are a big deal; in a 3-month window, not so much.

Thank you so much everyone! Your replies and advice have been very helpful and I will take a more in depth look at the calorie deficits (or lack there of) without the 'active calories' factored in. I will look into giving the formulas a try as best I can too. It's nice to know there are actually nice people on these calorie tracking sites, most times I ask a question I just end up with 20 flame posts full of rhetoric and put downs.

Your Vivofit has to start the math somewhere on that daily burn estimate - all of them start with BMR.

And like the others, I'm betting it did NOT ask for your bodyfat % to get a better Katch BMR estimate, but the normal Mifflin or worse Harris BMR based on gender, age, weight, height.

If you have yo-yo dieted before, or even were doing a diet prior to MFP and Vivofit, you likely burned off decent amount of muscle mass. That does NOT follow the 3500 calories per lb, but when used for energy 600 calories.

So if you have less muscle mass than the device is aware of, all it's math for non-moving activities is going to be inflated.
I've seen differences between Katch and Mifflin be 200-400 daily, that's a sizable chunk, for perhaps 2/3 of your day, at least 1/3.

And if the stride length is off, it could be overestimating your moving calorie burn too.

So as others said, you only can confirm one side of the equation at this time with better accuracy - food.

Does Vivofit have a section that shows how many calories you burn per min during non-moving or sleeping time?
That figure x 1440 is the BMR they are using.

How does that compare to Katch BMR using BF%?
http://www.gymgoal.com/dtool_fat.html
http://www.gymgoal.com/dtool_bmr.html

Diet, me? No, yo-yo or otherwise. I have eaten healthy for years and used to walk to college and back daily. My gain was from pregnancy then severe inactivity from post-partum depression for almost two years, not overeating per se (though I guess my 'in vs out' was technically a surplus). However, I only have 19% skeletal muscle and roughly 56% body fat (according to my scale) when those should be 24.3% and 32.9% respectively so not great stats. I was never very strong, so the SM% isn't that surprising (I have trouble lifting milk gallons two handed). I do 5-6 minutes of 8-10 lbs weight lifting 2-3 times a week to help (my arms are shaking after that much).

Using the above links, my BMR is supposedly either 1445 (using my own bf% results from my scale) or 1630 (using the average from the calculator link).

My vivofit doesn't have a burn per minute amount, but it does have the "active calories are Total calories minus BMR", so using that formula backwards, it thinks my BMR is about 2252.


I'll take that inflation into account and see if I can find a balance that works based on the numbers I'm given.

So BIA scales can be very off too, though some can be consistent, and at least give a good direction. But at best, maybe 5% accuracy, just as good as those formula's.

So I'd actually use an avg of scale and avg of those measurements, which means BMR is down around 1500 likely.

I think Garmin must be doing something different with that formula, I can't believe their BMR would be that off, that's not close to any formula for your BMR or RMR based on your stats.
Might confirm your stats are correct on their site.

No graphs of calorie burn during the day, getting to see spikes and what not? I'm disappointed in them, they should have checked the competition to see what they should have copied.

So what you might do is take some weekly averages of total daily burn, divided by the BMR they appear to be using if stats are indeed correct.
So perhaps 3000 / 2250 = 1.33 for your personal activity factor. I would at least trust that part because if everything is inflated equally as bad, that math removes it.

Now apply that activity factor to better BMR estimate 1500 (or whatever it ends up being).
1500 x 1.33 = 2000 TDEE.

Now take deficit from that.

So whatever figure you arrive at for corrected TDEE, does that makes sense now with your results and eating level?

Also, if I can figure out how they arrive at BMR, I can help you adjust the height so they are using the 1500 or whatever instead of their figure - then you can start trusting it again and at least get what you paid for. Albeit by fooling them, but still.
I had to do it on my Fitbit. And last examined 39 days it was within 1% of results based TDEE.