TrendWeight Wackiness

SusanMFindlay

Anyone else find that TrendWeight's projection of how fast you're losing weight and how many calories you should add/cut to meet your goal is, well, wacky. My "loss in the last month" number is consistently between 3.1 and 3.3 pounds these days - so, pretty much 0.75 pounds/week.

But, every day, I get a totally different "calorie deficit report". It can be anything from "you need to cut 250 calories" to "you could add 100 calories". Anyone know what numbers they're using for that calculation? I would have thought it was the monthly loss number, but I don't think it can be given that that number is steady and this one fluctuates like crazy.

AnvilHead

Mine fluctuates wildly also. I'm not 100% positive, but to me it looks like they're basing it on the past week. For example, under "Statistics", mine currently says I'm losing 0.4 pounds a week, and under "Weight Change Over Time", my weight change "Since a week ago" is (coincidentally or not) 0.4 pounds. So it could be that the statistics are updated based upon a 7-day rolling basis - which would explain why it changes nearly every day.

SusanMFindlay

Mine has me with a 270 cal deficit (today) but 0.8 pounds lost in the last week, 1.3 the last two weeks and 3.3 the last month. I can't make any of those numbers work.

PAV8888

The weight change month / 2 week / week number is straight up comparison to trendweight value of a month / 2 week / week vs today.

The calories per day are based on either a 7 or 10 day average

I have told both trendweight and weighgrapher that I am aiming to maintain so they don't bug me with useless advice as to how much more I should cut to meet my goals.

I can figure out my own goals using my own spreadsheet of which trendweight is only one input point, and their projectiond have as much value as the MFP 5 week projection!

Remember that you can spot your trend from the trendweight graph as well or better than the trendweight app itself that has a built in delay of a couple of days when it comes to "sensing" changes

Maxematics

I do love Trendweight, but now that I'm lean I can't really trust it anymore for too much. I'm between 110 and 111 pounds, but when I'm ovulating I get a weight spike of 2 to 4 pounds for about a week. It goes down right before I menstruate and then I see a big drop after that's over. I also get crazy spikes after a day higher in sodium or if I go over my calories by a lot, which is my Friday night treat in which I order take out. Due to this, Trendweight tells me I'm losing a pound per week which turns into me gaining over half a pound per week in a matter of days, so I just ignore that part now.

SusanMFindlay

PAV8888 wrote: »

The weight change month / 2 week / week number is straight up comparison to trendweight value of a month / 2 week / week vs today.

The calories per day are based on either a 7 or 10 day average

I have told both trendweight and weighgrapher that I am aiming to maintain so they don't bug me with useless advice as to how much more I should cut to meet my goals.

I can figure out my own goals using my own spreadsheet of which trendweight is only one input point, and their projectiond have as much value as the MFP 5 week projection!

Remember that you can spot your trend from the trendweight graph as well or better than the trendweight app itself that has a built in delay of a couple of days when it comes to "sensing" changes

The recommendations fluctuate so much that I completely ignore them and just use TrendWeight for the graph. (I have my own spreadsheet for figuring out how/if I need to adjust calories.) I'm just a bit of a math geek, so I was curious if anyone knew what numbers they were using for math that doesn't seem to follow any rhyme or reason.

seska422

The Help section of the website says that they use "the methodology described by John Walker in his online book, The Hacker's Diet."

zyxst

I'd like to know what algorithm TW uses to figure out calories. I thought it used Fitbit numbers, but TW doesn't match Fitbit. Sometimes I'm burning calories, other times I'm overeating. I don't think it likes that I'm 8# under my goal weight.

seska422

zyxst wrote: »

I'd like to know what algorithm TW uses to figure out calories. I thought it used Fitbit numbers, but TW doesn't match Fitbit. Sometimes I'm burning calories, other times I'm overeating. I don't think it likes that I'm 8# under my goal weight.

I think that the only thing it pulls from Fitbit is your weight. TrendWeight then looks at your weight trend and your desired weight loss rate and compares the two to give a calorie adjustment recommendation to wrench your trend back to your desired rate.

SusanMFindlay

seska422 wrote: »

zyxst wrote: »

I'd like to know what algorithm TW uses to figure out calories. I thought it used Fitbit numbers, but TW doesn't match Fitbit. Sometimes I'm burning calories, other times I'm overeating. I don't think it likes that I'm 8# under my goal weight.

I think that the only thing it pulls from Fitbit is your weight. TrendWeight then looks at your weight trend and your desired weight loss rate and compares the two to give a calorie adjustment recommendation to wrench your trend back to your desired rate.

In theory - but my question originated because it *doesn't*. The recommendations can vary dramatically from day to day and almost never correlate to my trending rate.

PAV8888

SusanMFindlay wrote: »

seska422 wrote: »

zyxst wrote: »

I'd like to know what algorithm TW uses to figure out calories. I thought it used Fitbit numbers, but TW doesn't match Fitbit. Sometimes I'm burning calories, other times I'm overeating. I don't think it likes that I'm 8# under my goal weight.

I think that the only thing it pulls from Fitbit is your weight. TrendWeight then looks at your weight trend and your desired weight loss rate and compares the two to give a calorie adjustment recommendation to wrench your trend back to your desired rate.

In theory - but my question originated because it *doesn't*. The recommendations can vary dramatically from day to day and almost never correlate to my trending rate.

And that, my friend, is why I neatly sidestep the issue by telling the stupid thing that I am maintaining and paying as much attention to its projections as I am paying to MFPs!

@Maxematics weightgrapher.com allows you to superimpose a graph of a user selectable previous time period (default is 28 days). That way you might be able to visually compare your weight at the same relative times in your previous cycle. I also suggest with weightgrapher that you state that your goal is to maintain.

The value of all these tools, for me, is to make us aware that our weight level is not well represented by a single day's measurement, but by a cloud of repeat measurements.

Our own interpretation still has to come into play... or else we just have to give the tool a few days to catch up.

I ought to know by now whether my spike was mostly from sodium, or because I hit 3500 Cal over maintenance at the all you can eat buffet.

In either case Trendweight will still only show +0.1 or +0.2lbs for the one day. And will go back down in a couple of days from now when my weight reduces if it was sodium, or will stay up if it was 3500 extra Cal

seska422

SusanMFindlay wrote: »

seska422 wrote: »

zyxst wrote: »

I'd like to know what algorithm TW uses to figure out calories. I thought it used Fitbit numbers, but TW doesn't match Fitbit. Sometimes I'm burning calories, other times I'm overeating. I don't think it likes that I'm 8# under my goal weight.

I think that the only thing it pulls from Fitbit is your weight. TrendWeight then looks at your weight trend and your desired weight loss rate and compares the two to give a calorie adjustment recommendation to wrench your trend back to your desired rate.

In theory - but my question originated because it *doesn't*. The recommendations can vary dramatically from day to day and almost never correlate to my trending rate.

I haven't read The Hacker's Diet to see what gymnastics they are doing with the math but that's probably why the predictions aren't as straightforward as they seem they should be.