When I closed out my meal for the day is said in 5 weeks I will weigh 20 lbs more than I do now.

rachaelcraft wrote: »

The in 5 weeks said I'll be weighing 20 pounds more.

We have to put up with a little rain, if we want the sunshine.

klimptt wrote: »

I'd like to know the answer to your question. I'd like to know how that figure is calculated. The two answers above appear to be jokes.

My answer was not a joke.

MFP is:
* taking the daily calorie need it estimated for you,
* comparing that to what food and exercise calories you logged just for that one day,
* assuming that both its calorie need estimate and your logging are exactly accurate,
* assuming that every day for the next 5 weeks will be exactly the same, and
* calculating body weight results if all of those things were true.

That's if there's no coding bug or technical glitch in the picture.

All of those things won't be true. They can't all be true. It's impossible. That was the actual, serious point of my PP.

If the estimates and logging are all accurate or close (a big "if"), and your daily life is very consistent on average over the 5 weeks (another big "if"), then your weight in 5 weeks might be close to the prediction.

At most, interpret it as telling you you're on the right track that one day, or not. The numbers coming out exact in 5 weeks? Less likely.

For sure, don't let one day's weird result mess with your head.

It's never been right for me, through a year of weight loss (obese to healthy weight) and 7 years maintaining a healthy weight since. Clearly, I did fine despite that prediction being off.

It's not worth stressing over.

klimptt wrote: »

Ok Ann, I understand all that. My question is what formula is used to determine what the weight will be 5 weeks in the future. It takes your current weight, it looks at the calories used for that day, and then it determines if you took in more or less than you needed. My question is what table are they using to determine how many calories a given person needs. Is it basing it on age? Whether someone is sedentary? I thought when I joined there was a place to answer questions like that but I can't find it anymore.

Also why use 5 weeks?

https://support.myfitnesspal.com/hc/en-us/articles/360032625391-How-does-MyFitnessPal-calculate-my-initial-goals

That's the documentation.

All it's spitting out is basically a statistical average value, based on scientific research, for people who are similar with respect to the data items they say they use for the estimate. Most people are close to average, a few will be noticeably off (high or low), and a few will be surprisingly far off (still could be in either direction). That's the nature of statistical estimates.

If you know some stats, what I'm saying is that BMR (basal metabolic rate), which is the basis for the estimates, seems to have a normal distribution (can be graphed as a bell curve). More specifically, it has a relatively small standard deviation, i.e., it's a tall, narrow bell curve. Most people are close to the average value, but some will be outliers. (MFP's estimate is 25-30% low, for me. That's why I've looked into this somewhat.)

I have no idea why it's 5 weeks. You'd need to ask someone who works for MFP, and even they might not know anymore, i.e., I'll bet the decision goes way back.

If I had to guess, and it's purely guesswork, I'd consider one of two lines of reasoning as possibilities:

* It's long enough to encompass one full menstrual cycle for most adult but premenopausal women. Since water weight is weird from women's hormonal cycles, that might be long enough to see a pattern.

* People often say "stick to a new routine for 4-6 weeks". 5 weeks is in the middle of that. It's long enough to establish a trend. But one day (what they're using for the estimate) is not a trend.

Clearly, neither of those things applies to just one day, but if what they're trying to influence people to do is stick to a sensible path, a consistent series of day ought to lead to something in the vicinity of that weight, for someone who's statistically average, or close. Clearly, they're not going to use a short time period, because anyone who's successfully lost weight knows that "losing a pound a week" tends not to be a pound every single week. It's peaks and valleys, because of water weight, mostly.

I worry that the "in 5 weeks" encourages people to lose weight faster (often not smart), or to feel cheated or guilty if they don't lose as predicted.

I don't work for MFP. I'm just a regular MFP user like you, posting here in an effort to help new folks learn how to use MFP successfully, because success from MFP has been such a huge quality of life improvement for me. I'd like to see other people get there, want to help if I can. I don't do that perfectly, obviously. My advice is worth every penny you've paid me for it. Caveat emptor.

I still say ignoring the "If every day were like today, in 5 weeks . . . " is the best course of action. So do quite a few other old-timers on MFP, IME. Probably not all, though.