Weight loss rate doesn't make sense

sofrances

I'm a bit confused by the rate at which I'm losing weight.

My food deficit isn't that high. At greatest it was 600 calories according to MFP when I was on 2000 calories. I have been slowly increasing, so now its 2300 and a deficit of 250 at my current weight.

However, my rate of weight loss is still pretty high, and does not appear to be slowing. In fact, over the past few days it has accelerated. I lost 2.3kg over the past week, and Libra suggests this means I'm on a deficit of more than 1800.

I'm doing a fair amount of exercise, but there's no way I'm burning 1800 calories through exercise. MFP estimates between 500 and 900 exercise calories most days.

I'm very confused by whats going on. I guess I should be glad, except that weight loss that is in any way "unexplained" is always said to be worrying medically, and it makes no sense that it would be accelerating after I increase my calories.

kimny72

The scale doesn't just measure the weight of your fat, it measures the weight of everything in there. Large weight swings up or down over a short period of time, like a week, is most likely water weight.

You measure fat loss by looking at the trend over multiple weeks and months.

If you're talking about more than a week or two...

How much time are you talking about and how much weight have you lost? What is your height and weight? What ever use are you doing and has it changed at all over this time period?

sofrances

My height is 1.87m. My weight is 101.2kg. My rate of loss since mid-May has been 1.8kg per week according to Libra, but 2.3kg in the last week. I have been trying to slow it down by gradually increasing calories, but not succeeding so far.

sofrances

In terms of water weight, I haven't been cutting carbs recently or anything like that. My macros are usually 18-25% protein, and then a more or less even split between carbs and fat, although I try to keep saturated fat under RDA.

AnnPT77

It's hard for me to piece together a clear picture of your week to week progress, so I'm not saying the following applies to you, I'm just throwing it out there:

Calorie needs estimates can be wrong, whether the estimate comes from MFP, a TDEE calculator or a fitness tracker. Those give accurate estimates for most people, but they're just putting out the average of the population that shares the same few characteristics (age, height, weight, self-assessed activity level, etc.). So, they'll be close for average people.

However, they'll be a bit off (high or low) for a few people, people who are further from average (in not necessarily obvious ways); and they'll be quite far off for a very rare few people. It's not at all common, but it can happen. That's just the nature of statistical estimates.

So, keep it in the back of your mind that those estimates aren't gospel, not a magical crystal ball. "The calculator's calorie estimate is wrong" isn't the first assumption someone should jump to quickly, and it should only be thought of as a possibility after weeks of experience makes it clear that it must be so.

Given enough reasonably accurate personal logging data - weeks of it - your actual average loss rate experience over multiple weeks is a better guide than MFP's or even a fitness tracker's estimate.

Even Libra can mislead, based on a week's worth of data. If you haven't changed anything in Advanced Settings, it's smoothing and projecting based on just 7 days of data, which sometimes paints a false trend. And that page with the kcal/day trend analysis is just goofy, if you ask me. I'm not going to delve into details, but they way they calculate those numbers is not the way I'd choose to do it, I think. I wouldn't take the one week figure there very seriously.

Is this calorie needs underestimate idea part of what's happening for you? Don't know. What I'd do in your case is continue to gradually take calories upward, based on your multi-week average loss experience, and see what happens. It's fairly unlikely, with small calorie adds, that you'll see a sudden big reversal.

Background for why I even put this out there: MFP and my (good brand/model) fitness tracker both think my maintenance calories are around 1500, more or less. For several months now, I've been losing at or close to half a pound a week at 1850, so my actual maintenance calories are around 2000-2100 (before exercise). MFP and the tracker are around 30% low: That's a lot. It's also consistent with my experience during 4+ years of logging, so I'm pretty sure it's right. It's rare, but it can happen.

Sometimes people think that what MFP - or a TDEE calculator or fitness tracker - gives them when set for maintenance is "their TDEE". Even igoring issues of TDEE vs. NEAT+exercise, it's not. It's "a statistical estimate based on limited data". The estimate provides the best practical starting point, but our true personal average TDEE (or NEAT) is something we have to confirm experientially.

sofrances

@AnnPT77 I certainly hope that its the app underestimating in my case - although I'm fairly content with the amount I'm eating at the moment, to be honest.

The only thing that has changed recently is that I have shifted most of my serious exercise to the morning. I don't know if that could make a difference though.

paperpudding

sofrances wrote: »

My height is 1.87m. My weight is 101.2kg. My rate of loss since mid-May has been 1.8kg per week according to Libra, but 2.3kg in the last week. I have been trying to slow it down by gradually increasing calories, but not succeeding so far.

Since mid May is only 1 month.

We will all have weeks of greater than usual weight loss and weeks of less. Weight loss is not linear - that's what that means.
I assume you are a man ( apologies if you are in fact a very tall woman) so 2000 to 2300 calories is not a large amount, is quite possible that you individually have a slightly higher requirement and eating another couple of hundred calories per day would get your pace back to, say 1/2 - 1 kg a week.

If you are continuing to lose weight WAY disproportionately to your calorie intake over a longer period of time, sure, see a doctor.

But not if it is only short term and/or a slight calorie increase amends the issue.

I guess the other question is how accurate your calorie logging is - we always ask that of 'I'm not losing as expected' threads as peoples estimates can mean they are eating more than they think.
Is possible in reverse too - ie if your logging is a lot of estimates, you could be under estimating and be eating less than you think.

AnnPT77

sofrances wrote: »

@AnnPT77 I certainly hope that its the app underestimating in my case - although I'm fairly content with the amount I'm eating at the moment, to be honest.

The only thing that has changed recently is that I have shifted most of my serious exercise to the morning. I don't know if that could make a difference though.

AFAIK, if shifting exercise to morning has an effect, it would be in how it affects your energy level during the exercise or for the balance of the day (possibly in subtle but still material ways, or possibly even noticeable to you).

For one, if you feel more energetic in the morning, you may unconsciously bring a little more intensity into your exercise, and burn a few extra calories via intensity. (Based on experience, I wouldn't necessarily expect heart rate to clearly reflect that difference, so I wouldn't expect a fitness tracker/HRM to register it. I know that I can do the same (power-metered) exercise, but get higher average-watts output at quite similar heart rates, and my tracker estimates similar calories, but the watt-based estimate differs more. It's not a huge difference, but it's a difference.).

Another true fact is that when I wake up, I'm like a slug in a fog for a few hours, not moving much, basically down-regulated. It's conceivable to me that if I exercise in the morning, the elevated heart rate and increased blood flow might lead to me being a little more energetic earlier in the day, or even through the day. On the flip side, exercise at night might interfere (again, perhaps only subtly) with my sleep, so leave me still yet more sluggish the next morning, to the detriment of daily life activity level and base physical processes, in ways that affect all-day calorie expenditure.

My exercise schedule has never been patterned enough for me to observe whether those speculations have any material effect for me or not, when it comes to unconscious calorie expenditure, or the accuracy of exercise calorie estimates, over a reasonable span of weeks. I'm not aware - perhaps someone else is - of well-conducted studies suggesting that exercise itself inherently has a different calorie expenditure - outside of intensity variations - based on time of day.

ETA: For clarity, if there are any effects along the above lines, I don't mean to be encouraging people to pursue them intentionally. I think that would be majoring in the minors, possibly an individualized thing even if true, and not big enough to deliberately focused on (probably there are other bigger fish to fry, for most people, to improve health, fitness, or weight loss).

cmriverside

It's also a fact that you've been at this long enough to be getting good at your calorie tracking.


I'm also one for whom MFP and every other calorie estimators is WAY off, and I eat a full 400-500 calories per day more than they tell me to eat for my stats.

So, to thine own self be true. Track as accurately as you feel you can and eat according to your long-term results.

And have a cookie if you want.

sofrances

paperpudding wrote: »

I guess the other question is how accurate your calorie logging is - we always ask that of 'I'm not losing as expected' threads as peoples estimates can mean they are eating more than they think.
Is possible in reverse too - ie if your logging is a lot of estimates, you could be under estimating and be eating less than you think.

I certainly try to be accurate. I use food scales rather than eye-balling, and for food that changes weight when cooking (e.g. rice, steamed veg) I weight both before and after cooking (at least, when the calories are given in uncooked weight).

sofrances

Thanks @AnnPT77, @cmriverside, @paperpudding, @kimny72 for your reassurances. I'll not panic yet, and I'll put the calories up 50-100 in a few days or a week if the trend continues.