Weight gain in a calorie deficit?

[misscopilot]

Hey guys!

I have lost 20 kg since January and my goal is to lose another 10-15 kg. My lowest weight was 78.4, then I went on vacation for 2 weeks and gained 5 kg which luckily all were water weight and were off again after a few days, leaving me at 78.7. I recently started a new job around a week and a half ago where I have to bike a lot. I usually have a calorie burn of 3300 kcal a day. I try not to let the deficit get too big of course so I mostly try not to let it get over 1000. Well what has happened? I gained weight and I keep gaining it every day. I'm now at 80.2. I dont understand this. I thought if you're in a calorie deficit you will always lose weight. I thought it was water weight at first but it has stayed for a week now, can water weight really stay that long? I havent had any breaks btw since I'm working pretty much every day. How can it be that I have a deficit of 1000 every day and that I actually gain weight? This is super demotivating. 

Any advice is appreciated.

[Heybales]

If you are in a calorie deficit you will lose fat weight.

But many reasons to gain water weight, especially when starting a new activity like biking more.

The calorie burn on that could also be inflated, by HR-based calorie burn even.

Give some stats on that - distance, time, calorie burn given.

Stress caused increased cortisol can cause slowly gaining upwards of 20 lbs in water weight.

Stress from new job, new routine, life, weight, lack of sleep, amount of deficit, ect.

And it'll stick around while remaining stressed.

Keep a fact in mind.

Fat is NOT fast, lost or gained.

3500 extra calories ABOVE maintenance is required to gain 1 lb of fat. Over whatever period of time you use.

Since you aren't even eating that much every day - is it even possible for it to be fat?

Now you've confirmed it cannot possibly be that - what could it be?

Let's pretend the calories from the biking are 100% inflated, double what they actually are.

What number have you been given, what is half that, and what would that make your daily burn?

And you are eating?

Again - could it possibly be fat weight?

Have you been able to keep accurate food logging with new job, logging all food by weight?

Are you eating out more?

[Glenda]

@misscopilot We have this wonderful little gadget that counts calories used no matter what we are doing.  I was thrilled to have something that shows that when I'm not on a machine that counts them, but that doesn't work.  Forget calories used and concentrate on how many calories you eat and don't eat more than 500 less than your maintanende number for your sex, height and weight.  Then you will lose weight.

[Rona1117]

Here is what worked for me after experiencing similar issues.
I needed to ignore the number of calories certain plans (and Fitbit) said I could consume and lose weight, and then come up three calorie numbers, or levels, on my own. 
Since my exercise is consistent week to week, I ignored calories burned. (I’d gain a ton of weight if I ate the daily calories remaining as stated in the Fitbit app. )
For several weeks I carefully counted calories and weighed myself often.  I was then able to arrive at the three numbers that worked for me: 

-I lost weight by consuming no more than 1800 calories. 
-I maintained weight at 2000 daily calories. 
-I gained weight at 2200 or more calories. 
Again, even though I’d finish a day with 2000, for example, Fitbit would say I could consume hundreds more due to calories burned. If I did, I’d gain a significant amount of weight over time. 
So, I can only suggest to take a few weeks of experimenting with calorie-counting and weighing daily during that time period. You should then be able to come up with the three numbers (lose weight, maintain weight, gain weight) that work for you and your level of activity—ignoring the calorie amounts outside programs say are right for you

[DoctorCoral]

I have been struggling with this myself as a large individual (120 kg) who exercises for 2-3 hours/day x 7 days/week (maybe 1-2 days off a month). I have always counted calories, but, until I got my Fitbit in July of 2020, I really had no idea how many calories I was burning. Well, it turns out that, at least since July, I consume 2200-2500 calories/day and burn 3500-4000 (running, swimming, or biking). My average deficit is about 1,000 calories/day then, and it is NEVER less than 700 (i.e., I always burn 700 more than I consume). If you multiple 1,000 calories/day x 3 months, that would be 90,000 net calories burned, which means I should have lost about 30 lbs (14 kg).....but I actually gained a few kgs. At first, I thought this was impossible: it's violating a law of thermodynamics! BUT then I saw this: https://medium.com/personal-growth/the-useless-concept-of-calories-50831730cc81. It's nothing new: if you eat 2500 calories' worth of lettuce, you will surely lose weight faster than were you to consume 2500 calories in sugar and lard. But even then, I feel like a 90,000-calorie deficit (it is actually 105,000, not that I'm counting 😉 ) should result in SOME weight loss. Maybe not the full 30 lbs this should technically equate to. I'm actually wondering if there are any physicians/nutritionists or researchers out there who might want to use me in their studies given this highly anomalous behavior: how a man who eats a healthy diet and burned 100,000 calories (net) over three months gained weight. Are my cells fundamentally changing their physiology, taking on excess water as a strange response to starvation? Maybe my body figured out a way to turn water into energy, and I am the solution to Earth's energy crisis.

[DoctorCoral]

As this is happening to me (see longer post below), I am wondering if it could be due to the fact that, as we exercise more, our bodies more efficiently use energy stores, meaning it becomes progressively HARDER to lose weight since you have become more efficient. So, our Fitbits might SAY we are burning 3500 calories/day (in my case), but in reality it's 2200. So, here I am thinking I'm at a net deficit of 1,300/day (burn 3500 normally and consume 2200), but, if my body is ACTUALLY burning 2200 (i.e., Fitbit is not accounting for my altered metabolic rate), then this could explain why we are not losing weight, despite huge caloric deficits. It seems like Fitbit really just considers pulse, sex, weight, and age, so I wonder if it's calorie burning estimate is just entirely wrong for some people (i.e. us). I'm hoping a nutritionist or physiologist may chime in and provide insight on this. Although I am a scientist, I work on marine invertebrates! In marine invertebrates, as it turns out, fit organisms use energy more efficiently and would lose weight at a caloric deficit, so if we were fish, we would be losing weight given our situations and behavior....

Oh! This might be useful, and I'd be curious if it is the same case with you: I consume ALL of my daily calories in a relatively narrow time window. 2-8 pm. So I am essentially fasting 18 hours/day. one would think that this could be good for weight loss, but maybe not??

[Heybales]

Intermittent Fasting, like any other diet, is merely a means to cause a calorie deficit that may be useful.

People have gained fat doing it, doing keto, doing low fat, doing vegan, doing plant based, ect.

There is nothing magical about IF or any other diet.

If you have problems with pre-diabetes it has shown to make some improvements to health markers. Not as much as just losing weight does in general, but some.

Read my post to your post in the other topic, might want to start your own topic though with answers to those questions.

oh, your daily activity is based on distance, if HR and steps goes high enough or you manually start a workout, it's based on HR.

Distance is more accurate if you are doing a distance based workout like running or walking.

Many reasons why HR-based can be thrown off.

But start your own topic with answers to my questions in other post - probably find out where your issue is.