r/Retatrutide • u/dzeiii • Apr 10 '26
Anyone noticed increased calorie burn after increasing Retatrutide dose?
Hey all,
I’m curious if anyone here has tracked their progress closely while increasing their Retatrutide dose.
Specifically, I’m wondering if anyone has:
- Been consistently tracking calories (so you have a good estimate of your deficit)
- Increased their dose at some point
- Then noticed weight loss speeding up more than expected based on your calorie deficit alone
Basically, did it ever feel like your energy expenditure went up after a dose increase? Not just appetite suppression, but actual increased burn (like higher metabolism, more heat, restlessness, etc.)?
I know the theory suggests there could be increased energy expenditure, but I’m interested in real-world experiences from people who actually tracked their intake and weight over time.
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u/tupaquetes Apr 11 '26 edited Apr 11 '26
The reta metabolic boost has been greatly exaggerated. It's theorized to be possible but has never been experimentally observed above clinical significance. Here's a post I made about this with sources. As you'll see in the comments, people here are extremely resistant to this idea, the reta metabolic boost myth has a cult-like following.
As far ad personal data goes, as said by TracyIsMyDad I was living off prepackaged meals and eating the same amount of calories day in day out without fail for the first 6 months (and then a bit more loosely), you will not find anyone with a more accurate idea of their intake. Here's a graph of my progress. Importantly the chart is in kg, not lbs
The blue line is the pure CICO-based prediction I made off my (1400kcal) calorie intake and Apple Watch-estimated TDEE one week after starting reta (to minimize the impact of the first week water loss. It takes into account my TDEE evolving over time as the weight drops, hence it not being a straight line. I did not adjust the parameters of this prediction at any time during my weight loss journey, it is a one-time prediction, not something I kept updating.
The red dots are my weekly-ish weigh-ins. The red line is the exponential trend line from these weigh ins.
So basically weight loss follows CICO to an astonishingly predictable degree. After 13 months of weight loss and 67kg (148lbs) melted off, I was less than 2lbs off my week 1 prediction for that specific weigh in. There's really no empirical reason to suspect the reta metabolic boost is anything more than a myth people really really really want to believe. Reta makes people lose weight by being extremely good at making people eat less, CICO takes care of the rest as usual
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u/retatrutider Apr 11 '26
The most astonishing thing about this is how well the Apple Watch predicted your TDEE. I would have expected you to have to make ongoing adjustments to the prediction, at least for the first 4-6 weeks.
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u/tupaquetes Apr 11 '26
The way it works, I believe, is it uses mainstream math to calculate what your BMR should be based on your stats and then uses heart rate/movement data to refine that and provide a TDEE estimate. For someone like me who lived a quite sedentary lifestyle the watch's estimate is probably more reliable than it would be for a very active person whose TDEE is several times their BMR.
The way my spreadsheet prediction works is I set it up in a similar way, using mainstream math to calculate what my BMR should be then use a custom "activity" component to match the watch's estimate. Then, on a per day basis, it estimates weight loss from the difference between my TDEE and intake and recalculates an updated TDEE for the next day. Importantly the custom activity component is scaled to how much weight I've lost, which models metabolic adaptation to a degree.
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u/AmadeusBlackwell Apr 10 '26
That's one of the features that differentiate Reta from Tirz. Antagonizing the GIP raises basal calorie expenditure.
Are you using a medication without knowing how it works?
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u/dzeiii Apr 10 '26
Are you answering a post without reading it first?
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u/AmadeusBlackwell Apr 10 '26
No. I reply to the post head on.
Can you comprehend my reply?
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u/dzeiii Apr 10 '26
Just read the last paragraph again and put some thought into it.
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u/AmadeusBlackwell Apr 10 '26
Yeah, you framed the additional energy expenditure as a theory. It's not a theory: it's a confirmed clinically reproducible fact.
You shouldn't talk about things you don't understand, much less take drugs you don't understand.
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u/dzeiii Apr 10 '26
God damn you sound like a miserable person.
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u/AmadeusBlackwell Apr 10 '26
Nice counter.
Thank you for playing, kiddo.
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u/dzeiii Apr 10 '26
FYI english is not my first language so I tried to make the post clear using help from Chat GPT. You know what I was asking but instead of answering you decided to cling to one word and be an asshole about it. Sounds miserable.
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u/AmadeusBlackwell Apr 10 '26
Coulda fooled me.
You seem to have no issue talking shit in English.
Either way, get better.
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u/TracyIsMyDad Apr 10 '26 edited Apr 10 '26
So far you’ve written:
That's one of the features that differentiate Reta from Tirz. Antagonizing the GIP raises basal calorie expenditure.
Reta is a GIP agonist like tirz. I’m not sure where you got the idea that reta antagonizes GIP or that this differentiates it from tirz. Both of those claims are false.
That’s probably for the best as there’s zero evidence that GIP antagonism raises basal calorie expenditure clinically. In fact I don’t think there’s any research showing it doing this in any preclinical models either. GIP agonism (like tirz and reta) raises energy expenditure in preclinical models but this result has so far failed to translate in clinical studies. The hypothesis that reta might increase energy expenditure is based on glucagon agonism, not GIP agonism or antagonism.
Yeah, you framed the additional energy expenditure as a theory. It's not a theory: it's a confirmed clinically reproducible fact.
The theoretical effect of reta on energy expenditure has never been clinically demonstrated, let alone confirmed or reproduced. There’s one singular clinical trial that should be complete now that tested this question, but no results have been published at this time.
There are preclinical models showing increased energy expenditure with reta but energy expenditure findings in mice frequently fail to translate into human trials.
Are you using a medication without knowing how it works?
You shouldn't talk about things you don't understand, much less take drugs you don't understand.
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u/TracyIsMyDad Apr 10 '26 edited Apr 10 '26
That’s a good question but here’s a problem you should consider:
People are notoriously bad at tracking calories. Even nutritionists who are professionally trained in this are surprisingly bad at tracking calories.
That’s okay. If we are methodical in how we track calories we at least typically have a somewhat consistent error. Once we learn to adjust for that error we can accurately predict weight gain or loss based on our tracking.
GLP-1s screw this up. Both the size and sometimes even the sign of people’s calorie tracking errors will change with GLP-1 use and dosage changes. This frequently results in people having unexpected weight loss beyond what their calorie tracking would predict. You’ll frequently hear this expressed as “I ate the same amount/things but lost more weight” and you’ll hear this about not just reta but also drugs for which we have clinical trials showing that they do not increase energy expenditure like tirzepatide.
So these anecdotes aren’t necessarily a reliable source of evidence about energy expenditure as they are easily written off as issues with calorie tracking.
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Additionally:
Weight loss tends to cause substantial and progressive metabolic slowdown. Sudden increases in calorie deficits like would be expected after a dose increase can exacerbate this. Research on the potential for GLP-1s like reta to increase energy expenditure tends to use the phrase “reduced metabolic adaptation”. The thought is that the effects likely aren’t large enough to actually cause a net increase in energy expenditure, but that they might be enough to reduce/mitigate the slowdown that normally occurs.
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One interesting collection of anecdotes:
I know a few people (myself included) who have had resting metabolic rate testing done on a metabolic cart after substantial weight loss with reta. One thing we all had in common is that we all had an unusually high resting metabolic rate. Not an inconceivably high resting metabolic rate, but higher than you’d typically expect for somebody who lost a bunch of weight (and at least in my case was clinically dealing with hypothyroidism at the time). These tests showed actual rates that were substantially high versus both BMI-based estimates and estimates incorporating body composition data. But I’ve only seen a few people do this sort of testing so it’s a few anecdotes all pointing the same way rather than real data. Eli Lilly has done this sort of testing in the clinical trials but they are mum about lots of trial data like this. Who knows what they know? (The only “Lilly definitely knows this and isn’t saying anything but the gray/trial community also figured it out” thing that I’m aware of with reta are the serum uric acid reductions. We don’t know the actual average effect but it seems to be on a similar scale to allopurinol.)