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Weight loss injections/treatments

Discuss weight-loss injections and treatments, including personal experiences. Mumsnet hasn't checked the qualifications of anyone posting here. You may wish to speak to a medical professional before starting any treatments.

Only way I can lose on Mounjaro is to eat no more than 500 cal and exercise

88 replies

PositiveEnergyyy · 28/06/2026 12:42

Hello everyone
I have been on MJ for 2 1/2 months. I have very good loss in the first five weeks I lost about 1 stone. I carried on the second month and lost 4kg. Then everything came to a halt. 4 weeks of losing nothing.
I upped my dose to 3 mg and still had great appetite suppression. I have always eaten about 900 cal a day forcing myself. I dropped my calories to 800 and then 700 still lost nothing. The only way the scale started to move a little bit is by dropping my calories to 500-600. I am still doing 10,000 steps a day.
I still have about 3 stones to lose to get to healthy weight and I can’t carry on eating so little. Even though I am not hungry, It is not healthy.
I take v low thyroid meds dose but my TSH is fine now and T4 which is low is within rage so no way the doctor will up my dose. I don’t think I have a whoosh effect coming either. I also took 2 days re feed and ate at 1100-1200 cal a day and that did nothing.
Everyone here says to up the dose when the appetite suppression goes but I have good appetite suppression. No sure what to do.
Grateful to anyone for suggestions that works or anyone with similar experience and what they did to get losing again.

OP posts:
S210873 · 28/06/2026 20:16

oliviaAustin · 28/06/2026 20:12

Nonsense. Nobody’s metabolic rate slows so much that they lose weight only on 500calories. Something else is wrong.

Maybe there, and she is going to speak to a Dr too, but look up metabolic adaptation, That's science, not nonsense.

Coldwetlettuce · 28/06/2026 20:19

It’s not possible to not lose weight if you’re consistently only eating 700 cals a day, even without exercise. You must either be underestimating how much you’re eating or have a medical problem. If you’re really eating that little every single day and not losing weight you need to go to your doctor to find out why

oliviaAustin · 28/06/2026 20:32

S210873 · 28/06/2026 20:16

Maybe there, and she is going to speak to a Dr too, but look up metabolic adaptation, That's science, not nonsense.

Metabolic adaptation only reduces caloric need by about 120 calories a day on average. If a woman’s TDEE is around 1700 that would mean they would still lose weight on 1400 even with metabolic adaptation. Otherwise how do you think anyone starves to death?

Adult women burn more than 1000 calories just by being alive even if they are small and slender.

Safarisagoody · 28/06/2026 22:02

How’s your body fueling itself then, if it’s not food or drinks and you’re not burning food or muscle, thus making your body lighter?

you need to speak to a doctor.

Safarisagoody · 28/06/2026 22:03

oliviaAustin · 28/06/2026 20:32

Metabolic adaptation only reduces caloric need by about 120 calories a day on average. If a woman’s TDEE is around 1700 that would mean they would still lose weight on 1400 even with metabolic adaptation. Otherwise how do you think anyone starves to death?

Adult women burn more than 1000 calories just by being alive even if they are small and slender.

Edited

Absoltely and you still lose weight as expected. I wonder if these posters have never seen an anorexic or a famine victim,

S210873 · 28/06/2026 22:41

Safarisagoody · 28/06/2026 22:03

Absoltely and you still lose weight as expected. I wonder if these posters have never seen an anorexic or a famine victim,

I wonder if you have spoken to a medic or a scientist and fully understand. The poor lady is struggling with her weight loss and continues to reduce her eating. If she was losing weight on 1000 or 1200, why do you think she went down to 500-600? Possibly a medical issue, as suggested. You carry on thinking you know better than the medical experts Rosenbaum & Leibel (2010), Adaptive thermogenesis in humans: https://doi.org/10.1038/ijo.2010.184
Müller, Enderle & Bosy-Westphal (2016), Changes in Energy Expenditure with Weight Gain and Weight Loss: https://doi.org/10.1007/s13679-016-0237-4
Heymsfield et al. (2014), Weight loss composition is one-fourth fat-free mass: https://doi.org/10.1111/obr.12143
van Baak & Mariman (2023), Physiological factors affecting weight regain: https://doi.org/10.1038/s41574-023-00887-4.

The Heymsfield et al. (2014) one is the strongest, should you care to read any of them, but sorry, of course you know better.

GreenLemonade · 29/06/2026 03:07

There is no way OP’s metabolism slowed down so much within 2 months that she can maintain her weight at 500 calories per day. Adaptive thermogenesis is real but this is way too extreme.

I see three possible explanations:

  • OP is eating more calories than she thinks
  • OP’s body is retaining water, possibly due to the recent heatwave, menstrual cycle or a combination of both, while weight loss is happening in the background
  • There is another medical issue

It could be a combination of all of the above. Solidarity, it must be disheartening.

RoseField1 · 29/06/2026 03:27

oliviaAustin · 28/06/2026 20:12

Nonsense. Nobody’s metabolic rate slows so much that they lose weight only on 500calories. Something else is wrong.

She's only been doing this for a short time because she mistakenly thinks she's stopped losing weight after losing 2 stone in 3 months 🙄

Tickingcrocodile · 29/06/2026 03:37

Eating 500 calories a day is extremely dangerous. My daughter is recovering from an eating disorder and we were told that if patients were eating 500 calories a day or less, this was the point they were immediately hospitalised. You could be doing serious damage to your heart and other bodily functions.

henlake7 · 29/06/2026 09:20

Also trying 'different strategies over 4-5 weeks' isnt a great idea. It wont be enough time to see a difference and will just mess your system up.
Maybe its time to step back and give your body a break.
Try resetting your calorie deficit to no more then 100 calories and give it at least 4 weeks.
Remember you arent in a race and there is no rush to lose the weight.

oliviaAustin · 29/06/2026 09:35

S210873 · 28/06/2026 22:41

I wonder if you have spoken to a medic or a scientist and fully understand. The poor lady is struggling with her weight loss and continues to reduce her eating. If she was losing weight on 1000 or 1200, why do you think she went down to 500-600? Possibly a medical issue, as suggested. You carry on thinking you know better than the medical experts Rosenbaum & Leibel (2010), Adaptive thermogenesis in humans: https://doi.org/10.1038/ijo.2010.184
Müller, Enderle & Bosy-Westphal (2016), Changes in Energy Expenditure with Weight Gain and Weight Loss: https://doi.org/10.1007/s13679-016-0237-4
Heymsfield et al. (2014), Weight loss composition is one-fourth fat-free mass: https://doi.org/10.1111/obr.12143
van Baak & Mariman (2023), Physiological factors affecting weight regain: https://doi.org/10.1038/s41574-023-00887-4.

The Heymsfield et al. (2014) one is the strongest, should you care to read any of them, but sorry, of course you know better.

Rosenbaum is discussing weight regain in this article, not weight maintenance on drastically reduced calories. The second is discussing where the body burns energy during weight loss, nothing to do with maintainig weight on calories below BMR, the third states that muscle is lost as well as fat during weight loss. The final one discusses psychology of weight regain.

None of that proves your point that people can eat 500 calories a day and stay the same weight. Did you even read any of them?

S210873 · 29/06/2026 22:36

oliviaAustin · 29/06/2026 09:35

Rosenbaum is discussing weight regain in this article, not weight maintenance on drastically reduced calories. The second is discussing where the body burns energy during weight loss, nothing to do with maintainig weight on calories below BMR, the third states that muscle is lost as well as fat during weight loss. The final one discusses psychology of weight regain.

None of that proves your point that people can eat 500 calories a day and stay the same weight. Did you even read any of them?

You have missed the point – yes, I read them.

oliviaAustin · 29/06/2026 22:37

S210873 · 29/06/2026 22:36

You have missed the point – yes, I read them.

Then your point hasn’t been made clearly… perhaps you should try and explain it again? Using your own words.

S210873 · 29/06/2026 23:08

Read the abstract - from the paper Abstract - yes copied from the paper direct
The increasing prevalence of obesity and its comorbidities reflects the interaction of genes that favor the storage of excess energy as fat with an environment that provides ad libitum availability of energy-dense foods and encourages an increasingly sedentary lifestyle. Although weight reduction is difficult in and of itself, anyone who has ever lost weight will confirm that it is much harder to keep the weight off once it has been lost. - The over 80% recidivism rate to preweight loss levels of body fatness after otherwise successful weight loss is due to the coordinate actions of metabolic, behavioral, neuroendocrine and autonomic responses designed to maintain body energy stores (fat) at a central nervous system-defined 'ideal'. This 'adaptive thermogenesis' creates the ideal situation for weight regain and is operant in both lean and obese individuals attempting to sustain reduced body weights. Much of this opposition to sustained weight loss is mediated by the adipocyte-derived hormone 'leptin'. The multiple systems regulating energy stores and opposing the maintenance of a reduced body weight illustrate that body energy stores in general and obesity in particular are actively 'defended' by interlocking bioenergetic and neurobiological physiologies. Important inferences can be drawn for therapeutic strategies by recognizing obesity as a disease in which the human body actively opposes the 'cure' over long periods of time beyond the initial resolution of symptomatology.

And to point it out

The over 80% recidivism rate to preweight loss levels of body fatness after otherwise successful weight loss is due to the coordinate actions of metabolic, behavioral, neuroendocrine and autonomic responses designed to maintain body energy stores (fat) at a central nervous system-defined 'ideal'. This 'adaptive thermogenesis' creates the ideal situation for weight regain and is operant in both lean and obese individuals attempting to sustain reduced body weights. Much of this opposition to sustained weight loss is mediated by the adipocyte-derived hormone 'leptin'. The multiple systems regulating energy stores and opposing the maintenance of a reduced body weight illustrate that body energy stores in general and obesity in particular are actively 'defended' by interlocking bioenergetic and neurobiological physiologies.

Your body is just protecting itself, and this lady in question has been continuously reducing her calories to try and beat it. 500 - 600 means she will likely be liquefying her muscles. It isn't healthy.

I hope this is now easier to understand. Show the papers to doctors/medics and scientists and ask them if it’s not clear. They will know this anyway - they don't need to read a published paper. On average, women need a basic amount of calories for their bodies to function; forget aesthetics. Think heart pumping, organs working, etc; if we don't eat enough for our basic metabolic system, it will turn to our muscles. That's science, not a point of view. This lady is trying to beat it but is damaging herself. People think 'scales' - it is wrong; it is adipose/fat that we should be trying to lose, not weight. Think body composition.

It isn't easy to put muscle on so hang on to everything you've got. Abstracts are all you need to read in a clinical paper unless you want lots of specifics.

InfoSecInTheCity · 08/07/2026 11:16

@ItWasNeverAboutWillPower I’ve reported you for spamming every WLI thread with advertising for your book. Pack it in, it’s annoying.

Trumptontown · 08/07/2026 11:30

InfoSecInTheCity · 08/07/2026 11:16

@ItWasNeverAboutWillPower I’ve reported you for spamming every WLI thread with advertising for your book. Pack it in, it’s annoying.

Same

takeharry · 08/07/2026 11:31

InfoSecInTheCity · 08/07/2026 11:16

@ItWasNeverAboutWillPower I’ve reported you for spamming every WLI thread with advertising for your book. Pack it in, it’s annoying.

Same, there is absolutely no need. In fact, even if I was mildly interested in your book, which I’m not, I wouldn’t even look at it because of the way you are spamming the boards. It’s really off putting and shows you up to be desperate and not nice.

Trumptontown · 08/07/2026 11:34

OP I suggest you up your calories significantly and start implementing a weight lifting programme to build muscle. It won’t happen overnight, it’s a long game, but the more muscle you have, the more calories you burn, even at rest. I don’t understand how you could be getting enough protein in when eating so few cals. I think your body doesn’t know what’s going on with the sudden weight loss, and the years of yo-yo dieting. It is possible to reset this but your body and brain need some consistency.

HelenDenver · 09/07/2026 17:23

I would love to hear some tips on how to go back to eating more calories but continuing to lose as I mentioned I have no intention to stay on this ridiculously unhealthy calorie intake.

No tips, not right now. You are unable to make yourself eat to the extent that you are eating whey protein just to get something inside you. Go back down to 2.5mg or even 1.25mg for the next couple of weeks and don’t think about losing weight whilst you find at least a few things you can stomach eating.

BlazenWeights · 09/07/2026 18:15

You’re eating 500 calories a day having a normal life and not losing weight? No chance you’re eating 500 calories. You WILL lose weight at 500 calories a day, poor thyroid or not. How long has this been going on for.

PositiveEnergyyy · 10/07/2026 16:46

Hi everyone, a quick update, I went to the GP and she won’t do a thing. She said that she can’t order any more tests as my TSH is within range and there is no medical reason I am not losing weight. She said “it is not a medial problem, so it must be that you are perimenopausal”. When I asked about how can she explain my situation, she said “I have no answer”. Despicable.

I am lifting weights 3 times a week. And yes I am counting my calories very accurately. I have been eating on average 750 cal this week and drinking 3L of water.
The scale moved but UP by 0.9 kg.
I know reading this doesn’t make any sense for many people and people are doubting what I am saying.
But it is very honestly the case with all the details I mentioned, no exaggeration. I don’t wish it on anyone.
I am at my wits end and feeling really helpless.

OP posts:
QuaintBeaker · 10/07/2026 16:54

How are you doing a 3mg dose? It goes up in 2.5mg increments

MeridaBrave · 10/07/2026 16:57

PositiveEnergyyy · 10/07/2026 16:46

Hi everyone, a quick update, I went to the GP and she won’t do a thing. She said that she can’t order any more tests as my TSH is within range and there is no medical reason I am not losing weight. She said “it is not a medial problem, so it must be that you are perimenopausal”. When I asked about how can she explain my situation, she said “I have no answer”. Despicable.

I am lifting weights 3 times a week. And yes I am counting my calories very accurately. I have been eating on average 750 cal this week and drinking 3L of water.
The scale moved but UP by 0.9 kg.
I know reading this doesn’t make any sense for many people and people are doubting what I am saying.
But it is very honestly the case with all the details I mentioned, no exaggeration. I don’t wish it on anyone.
I am at my wits end and feeling really helpless.

How long has this being going on for (no weight loss). Up to around a month it can be water retention. But at 750 cals - even with menopause should lose 1kg a week. I’d try and cut back on carbs and up the protein to around 120g a day.

HelenDenver · 10/07/2026 16:58

I went to the GP and she won’t do a thing. She said that she can’t order any more tests as my TSH is within range and there is no medical reason I am not losing weight. She said “it is not a medial problem, so it must be that you are perimenopausal”. When I asked about how can she explain my situation, she said “I have no answer”. Despicable.

Why despicable?

Kindly, you are taking this medication privately. She and the NHS are not the prescribers.

ETA if you are finding the medication unbearable, come off it. Settle down with a more normal food intake and then maybe look at Wegovy instead.

HelenDenver · 10/07/2026 17:01

QuaintBeaker · 10/07/2026 16:54

How are you doing a 3mg dose? It goes up in 2.5mg increments

You can do this by click-counting so that you don’t inject a full 5mg (or inject 2.5mg plus a bit more)