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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

64 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:
SunnySunnyDayz · 28/06/2026 16:24

WLI do more than just lower appetite, they reduce inflammation and increase insulin sensitivity.

Up your dose and the amount you are eating and see how you get on. Go to GP if nothing changes.

S210873 · 28/06/2026 16:27

KittytheHare · 28/06/2026 16:17

Thanks for sharing this - it’s prompted me to get an amino supplement. I know I’m not eating enough naturally in my diet.

100% try Forzet – make sure it has all nine essential amino acids. My sister is a dietician and said thsi is in all the right ratios.

PositiveEnergyyy · 28/06/2026 16:39

Thank you so so so so much everyone.
To clarify: I eat 80 grams of lean protein a day sometimes 100 grams and drink 3 L of water and stay low carb. No alcohol at all. I count my calories meticulously so I am sure about the calories intake. Yes, the walk burns about 300 cal. I am 3 month 1.5 wk in so have been trying different strategies the last 4-5 weeks. Nothing worked until I dropped my calorie intake to 500-600 cal as an experiment. It is too unhealthy and I am sooo tired even though I am not hungry.
I had yo-yo dieted over the years and that certainly messed up my metabolism but had hoped the MJ will help with this.

I stayed on 3 mg as I have v good appetite suppression and everyone’s advice on MN was to go up the doses slowly and only if the current dose doesn’t work. I also read here on MN that people who went on higher doses didn’t necessarily lose more/faster if they had good appetite suppression on the previous doses.
I am 13st 5 lb and 5 6 tall.

I have NO intention on staying at such low calorie intake. It is too unhealthy and that why I am asking for help.

OP posts:
takeharry · 28/06/2026 16:43

See a doctor.

RoseField1 · 28/06/2026 16:48

PositiveEnergyyy · 28/06/2026 16:39

Thank you so so so so much everyone.
To clarify: I eat 80 grams of lean protein a day sometimes 100 grams and drink 3 L of water and stay low carb. No alcohol at all. I count my calories meticulously so I am sure about the calories intake. Yes, the walk burns about 300 cal. I am 3 month 1.5 wk in so have been trying different strategies the last 4-5 weeks. Nothing worked until I dropped my calorie intake to 500-600 cal as an experiment. It is too unhealthy and I am sooo tired even though I am not hungry.
I had yo-yo dieted over the years and that certainly messed up my metabolism but had hoped the MJ will help with this.

I stayed on 3 mg as I have v good appetite suppression and everyone’s advice on MN was to go up the doses slowly and only if the current dose doesn’t work. I also read here on MN that people who went on higher doses didn’t necessarily lose more/faster if they had good appetite suppression on the previous doses.
I am 13st 5 lb and 5 6 tall.

I have NO intention on staying at such low calorie intake. It is too unhealthy and that why I am asking for help.

How long have you been eating 500 calories for? How do you eat 100g protein and stay under 5-600 calories? What else are you eating?

ElectoralControversy · 28/06/2026 16:51

If you ate enough plain chicken breast to give you 90g protein, that would be almost 500cals by itself?

S210873 · 28/06/2026 17:00

PositiveEnergyyy · 28/06/2026 16:39

Thank you so so so so much everyone.
To clarify: I eat 80 grams of lean protein a day sometimes 100 grams and drink 3 L of water and stay low carb. No alcohol at all. I count my calories meticulously so I am sure about the calories intake. Yes, the walk burns about 300 cal. I am 3 month 1.5 wk in so have been trying different strategies the last 4-5 weeks. Nothing worked until I dropped my calorie intake to 500-600 cal as an experiment. It is too unhealthy and I am sooo tired even though I am not hungry.
I had yo-yo dieted over the years and that certainly messed up my metabolism but had hoped the MJ will help with this.

I stayed on 3 mg as I have v good appetite suppression and everyone’s advice on MN was to go up the doses slowly and only if the current dose doesn’t work. I also read here on MN that people who went on higher doses didn’t necessarily lose more/faster if they had good appetite suppression on the previous doses.
I am 13st 5 lb and 5 6 tall.

I have NO intention on staying at such low calorie intake. It is too unhealthy and that why I am asking for help.

I called my sister who set up weight programmes for the NHS. I’ve DM’d you. She reminded me that eating less than 1400 calories a day (for me) would liquify my muscles and my metabolic rate would just decrease due to metabolic adaptation. She used to have people on 2 year programs (no drugs) just on shakes i think and then they'd introduce normal healthy meals at stages.

Skybluepinky · 28/06/2026 17:14

The very low calorie shake diets of the 80’s that caused people to have heart attacks as their body was breaking down their heart muscle were similar calories to what you say you are eating. How accurate is your tracking, are you weighing and measuring everything you eat and drink?

HeSaidSheSaidTheyAllSaid · 28/06/2026 17:28

What do you eat in a typical day when only having 500-600 calories?

S210873 · 28/06/2026 17:31

Skybluepinky · 28/06/2026 17:14

The very low calorie shake diets of the 80’s that caused people to have heart attacks as their body was breaking down their heart muscle were similar calories to what you say you are eating. How accurate is your tracking, are you weighing and measuring everything you eat and drink?

Exactly, and even now people forget up to 40% of weight lost on GLP1 can be muscle (lean muscle mass, clinical evidence validation exists, including your heart, if you dnt eat enough on GLP1. This was being discussed in my gym where the owners were saying a few of the GLP1 takers were saying they were feeling they were losing their cardiovascular strength. I think they meant the running and bike stuff, as they do HIT there.

InfoSecInTheCity · 28/06/2026 18:08

I don’t see how your calorie and protein counts can possibly be accurate.

  • 1 g of protein = 4 kcal
  • 80 g protein = 320 kcal
  • 100 g protein = 400 kcal

so at most that leaves you with 180 calories a day for drinks, veg, carbs, fat, fibre etc.

redboxerclub · 28/06/2026 18:15

how much did you weigh when you started? 20stone??16stone? Or 10stone and just want to loose a bit?

Isobel201 · 28/06/2026 18:16

I've managed to lose 3 stone on Mounjaro in a year without doing much exercise at all, I can't achieve 10,000 steps a day, but I just did what I could.

Sunshineandgrapefruit · 28/06/2026 18:17

Your body is in starvation mode and probably holding onto all the weight it can. If 500 Cal is right that's not an amount the human body can survive on for long and continuing to eat at this level will lead to it becoming even harder to shift any weight long term. Eat more, and eat properly. Sleep properly and exercise and drink enough water. Don't weigh yourself and don't calorie count. After a few months reassess.

S210873 · 28/06/2026 18:22

"Yo-yo dieting, or weight cycling, triggers a true physiological response known as adaptive thermogenesis. When you severely restrict calories, your body burns fewer calories to conserve energy. This slower metabolism, combined with hormonal shifts, makes it harder to lose weight and easier to regain." Look it up. Adaptive thermogenesis is metabolic adaptation. No wonder we have a booming dieting industry

somanychristmaslights · 28/06/2026 18:48

If you genuinely are eating 500 cals a day and not losing weight, you need to go to the doctors as that’s not normal at all.

PositiveEnergyyy · 28/06/2026 19:03

I really appreciate all the responses.
I have been on this 500-600 cal situation for the last 5 days since I moved to 3 mg from 2.5 mg, partially because I have even more appetite suppression after increasing the MJ dose and to test whether my body could shake up the plateau. I have no doubt that I suffer from adaptive thermogenesis.
I was just under 15 stones when I started.

For people who are asking what I have been eating to get the 80-100 grams of protein, I eat lots and lots of prawns and some Skyr or I take whey protein isolate which has 25 grams of protein for about 100 cal. I never eat any ready shakes or ready made food and only took the whey protein when I really struggled to eat.

I am assuming my appetite will return tomorrow as the effect of MJ wears off.

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.

OP posts:
RoseField1 · 28/06/2026 19:07

Reduce your dose back to 2.5, cut out alcohol and eat three small meals a day.

S210873 · 28/06/2026 19:09

PositiveEnergyyy · 28/06/2026 19:03

I really appreciate all the responses.
I have been on this 500-600 cal situation for the last 5 days since I moved to 3 mg from 2.5 mg, partially because I have even more appetite suppression after increasing the MJ dose and to test whether my body could shake up the plateau. I have no doubt that I suffer from adaptive thermogenesis.
I was just under 15 stones when I started.

For people who are asking what I have been eating to get the 80-100 grams of protein, I eat lots and lots of prawns and some Skyr or I take whey protein isolate which has 25 grams of protein for about 100 cal. I never eat any ready shakes or ready made food and only took the whey protein when I really struggled to eat.

I am assuming my appetite will return tomorrow as the effect of MJ wears off.

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.

Do you want me to see if I can get a 10-minute call with my sis for free? I dm'd you. She is a dietitian. I saw a horrible incident once on holiday with a lady/mum collapsing - she wasn't eating. I know you are, but you know it's not enough.

PositiveEnergyyy · 28/06/2026 19:11

S210873 · 28/06/2026 19:09

Do you want me to see if I can get a 10-minute call with my sis for free? I dm'd you. She is a dietitian. I saw a horrible incident once on holiday with a lady/mum collapsing - she wasn't eating. I know you are, but you know it's not enough.

Thank you, that is super kind. I DMed you back some minutes ago.

OP posts:
hahabahbag · 28/06/2026 19:17

You need proper medical care, it’s not enough to maintain muscle mass if you’re counting calories correctly.

DumpedByText · 28/06/2026 19:21

I'm on 3.75 mg, 12 weeks in, lost 2st and eat 1300 a day. Sounds like you're not eating enough calories, trying upping them for a week. 3.75mg is perfect for for me as well.

MeridaBrave · 28/06/2026 19:36

I’d be worried you are losing muscle with calories and presumably protein that low. My advice would be to join a gym and start doing resistance exercise, eg the weights machines. Make sure you eat 100g of protein a day even if some of it comes from shakes.

MxCactus · 28/06/2026 19:55

What's a typical day of eating look like for you?

500 cals is way too low. I'm only 10 stone and I eat 1,300 cals a day to lose weight. There's either something going on with your thyroid, or your miscounting your calories, or you actually are losing weight!

oliviaAustin · 28/06/2026 20:12

S210873 · 28/06/2026 13:07

Your metabolic rate slows down; that's the issue. People don't realise that when you lose weight, you lose muscle as well- a scientific fact. There was a paper recently talking about essential amino acids for GLP1 users to help preserve muscle, let me see if i can find it

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