Reduced metabolism on injections

[Butterfly44]

I’ve just started on Mounjuro, and eating so much less, under 1000 cals a day. I presume this puts the body into starvation mode and reduces my metabolism. And that a persons Basal metabolic rate BMR at rest also reduces. So my question is if being calorie deficient causes a decrease in metabolism, how can we increase weight loss. What solutions have you found?

Starvation mode is mostly nonsense tbh in the way that most people believe it works. For your average obese dieter, it’s irrelevant. People talk about it generally because they aren’t being honest with themselves about how much they are eating and blame ‘starvation mode’ for slow weight loss, but that’s not how it works. You see it on the diet threads on here a lot. Those people are almost certainly just eating too much to lose weight, not starving themselves as they believe.

Personally I lost 4.5 stone on MJ without worrying about it and am maintaining at a normal maintenance calorie intake, as expected (for me that’s around 1750 calories a day, which is what the various TDEE calculators suggest too).

Starvation mode doesn’t exist

First few weeks can be tough to get enough calories in if you are responding to Mounjaro, but you should try to with calorie dense foods such as mixed nuts.

This is why 2nd pens/5mg gets a bad rep because the body starts to react to far to low calories and you stop losing weight. You also risk negative effects like hair loss as you body redirects resources to critical functions (and hair isn't one of them).

Starvation mode isn't a thing otherwise people wouldn't become malnourished and people with eating disorders wouldn't get to an unhealthy weight

I don't think I buy the whole starvation mode thing! Last year I lost about 2 stone v quickly by drastically dropping calories and then had a full body MOT. I was told my metabolic age was 27 and given I'm late 40s, that was pretty good! I don't think my metabolism was impacted by the drastic weight loss and hugely reduced calories!

I've now been on mj for 4 months. I plan to get another full body MOT end of summer after I reach my goal and am keen to see what my metabolic age will be. But I don't think it will have gone substantially up...

The question is, how your metabolism will work once you’re off the MJ and will this cause yo-yo effect. Metabolism slows down due to insufficient calorie intake or prolonged fasting. That’s the fact.

While starvation mode isn't an accurate term, metabolic adaptation is very real. That's why when dieting it's important to actually eat enough and achieve steady (sustainable!) weight loss.

So, OP, your solution is to eat enough. As in, eat your TDEE minus 500 calories. 1000 calories is not enough, you will do yourself more harm than good.

I have been weighing and logging my food intake with myfitnesspal on and off since December 2012 and every single day for the past 1135 days. I have also weighed myself every four weeks for over 3 years, and logged my weight and measurements on a spread sheet. Giving a clear picture of how many calories I ate and how much weight I have lost during that time.

In September 2023 when the NHS was no longer able to get hold of liraglutide I had to go back to to counting carb grams and injecting insulin units before eating anything containing carbohydrates. The diabetes consultant promised to move me onto Mounjaro when it became available, but said that could take 10 months.

Knowing that insulin is obesogenic and not wanting to sabotage my progress I decided to follow the advice of the myfitnsspal website and restrict my calories to 1400/day for a month.

It was very difficult to go from eating between 1800 and 2000 calories/day down to 1400. I was hungry all the time, so hungry that it was difficult to get to sleep because my stomach felt as if it was being gnawed by rats. I stuck with it hoping to continue the 1 - 3kg/month weight loss I'd got used to seeing. It took every last smidgen of willpower and when I climbed on the scales I was expecting reward for my superhuman efforts. I felt completely crushed when it turned out that I'd only managed to lose 0.4 kg after what so much prolonged effort.

I had to rethink the strategy, no way I could keep that up for another month without going off the rails. Sooner or later the NHS were going to start prescribing an alternative to liraglutide and I'd be able ditch the insulin. So in the meantime I decided to cut myself some slack, aim for maintenance rather than weight loss, and increase my calorie allowance to 1760/day. Which still required a lot of willpower, but didn't involve being so hungry it kept me awake at night.

When I weighed myself at the end of the second month, expecting to have maybe gained a bit, while desperately hoping for no change, I had lost another 0.5kg! So eating more calories had resulted in an extra 100g weight loss.

The month after that (purely in the interest of science) I allowed myself to eat between 1700 and 1900/day. Four weeks later I climbed on the scales and saw that once again I had lost exactly half a kilo.

In case anyone is wondering how my physical activity levels varied during those three months, I'm disabled, I need sticks or a walking frame to hobble between my bedroom, kitchen, bathroom and living room. My smart watch tells me I average 1500 steps on a good day, just dragging myself from bed to toilet, to shower, to kitchen, to armchair in a slow and painful loop, accompanied by a constant litany of swearing in symphony with the pains. So it's not like I squeezed a bit of hill running into my daily routine and boosted my energy expenditure on the second and third months.

I would have probably continued experimenting with my calorie intake to see how many extra calories I could scoff while still injecting insulin and maintaining the weight loss of half a kilo every 28 days. Except I found out it was possible to buy semaglutide on private prescription, and was finally able to ditch the insulin. Hallelujah!

Without extra insulin snaffling glucose from my bloodstream and converting it directly into fat I was able to eat between 1800 and 1900 calories/day over next four week period, and lose 2kg.

So my personal experience is that there certainly is a starvation mode where my body does everything possible to discourage me from losing weight. It manifests as painful, gnawing hunger pangs, the inability to keep warm, and constant fixation on food, what I want to eat, what I will be allowed to eat at my next meal, what I will eat tomorrow etc etc. There was a huge difference in how I felt on 1400 calories compared to when I went back up to 1760/day, I was still hungry before meals, but it wasn't the only thing I would think about, and I wasn't having to wear bedsocks and wristwarmers because my extremities were so cold they were like blocks of ice.

So the "simple equation" of calories in versus calories out, minus calorie expenditure turns out not to be right, at least in my case. Perhaps it's the same other women with useless thyroids, PCOS, insulin resistance, metabolic syndrome and a load of autoimmune ailments? Especially after they hit menopause. It's not research money has been poured into us and our pathetic ailments.

Really interesting @stealthsquirrelnutkinI don’t get how eating more calories or intake close to your TDEE causes weight loss. Goes against my understanding which is why I posed the question.

Diets say to eat calorie deficient to lose weight, yet they also say metabolism can reduce as a consequence which slows down weight loss.

Eating at a deficit isn't the problem, it's eating at an extreme deficit for a long time and the issues that causes.

Eating above your BMR (basal metabolic rate - calories you burn just by existing) but below your TDEE (which includes BMR + daily movement) = healthy weight loss. If you are an average adult human then your BMR will be above 1000 by a fair bit, especially if you are overweight enough to require GLP-1 drugs. The bigger you are the more energy required to keep you alive. Of course your TDEE/BMR requirements will reduce as your size reduces.

If you are eating very low calorie for a sustained amount of time then around 40% of your weight loss will be due to muscle loss/wastage. Less muscle means your BMR calories are lower. Your body will burn fewer calories just existing. That's just the beginning of metabolic adaptation.

"Metabolic adaptation, also known as adaptive thermogenesis, is a physiological response where the body becomes more efficient at using energy, burning fewer calories, and potentially hindering weight loss or promoting weight regain after a period of calorie restriction or weight loss."

That's why it is SO IMPORTANT to eat enough when dieting AND hit your protein goals. It is especially important when taking Mounjaro so you can lose less muscle. It is also why mounjaro users are encouraged to strength/resistance train, not just do cardio. More muscle = higher calorie burn just existing.

Eating enough to fuel your body but not enough that your body stores excess energy as fat is the key. That means eating 500 calories less than your TDEE to lose a sustainable 1lb a week. 1lb of fat equals aproximately 3500 calories. Being sustainable and able to maintain your weight loss for the rest of your life is the goal here.

@stealthsquirrelnutkin what epic data you have collected : am sure a researcher could benefit from this! Thank you for sharing. Have you played around with macros / types of food?

I have been losing 0.5 - 1kg a week still eating a chocolate bar or cake every day as now when I have something high carb it doesn’t set off a cascade of binging. I wonder if this is what it is like for thin friends who can have a 800 calorie Gail’s almond croissant for breakfast but then eat lightly for the rest of the day.

@SickThank you. That’s so well explained! I will eat more protein and incorporate dumbbell exercises.

I wonder therefore with the fast 800 diet which candidates essentially ate 800 cals a day for 12 weeks, how they did when stopping and returning to a more normal diet.

@Butterfly44 another method to try is monitoring your calorie intake weekly instead of daily, and varying your daily calories to prevent metabolic adaptation. Switching between lower and higher calorie days can also feel more sustainable.

I've seen similar recommendations for women trying to fast or do IM, to help manage hormones.

I'm not cut out for fasting, but I have tried calorie cycling and found it easier than daily restrictions. (Full disclosure - I've never managed any eating plan for a sustained period of time, hence being on WLIs).

Hope you find a system that works for you.

@SmallSoupcon Thanks. Varying daily calorie intake might help. Definitely got hormones against me being hypothyroid and menopausal, so that’s slowing my metabolism too. So on mounjaro I’m eating little but not losing much, but early days so will keep at it :) Determined to shift kgs and get body healthier.

I recommend the book Why We Eat Too Much by Dr Andrew Jenkinson that explains why harsh calorie restriction doesn’t work and the metabolic adaptation if you attempt it (and will always gain weight again).

I've done it twice and each time gained the weight back and then some.

It's ok for a quick fix if you have a small amount to lose (like after an indulgent holiday or something) but for those of who have a had a years long battle with obesity it just doesn't work. Extremely calorie restricted diets don't produce sustainable long term food habits.

That's part of the reason mounjaro is so amazing, it helps you make better choices without feeling deprived. 95% of the time I don't want sugary and fatty foods anymore, I actively want veggies and healthy options. It makes me want to nourish and fuel my body. I can see a future where I will be able to keep making these choices even when I don't have mounjaro.

And honestly, OP, once you start eating enough I think you will feel amazing. I used to think starving myself was the only way to lose weight but I honestly feel incredible these days. I have energy, my skin looks amazing, my head feels clear, my body no longer aches. I still have 6 stone left to lose!