Please help me with why I am not losing weight

[IrisJoy]

I have been using my fitness pal since last summer and have lost 11.5kgs. I want to lose 12 in total. I was so nearly there, I had 500 grams to go. I have stuck to within 1200 cals religiously for the last 3 weeks (including exercise allowance). But I am gaining weight! I have now gained over 1kg this week. I am mit sure why.
I have recently stepped up my exercise so I would like to think it is muscle, but a friend says that I am not eating enough calories to be putting on muscle.
It’s not my cycle as this has been through and after my period.
My bmi is currently about 21.2 and I wanted to get it down to 20. So I can understand if this is my body’s natural weight and I struggle to lose the last little bit, but to be gaining it baffles me! I don’t think I am underestimating the calories I am eating because I am eating the same or less than I was when I lost the rest of the weight.

Any ideas? TIA

Suspect you’ve now reached a level that your body needs much less than 1200 to loose weight. The smaller you are, the less calories you need to maintain or loose. So it’s a descending number.

You don't need to lose anymore weight and 1200 calories is too restrictive

Instead focus on the other health benefits exercise is bringing you e.g better mental health, strength, mobility etc

Set performance goals and don't just see exercise as punishment for what you ate

I'm a Strength and Conditioning Coach and if I was your coach I'd be giving you this advice

Whenever I step up my exercise I always gain a little to begin with (sometimes a lot!) because your muscles can retain water after strenuous exercise.

Your body needs more than 1200 calories a day for essential function. At some point, it's going to fight back to protect itself.

Have you ever been the weight you are targeting?

It's most likely the muscles retaining water, it'll settle down.
But really with that bmi it will probably only gone off extremely slowly now

Thanks for all your help.
The exercise I do for enjoyment. It’s not actually to do with the food thing. It’s upping at the moment due to training plan.
I have decided to up my calorie intake to 1490 but concentrate on everything I eat being nutritious, and not to worry too much about that last kg.

That sounds like a good idea.

You’ve come up with an arbitrary number that your body didn’t get the memo on! Good idea to just concentrate on nutrition and forget about the numbers. I would ditch the scales altogether if I were you. It sounds like you have a positive relationship with exercise and yes you will gain if you are exercising more and eating enough so weighing yourself obsessively won’t be helpful.

IrisJoy firstly CONGRATULATIONS!!!! you have lost an awesome amount of weight . Please don't focus too much on the last pound/500g - you can gain or lose more than twice that just by doing a poo or having a pint of water or (in my case) breathing!

Around 10 years ago I wasn't losing weight and started to weigh myself 3 times a day - first thing, last thing and when I got home from work around 2pm. My lightest time was always 2pm and my heaviest was first thing. I am the only person I know who gains weight whilst sleeping! I wasn't losing weight because I was eating too much 'because I was burning it off exercising' except I was eating way more than I burnt exercising! But my main point is your weight will fluctuate massively - go by how your clothes fit or set yourself some exercise targets instead.

How much do you weigh now, OP?
And how many minutes of moderate-intense exercise do you do each week?

I weigh 51-53 kgs and do roughly 3hours exercise per week (jogging or light weights hiit etc)

mmm the online calories suggest that (if you're 40yo) you'd need about 1850/day. So something is off, probably you're overcounting calories intake or maybe it is high water retention.

a friend says that I am not eating enough calories to be putting on muscle.

i don't know what the blocked mechanism is supposed to be in that claim..

The amount of body that can be converted from fat in an otherwise healthy 'active' person who stays at same rough weight, is really small, and the weight per volume of muscle vs. fat is so small difference... you'd end up having to convert something dramatic like 8 litres of fat to 9 litres muscle for "fat to muscle conversion" to explain the weight difference -- I don't think you did that in 3 weeks, so friend is right but for wrong reasons.

So you've pretty much reached your target?