Can someone explain the physiology of what's happening to my body please?

[OhshitSharon]

I've never been very active, always hated exercise of any kind and had been extremely sedentary for at least 15 years until recently. I've been 3 stone overweight for probably the last 10 years and have never really tried to lose weight or get fit. A month ago I started a really physical cleaning job, I've literally gone from a few hundred steps per day to more like 15000 and I'm sweeping, mopping and vacuuming huge areas so it's been something of a shock to the system to say the least!

I'm obviously struggling a bit, I'm exhausted when I get home and every muscle is aching but I haven't lost any weight whatsoever which is surprising (and a bit disappointing!) and I'm wondering why that is when I'm expending so much more energy and whether anyone can explain to me (as though I'm 5 please!) the likely effects on my weight and fitness long term of this kind of increase in my activity levels? My diet hasn't really changed btw, I don't eat too much (I don't think) generally but definitely the wrong things, too many carbs, not enough veg, too much sugar but I'm autistic so food can be difficult for me and is unlikely to change.

Weight loss is almost all about food. You have to be doing pretty heroic amounts of exercise to make much difference to your weight. Firstly, you may be eating a bit more without realising it, because you're using more energy. Secondly, your body basically wants to maintain your weight, so it will compensate for the small amount of extra calories you're burning.

There have been studies done, comparing office workers with tribesmen who are on the move all day, and there's hardly any difference in the number of calories they burn. Diet is the only way to really lose weight unless you're going to actually run miles and miles every day or something.

Because you've gone from a calorie surplus to slowly put weight on to a calorie neutral because of the exercise. So you're maintaining.

15000 will feel mad after doing nothing but it's calorie impact isn't a lot proportionally to how many you burn just by existing

I suspect pp is right that the exercise is unlikely to make much difference to yoir weight. It will however be benefiting your health, fitness and likely longevity,so its still a good thing

“You can’t outrun a bad diet”
-They

Yeah. What pps said. You absolutely can outrun a bad diet, but it takes a LOT of running...plus the willpower not to demolish a handful of biscuits when you're ravenous after a 20-miler.

Clean up your diet and focus on more protein, especially earlier in the day. And especially plant based sources. Pre cooked quinoa is helpful, lots of peas and beans.

Lots of healthy fats such as avocado, nuts, seeds.

Tinned sardines and mackerel.

Loads of greens. And some berries (eg frozen is cheaper.)

The whole 30 plants a week thing, spices, herbs etc.

Fermented foods - coffee and dark chocolate counts, saukraut, plain yogurt small amounts of cheese.

Sorry I missed that you are autistic - make small changes here and there. Start with what is most realistic and doable. Easy swaps