Target of Healthy BMI

[TreeCake]

Over the last few months I seem to have gained a lot of weight and I now weigh 66kg and I am 5'2". My BMI is 26 and very nearly in the obese region. I'm still in size 12 clothes (and squeezing into some old 10s!).
According to BMI, the upper end of what I should be is 57kg.
I really want to lose some weight but don't think I've ever been 57kg as an adult, even at my slimmest. I need to really focus on what I'm eating now to get there. I don't exercise. I can manage around 70,000 steps per week.
Any pointers for where to start please? How do I work out how many calories I should be eating?

Look up a TDEE calculator and put your details in there.

TDEE is the calories you use to live while doing your normal level of exercise. If you eat less than this then you should lose weight. The approximate number is to eat 500 calories a day less than your TDEE to lose 1lb a week.

Then start logging your calories in something like MyFitnessPal and make sure you're drinking plenty of water.

A BMI of 26 isn't anywhere near obese, which starts at 30 for White British people and 27.5 for Black, Asian and Middle Eastern people (I'm not 100% sure on other ethnic backgrounds).

70,000 steps a week and reducing calories seems like a decent place to start. Might intermittent fasting also help?

Which BMI calc did you use. At your height and weight your BMI is 26.6. From the NHS calc the range is 45.9 - 61.9.

I'm 5'3 and managed to lose 11kg over the past year. I was at the top end of healthy BMI and got it down to 19.2, despite never having been this slim in my adult life and thinking it was unachievable. I'm 54.

I cut down massively on saturated fat and carbs, cut out UPF which I didn't eat much of anyway and cut sugar and alcohol to almost nothing.

In reality this meant switching to skimmed milk, no longer eating butter, only eating small amounts of cheese occasionally, limiting pasta/rice/bread/ potatoes to small quantities and cutting out cake/biscuits/ice cream.

I still eat 3 meals a day and a snack and don't get hungry, I eat to appetite. My portion sizes are not huge and I eat more during the day and a smaller dinner.

Typical breakfast: kefir or porridge with fruit and nuts/seeds. Decaf skimmed milk latte. Occasionally a boiled egg, fruit and a slice of sourdough bread.

Typical lunch: Big salad with lots of chopped raw veg and some protein (eg. nuts, low fat cheese, egg, tinned fish). One fruit. Very occasionally a low fat cheese sandwich and fruit, usually if I'm out walking and bringing a packed lunch.

Typical afternoon snack: handful nuts, I medjool date, 1 square 90% chocolate.

Typical dinner such as baked fish, bean stew, lean beef bolognase, lentil curry with big portion side vegetables. Occasionally a little of the pasta/rice/potato/bread that the rest of the family eat with dinner, but usually just the main dish plus veg.

I always refuse biscuits/cake/ice cream when offered. The rest of the family tend to eat these at the weekend and I used to too. Now I've decided I prefer being slim the the enjoyment of 5 minutes of eating cake.

BMI is a very blunt tool. If you want to loose weight because you are feeling uncomfortable, unhealthy then go for it. Don't pin everything on being within your BMI range. I lost 4 stone with Weightwatchers many moons ago and I made it down to 10st12lb, this was the absolute top of my "healthy" BMI range. I really had to fight the last two pounds for months. It was easier to maintain a couple of pounds higher than that and I was healthy and fit. Use it as a rough guide, but don't feel like you've failed if you don't hit the goal but physically you look /feel well.

Really helpful responses here, thank you.
I am mixed (white & black Caribbean) so apparently should weigh slightly less which I hadn't known till this week. I also have PCOS but haven't previously had too much of an issue with weight. It's really piled on lately, I was quite shocked when I weighed myself as I thought I was around 60kg.