Musicgirl I disagree. Admittedly I have never been grossly obese, but I put on 2 stone along with the menopause.
I lost that 2 stone 8 years ago on the 5.2 diet. Not only that but I have done it without being on a diet for life and without it being very, very boring constantly thinking about everything I put in my mouth. Once I had lost the weight I adjusted my eating style and patternand portion size to keep my weight stable and now rarely even think about what i am eating. My tastes have changed, I do not like sweet things. so can watch other people tucking into cakes and biscuits without having any desire to eat any myself. I am not exceptional, lots of people teach themselves to do this.
Similarly, I also understand the problem of those with a genetic makeup that leads to weight gain. Such a gene runs in DH's family. He has always struggled to keep his weight down, even when he eats no more than I do.
Our DD was born with a big round tummy and it was even bigger by the time she was one. I and my Health Visitor consulted regularly,. The HV said she did not know what to advise because i was already doing all the right things, the hospital put her on a diet that meant her eating far more than she was accustomed to and she put on 7lbs in 6 weeks, which I told them would happen - then they blamed me for not following the rules.
One doctor suggested that perhaps my daughter went round all the neighbours getting them to feed her, rather like a stray dog. Thankfully this suggestion left me speechless, otherwise I might have been so scathingly rude to him, the school might have banned me. Yet she had the smallest appetite in the family and was the most active. Looking back in DH's family, we can trace family members with DDs build and problems through 4 generations of hard working farming and tradesmen.
Personally I think much of current day obesity is not the result of over eating but the result of the regular consumption of UPFs (Ultra-processed foods) that contain vast quantities of chemicals, emulsifiers, stabilisers, and maize sugar products, that denature the food we eat so that it has a long shelf life, can produce hundreds of thousands of absolutely identical products and which no other generation of humans before ours have ever eaten and are damaging our digestive systems.