I started off overweight, am now slim but not thin, and have maintained my slim weight for 3 and a half years. This has all been done on a low carb/high fat diet with no fasting. I say no fasting, but I do skip breakfasts and eat 2 meals in a 6 or 7 hour window. A coffee with cream fills me up from getting out of bed to lunch time. (plus a cup of tea mid morning).
After losing all my weight (33% of my body weight) I found it challenging to stop losing, but I did find the right balance and it has continued to work for me. I increased my fats mainly from protein sources such as eggs and cheese, and actually reduced my carbs at the same time. I also started having the coffee and cream for breakfast and occasionally as a go-to comfort food, but not often, became very generous with the mayonnaise, and have a glass of red wine in the evenings.
It did require some effort at first. I kept a detailed food diary on a spread sheet that included portion sizes, used my bathroom scales and my glucose meter, and worked out what I needed to do. Despite the reduction in carbs, I upped my calories from 1200 to 1800+. Once my weight stabilised, I didn't need to be so meticulous in calorie counting. I now know instinctively what I can eat to maintain my weight and my non-diabetic glucose levels. If my weight starts to trend upwards, sadly I have to do without the wine for a while.
I am 5ft 4ins. BMI 21.