Outside of low carb, my focus for a while has been fasting.
There is of course Michael Mosley and his '5:2 diet' and latterly his 'Fast 800' which are essentially fasting diets.
This chimes with me for a couple of reasons.
Firstly. My boys are 15 and 18. They are sick to the back teeth of me and my LCHF thing and essentially eat whatever I would frown at. Their breakfast is, and just about always has been, peanut butter toast with jam or honey. They will cheerfully consume whatever carbs are going when it comes to their evening meal, and indeed will grab a bag of crisps or sweets despite my frown.
And yet, they are perfect specimens of young manhood. The youngest is whip-thin, like lightning and very strong, the other muscular with a physique David Gandy would envy. Both have six packs I have never enjoyed.
You could look at them with envy (I do) and wonder at life's unfairness, until you dig a little deeper.
What's their secret?
They instinctively fast.
They eat their breakfast then typically come home with a lunchbox uneaten. One is a trainee arboriculturist, the other still at school.
When they do eat, typically they leave something on the plate. They are natural fasters, just like our ancestors were.
Secondly. Jason Fung is a HUGE proponent of fasting. His videos are inspiring, but there's another kid on the block whom I find very interesting.
It's OMAD.
Before I came across OMAD I tried an N=1 experiment. I ate a Wetherspoons traditional breakfast for 3 weeks. I ate it at 11.45am, then nothing else until the next day. Lost 7lb with no hunger. That was fasting, and OMAD may be a nuance, but the results are spectacular whatever way you choose to fast.