The main benefit is mental though. I feel in control and no longer thinking about food every minute of the day. After 40 odd years of set up to fail diets and losing/gaining the same 4 stones, I feel like I've finally been let in on the secret.
THIS - PLUS all the other more tangible benefits. Cutting out sugar and UPF has literally changed my life and my whole attitude to food. I was only slightly overweight, but I no longer have to think about dieting or 'how can I lose the extra 5, 10, whatever pounds. And I managed to reverse my pre-diabetes, so HUGE health benefits right there.
The book which changed my life was The Sugar Solution by Dr Mark Hyman. I am sure there are others that convey similar information, but I found this both comprehensive and yet easy to understand as it explains the physiological process of sugar addiction and the benefits of giving it up really well.
There is a compabion book called The 10-Day Detox Diet which contains a lot of useful recipes - a new way of eating. I also found a YouTube nutritionist called Dr Becky Gillaspy very useful - lots of 10-minute sessions about reducing sugar and eating healthily.
It boils down to eating mostly plants plus lean protein and some healthy fats. Small amounts of complex/unrefined carbs are okay too, as is eating moderate amounts of fruit, especially berries - but go easy on bananas, pineapples, melons and other fruit that is high in sugar.
And yes, I do allow myself the occasional glass of wine, an icecream, or even a slice of cake. Becuase I now feel in control, I can let go every now and again.