These two subjects are very different and one of them can have catastrophic results on your long term health.
Everybody wants to lose weight and lose it fast hence the crazy amount of people (mostly unqualified) from all over social media trying to sell quick fix training and diet plans and 'magical' supplements to capitalise on this.
The crazy thing about this is if I gave you two alternative pictures showing you how you would look at:
1 stone lighter on the scales
5-10% less body fat percentage
I would bet my house you would choose the less body fat percentage....Why?
Because the scales are not a true reflection of what is going on, the weight loss could just be lost water weight or if you use an extreme diet it's more than likely muscle loss (muscle weighs more than fat and this is not what you want in the long term).
Body fat percentage loss is what you are after, this will be reflected in your clothes and the mirror (providing you are doing resistance training).
Extreme weight loss doesn't just make you lose shape, it can absolutely destroy your metabolism and heavily effect your hormonal balance; meaning once you come off your diet you put the weight lost back on and more and it will be twice as hard to lose!!
Don't shatter your metabolism and hormonal balance by doing fad diets or using terrible companies like Slimming World or Weight Watchers, it's NOT easy I know but eat a balanced diet, try to be more active but most importantly USE weights and with a bit of effort and consistency you can get were you want to be....This isn't an opinion this is absolute scientific fact.
'Become The Better You'