I will be the first to admit that a Banting / Keto / Paleo diet that has meal plans restricted to the 800kCal to 1600kCal range will make you lose weight. No doubt at all. Combine that with exercise and the weight will absolutely fall off.
As with so much that we see around us every day, instant gratification leaves you with a debt of some sort that needs to be repaid. This video covers those long term impacts.
WARNING: If you are offended by strong language this video is NOT for you.