Carbo reduction diets (Keto, Atkins et al)
Scince supports the fact that if you reduce or eliminate carbs you will lose weight. Its a fact that many car rich foods like meat and potatoes are very rich in calories. And that is the science in simple terms. However many carb rich foods are also a great source of the proteins you need to stay well. Lack of protein is an inevitable road to unwellness syndrome. You can read about that here.
Furthermore it isnt necessary to commit yourself to a carb free life to lose weight. Balance is the key. Use the food planner here to set daily objectives that dont lead to other problems.
Fasting (long periods, half day fasts et al)
Is another growing fad. Of course starving yourself is going to lead to calories deficit anf weight loss. But again it just isnt healthy. No proteins and no fibre (or significant protein and fibre diets deficits) will lead to unwellness. You can read about what a lack of fibre intake does here.
Conclusion
Yes the fads and there are a lot of them popping up all the time can lead to weight loss. But they can also lead to serious other problems especialy when maintained over the long term. We advocate a simple balance. Stealth weight gains can take years (here). And diving into radical weight loss programmes seem like a fabulous escape for many. But they are unsustainable. The chances are you will regain the weight as soon as you escape the dietary fad. Go to the planner (here) and aim for a stealthy weight loss plan. It might take longer but if you have spent years gaining weight, dont try to lose it it overnight with all the consequences the fads can have and the questionable long term maintenance after.
Go to planner here