Awful weight loss advice on Facebook

I don't think half of them are that bad though. The ones about pills or sushi for a week are kind of dumb, yes, but the rest are just about detox and there's nothing bad about that. I think that if they'd say that they were planning to go like that for the rest of their lives, then it would be bad advice, but otherwise it's honestly fine.

You don't need to 'detox' your body. That's what your liver and kidneys are for. Adequate water intake is all that is necessary to the process that your body performs by itself.
What are all these 'toxins' we keep hearing about anyway? Can anyone actually name them?
And how exactly is blended spinach juice supposed to help 'cleanse' your body? Explain the actual biological process that would occour.
How would eliminating solids from your diet assist in the removal of supposed toxins from your body? Wouldn't the minimised roughage and bulk in fact inhibit the digestive process? The thing your body does to get rid of things it doesn't want?

The while concept of 'detoxing' is flawed, unsupported by evidence and frankly dangerous.

I get your point, and it's true that the kidneys are meant for detox, but if you've been eating junk food all your life and/or not been drinking well for years, it won't work as well and the person may want to speed the cleanse up. Most foods have additives/ are processed/ etc and would therefore have more toxins than blended spinach juice. Also, there are many kinds of detoxes and not all of them involve just spinach. The key concept is to give your digestive system a rest by not taking in any heavy foods or stuff that's not good for the body while also feeding it a lot of vitamins, nutrients, and other "good" things. Biologically, under such strain, the digestive system won't be doing it's job as well, which will take a toll on the body. The organs become overloaded with toxin, which leads to acne, less fat loss, constipation, etc. An example of this is how vegans often claim to have more energy and vegan teens have almost no acne (I'd know because I am vegan). When you take in only liquids that are fruit/veg, they go quickly through your system, cleaning it, and giving it a break. The body recovers and you become healthier. Obviously, I'm not a bio professor so I don't know the minute detail, but that's the gist.

On "toxins," those are anything harmful to the body. Look at the food labels in your kitchen and I'd be surprised if you could pronounce everything. Every additive, pesticide, chemical flavoring, and food dye isn't good for you. I think we can all agree on that. Obviously, it's impossible not to take in any at all, but the idea is to clean your body a bit every now and then.

You talk about "roughage and bulk" and how it'll only "inhibit the digestive process," but foods that are too heavy or bulky only strain the stomach and are hard to digest. Juice, on the other hand, barely requires any digestion. The body has been adapted to digest and detox over several millenia, which means that unless you eat like a caveman, it won't be perfect. The things we put in our foods today are beyond our bodies capabilities. Also, our body is ethnicity specific, which is why if I, for example, eat a lot of Indian food my stomach will hurt, but my friend's won't. Not all the foods we eat today are able to be digested well by the body.

You say that there is no evidence and that it's "dangerous," but if there's not evidence, how can you know that it's dangerous? Hundreds of people have detoxed and it's worked out fine for them. There's a lot of personal reports saying that it's been good for them (I can vouch that detox is beneficial as well). Obviously, there are people for whom this won't work, but you have to take into account that our bodies are all different and that there's no set rules for how to detox. Everyone does it differently so it's not going to have the same results necessarily. Also, there's scientific proof that toxin can lead to cancer and major illnesses, so getting rid of that can't possibly have a negative effect. Overall, excessive detox will be harmful, but for a few days to a week is fine.