There are many fads in dieting but the point about fads is that they are fads. In other words, they may work for one or two individuals, but that’s not the point.

The definition of ‘work’ is actually: can it sell? can it sell thousands or tens of thousands of books or dvds or plans or whatever?

And actually, by that measure, many fad diets may work: they will generate thousands of dollars for their creators; and you can tell by looking at the top Amazon diet products which those are.

I remember about 30 years ago, my mother was involved in a fad that involved wearing a black plastic bin liner that was supposed to encourage weight loss by enhancing water loss. Never mind that this was fruitless because our bodies required water, it was doomed to never succeed because it lacked on particular characteristic of successful programs: it wasn’t convenient to walk around all day (or even part of the day) wearing a black bin liner!

So diets have to have certain requirements:

1. They must be believable and authentic;
2. They must be actionable by ordinary individuals;
3. They must offer a degree of convenience or at least as little inconvenience as possible;
4. They must have something to sell; and
5. They must also be bearable to some extent.

It’s amazing how many diet fads fail on at least one of these points. So I wonder whether the Protein Shake diet can be any more successful. It qualifies, but I wonder about point 5 – whether you can bear a low calorie shake diet for more than about 3 days, my wife’s personal best!