Crash diets?

angiechimpanzee

Crash dieters are seen as foolish mostly because they have crappy eating habits (the ones that made them fat in the first place), & the quick fix diets they go on only serve as temporary successes because once they end it, they usually return to their old crappy way of eating and gain back not only the water weight, but ALSO the fat they lost during the diet.

But WHAT IF someone already has good eating habits formed - they chose nutrient-dense, low calorie foods by default, they reach for almonds instead of chips by default, they prefer oatmeal in the mornings to sugary cereals or fattening pastries.
Would that person still be stupid for trying a short term crash diet, just to see some quick losses for whatever reason? If so, why? Even if, lets say, they lose 8lbs on a one week crash diet, and only 3 pounds of it is fat, and the other 5 is water/food/waste that will return within the next few weeks. They still lost 3 pounds of fat. And although it might seem like they've "gained most of it back" in the weeks afterwards, if their eating habits are still good after the diet, the weight they gain back SHOULD theoretically only be the 5lbs of water. The rest should be able to be kept off.

I've done huge amounts of research on the "starvation mode" myth, and found that yes, it is indeed a myth. The body metabolizes in the following order - incoming food, then glycogen stores, THEN fat stores, THEN muscle. So even if a person is on a starvation diet for a mere week, if they have ample amounts of fat stored, they shouldn't lose very much muscle at all.

I know that most people who do crash diets do so because they lack the knowledge/patience to lose weight the gradual, sustainable way, by changing their habits permanently. But what if someone already has good habits, but still wants a quick fix once in a blue moon, for an event or a vacation or something? Where's the harm in that?