Since Kaplods already handled the part about low carb plans, I'm just going to focus on this.

There is no such thing as starvation mode as mentioned.

When we eat fewer calories than we expend our body burns its excess storage. However, our bodies are very efficient machines. They get used to the number of calories they are given -and- the types of exercises done, and get very good at performing the tasks it's used to on a certain number of calories.

This is why when someone hits a plateau one of the first things suggested is "mix things up!" Do a new exercise, or add intensity. Add a few calories, change the number of times you eat, subtract a few calories, try different types of meals. Etc. Etc.

Mixing things up keeps the body from getting used to a routine. Sometimes a change is all we really need to bust through a plateau.

One of the OTHER reasons for plateaus is a lapse in vigilance. This is not everyone, mind you, but sometimes people wonder why they aren't losing weight, only to realize (after they're asked how their tracking is going, or how their exercise is going) that they haven't been tracking...or exercising...or they've been sneaking in an extra cheat meal each week.

if you don't eat enough... your body does turn on its self. it will eat muscle. you don't want that.