It's that time of year again. The holidays are winding down, winter has set in, and your waistline has gotten larger. You vow to get more exercise, lose weight, be healthier in the new year. But before you do something crazy, like insert a feeding tube up your nose (there's a diet for that) here's a quick review of some fad diets.

Fad diets are usually recognizable by certain criteria, according to a 2004 paper by the University of Kentucky Cooperative Extension. They often involve miracle foods, bizarre quantities of one type of food, have rigid menus and tout rapid weight loss. They rarely include any type of increased physical activity.

Some popular categories of fad diets include low- or no-carbohydrate diets popularized by the Atkins Diet; high carb, high fiber diets that avoid proteins and fats; liquid diets, diet pills, extreme low-calorie diets, novelty diets that promote specific foods, and pre-measured diets, such as Jenny Craig or Nutrisystem.

Some of these diets use valid concepts or have strategies that may work if part of an overall healthy diet and exercise plan. Others...not so much.

So, before you head out to buy a state-of-the-art juicer, fill your pantry with superfoods and weight-loss shakes or buy a tapeworm pill (more on that later), remember the common themes that most doctors and nutritionists preach when it comes to weight loss. Eat a variety of healthy foods, don't eat too much, and exercise. This list may actually inspire you.

Here are 30 fad diets.