Many people who've been "on" and "off" diets over the years know that they've damaged their metabolism. When the body oscillates between undereating and overeating, it has a hard time trusting that a reasonable amount of food and nutrients will be consistently provided.
When eating patterns are irregular, the body cannot depend on a regular intake of reasonable food volume. The metabolism slows, and often digestive function is altered, damaged, and/or impaired.
To the warped brain of a chronic dieter, eating ample, well-rounded meals seems dangerous, even nonsensical. When it comes to metabolism, however, a dependable eating routine encourages dependable food processing results. Metabolism will not need to slow down to conserve nutrients out of fear or undernutrition, nor be overtaxed and inadequate for processing overnutrition.
Even if you aren't (or never will be!) a "normal" eater, it doesn't hurt to try to follow their model of sane, stable eating.
Happy new year! :)