The human body is made to run off a gas tank of fat reserves, not to be tethered to an extension cord of continuous eating. Eating every couple hours is historically impossible, and just on that basis one can reason it's likely maladaptive. You eat a proper meal, insulin levels spike to put the energy in fat and glycogen, insulin levels drop, then you switch over to running on the fat and glycogen. You are not built to always stay in the "post-meal" state of elevated insulin and fat storage.
There is no basis to the idea that eating frequently boosts metabolism. I think the practice really has origins in the body building community where they want somewhat elevated insulin levels in order to pack on mass. Body builders pack on fat along with muscle and then shed the fat later for competition.
Some recent studies indicate that the same life extending benefits of calorie restriction can be had by eating only every other day. The point is to spend much time with low insulin levels.
> I've lost 25 pounds of body fat and gained 7 pounds of muscle mass in the last 14 weeks using this approach.
Notice how you never hear from people who have stayed thin for years by counting calories. The research indicates it just doesn't work. Even in the short term we only get these anecdotes of success and the data indicates it's not very effective.