Before I begin this blog, I must give complete and total credit for the term Metabolic Momentum to Bill Hartman - if he's smart, he'll trademark it ASAP ;)
All I know is this - for the past 2-3 months I've trained pretty hard, consistently, and ate reasonably well. My diet hasn't been 100% perfect, but pretty good overall. However, the other day I had a light training session but my diet was pretty darn bad - I don't remember what all I ate, but I know it wasn't healthy and I finished the day off with a small Blizzard from Dairy Queen (conveniently located less than 1 minute from my house).
So I put on 3 pounds at least that day - right?
That's what I would've figured - but in fact the opposite was true. I actually LOST a pound that day, bringing me to a current low of 204 pounds.
Essentially, metabolic momentum occurs when you've trained your ass off and ate really well for an extended period of time. John Berardi refers to this (or something along these lines) as G-Flux.
In fact, it's not rocket science at all - the phrase "Eat Less, Move More" comes to mind immediately. There's nothing wrong with eating carbs, or having a dessert from time to time - the key is that these are considered "treats" and don't occur on a daily basis. Couple this with a regimented and reasonably hard training program and you're good to go.
I'm not going to drone on and on about this, just understand that the further you are away from your goal, the more dialed in you have to be to accrue some Metabolic Momentum. Your metabolism is slow as molasses and you need to do everything in your power to get it rolling. Get strict about your diet and training to really crank things up.
As you get closer to your goal, you can (but don't need to) slow down and enjoy the process a little bit. I've essentially hit my goal of being in the low 200's, so unless I want to take it a notch further I'm okay with where I'm at. My metabolism is cranking pretty good, so I have a little bit more leeway in my diet now than I did over the past couple of months. In essence, it's my reward for being a good boy for a while now.
I hope this all makes sense - dial in your diet, train hard, and develop some Metabolic Momentum to help get (and stay!) in great shape!