Go into the diet or weight loss area of any bookstore and you are sure to run across various books on metabolism. Inevitably the topic of metabolism is packed with fear. Our fitness culture handles metabolism as if it's this fragile thing that can break and degrade if we so much as miss a workout or skip a meal or two. The image of walking through a full scale rifle with a five foot tall Ming vase comes to mind. I used to fall for this fear myself, but now I believe differently.
For one thing, the biggest impacts on your metabolism are things you can not change and in other cases change very slowly. These include your genetics, age, gender, height and how much lean body mass you're carrying around.
Ask your doctor about changes in metabolism and you're likely to hear numbers like a decrease of 1-2% per year or something around that. So a change in your metabolism is not like the radical shifts our diet and exercise books like you to believe. Fearing a drastically changing metabolism is like fearing a run away glacier.
In reality our metabolism is not like a Ming vase that's so fragile and frail, but it's more like a chunk of rock that only changes and erodes with lots of time and consistent pressure. Skipping a meal or missing a workout will not cause your metabolism to come crashing down and shatter beyond repair.
So do not worry. Eat good food, get some sleep and stay active. Unless you have a drastic and constant change in your diet or exercise plan (or you shrink a foot or two), your metabolism is not going anywhere anytime soon.