This word “metabolism” was something I knew about but it never really impacted me personally until I reached middle age. That's about the time I realized I was gaining a bit of weight. Metabolism... Midlife... They're just words. But why do they affect us so and what exactly does it all mean? Well technically “metabolism” is the word to describe all of the biochemical reactions in your body; like taking the nutrients in the foods you eat and mixing it with the oxygen you breathe to create the fuel everything you physically do (from running a marathon to napping on the sofa). Your body, even as we pass midlife, has an incredible ability to grow, heal, and generally stay alive. And without this amazing biochemistry simple things like thinking or even having a personality would not be possible. Metabolism takes charge of your energy and allows you to stay active physically while reserving fuel for the autonomic activities that we usually forget about because they run in the background (e.g. heart beat, wound healing, processing of nutrients & toxins, etc). And metabolism does what most if us dread: allows storage of excess energy (fat) for later use. The problem is, metabolism affects each of us differently based on many variables. So, like a circus clown juggling while riding a unicycle on a high-wire, you put all of these processes together - and hopefully you'll have a metabolism that doesn't work too quickly or too slowly - but, just right. Which brings us to the balancing act called metabolic rate. This is the measure of how fast your metabolism works and is measured in calories (yup, those calories!). The calories you eat can go to one of three places:
Physical Work (i.e. exercise and other activity)
Heat (i.e. from all those biochemical reactions)
Storage (i.e. extra leftover “un-burned” calories stored as fat).
So, the more calories you burn physically as work or creating heat, the easier it is to lose weight - and keep it off because there will be fewer “leftover” calories to store for later. There are a couple of different ways to measure metabolic rate. One is the “resting metabolic rate” (RMR) which is how much energy your body uses when you're not being physically active. The other is the “total daily energy expenditure” (TDEE) which measures both the resting metabolic rate as well as the energy used for “work” (e.g. exercise) throughout a 24-hour period. What affects your metabolic rate? In a nutshell: more than you probably thought! The thyroid gland is probably the first to consider. It regulates the hormones that tell your body to “speed up” your metabolism. Of course, the more thyroid hormone there is the faster things will work and the more calories you'll burn. But that's not the only thing that affects your metabolic rate. Muscle matters, too! Muscles that actively move and do work need more energy than fat does. So the more lean muscle you have the more energy your body will burn and the higher your metabolic rate will be. Even when you're not working out. This is exactly why I am adamant about weight training as you age. You want muscles not only to be able to carry your carcass from one place to another, but to also help burn off those extra calories you ate when you passed by the refrigerator... Speaking of eating - the type of foods you eat also affect your metabolic rate! Your body actually burns calories to absorb, digest, and metabolize your food. This is called the “thermic effect of food” (TEF). You can use it to your advantage when you understand how your body metabolizes foods differently. Fats, for example increase your TEF by 0-3%; carbs increase it by 5-10%, and protein increases it by 15-30%. By trading some of your fat or carbs for lean protein you can slightly increase your metabolic rate. Another bonus of boosting protein consumption is that your muscles need it to grow. By working them out and feeding them what they need they will help you not only lose weight but keep it off, too. Lastly, there is the mind-body connection. Plenty of research shows the influence that things like stress and lack of sleep can have on the metabolic rate. This is all just the tip of the iceberg when it comes to metabolism and how so many different things can work to increase (or decrease) your metabolic rate. But here's what I think is most important: exercise. It's important especially as we age. Don’t forget to exercise! It's the quickest way to improve your health, combat a sluggish metabolism, and reshape your outlook on life. That and smart eating. Until next time - Keep moving toward a better you!