“Wait until you hit 40…” is commonly heard in discussions about weight management. Yes, the traditional thought is that our metabolisms are burning hotter as we grow, level off, and then decrease when hitting ‘middle-age.' This is when the weight becomes more difficult to control. A new study, Daily energy expenditure through the human life course, says not so fast. News outlets are all over this. Some have attention-grabbing headlines and other science-based outlets have interviewed the authors to get more insight. Here is a link to the actual study abstract, but if you want to read the whole paper, there is a fee. A ScienceDaily article includes excerpts from author interviews.
Although you can search for other outlets referencing the study and pontificating on it, the Pointe’s Fitness Blog has its own thoughts to relay.
The gist of the study, and why it’s making the news, is that metabolism, when controlling for factors such as growth and development in younger years and loss of muscle mass in older adults, reaches a steady state of sorts in our 20s and remains so through our 50s. Say what?! Beyond that, when controlling for activity levels, there is still a metabolic pattern by age. Babies’ metabolisms are crazy high through their first birthdays and then they slowly decline reaching the steady state that remains from our 20s until after age 60. After 60, another ongoing gradual decrease in metabolism takes place on into our 90s.
So, if we take this recent information and apply it to weight management, one might throw their hands up and say, “Well, if I can’t control how my body burns calories, why put forth the effort.” Let’s pump the brakes on that thought. There is no doubt this study provides a new outlook on metabolism, but to make the jump from cellular level metabolism patterns by age, to having no control, is overreacting. Article headlines are already using words like “shocking.” When applying this information to weight management, particularly in our 30s, 40s, and 50s, it is really less than shocking. It actually supports the importance of appropriate activity levels and diet, which is a battle cry of all preventative health professionals.
The term "middle-age spread" refers to the additional pounds added during our 30s, 40s, and 50s. It is easy to blame those pounds on aging and a decreasing metabolism. But just because there is a correlation, doesn’t indicate causation. If we are being honest with ourselves, the middle-age spread has more to do with lifestyle than metabolism. This study drives that point home even more. There are many factors/conditions on an individual basis that affect metabolism. On the population as a whole, however, extra weight is due to lack of physical activity and a diet with more calories than are being expended. That’s simple, right? Simple in concept, but so much more difficult to counteract in practice.
Most of us that add weight do so over 10-20 years in our 30s and 40s. We look back on high school pictures and wonder what happened. Life happened. More responsibilities draw away from any focus we did have on a healthy, more active lifestyle. Maybe the phrase should change from “wait until you hit 40” to “wait until you start adulting.”