What happens to our bodies after 40 is a trifecta of weight gain: Our hormones change, our metabolism starts to slow down and if we’re not lifting weights, we start to lose just a little more muscle every year. That muscle can help protect us from gaining weight because it’s more metabolically active. When we lose that muscle, our metabolisms drop even more. If you’re genetically predisposed to gain weight easily, that may be another strike against you. Even if you don’t actually gain weight, you may still gain inches around the waist. This weight gain can be so frustrating, it’s easy to become obsessed with losing it, starving yourself or exercising too much or maybe even looking into the latest plastic surgery procedure. But, is that really necessary? Isn’t there something we can do about gaining weight after 40? There is and it starts with understanding just what’s going on with your body. We can’t control everything about our bodies, but the more we know what’s going on, the easier it is to find some acceptance for what’s happening.
There is a multitude of reasons for weight gain after age 40. Some are genetic, some are the natural course of things, and some are due to lifestyle choices.
The four most important contributors to weight gain include:
- Hormones: One of the main culprits for weight gain is, of course, our hormones, which start to change right around the mid-30s and into the 40s.1 This change in hormones, less estrogen for women and less testosterone for men, cause the fat in our bodies fat to shift to the middle of the body while abandoning other areas of the body you could care less about. That’s one reason you may get a little fluffier around the middle while other parts of you actually get smaller.
- Heredity: Scientists have found the specific genes that determine how many fat cells we have and where they’re stored.2 This is something we can’t really change and, if you look at your parents and relatives, you’ll see those areas where your family may tend to store excess fat.
- Lower Metabolism: There are a couple of things that happen to your metabolism after the age of 40. First, your basal metabolic rate (BMR) decreases and, second, you expend less total energy (TEE) during exercise. Some experts suggest metabolism can decrease by about 5% for every decade after 40, which means you need about 60-100 fewer calories every 10 years.3 If you sit more, eat more, exercise less and deal with more stress throughout that decade, you’ll probably need even fewer calories than that. Add that to the fact that you burn fewer calories during exercise and you’ve got yourself an equation for weight gain.
- Loss of muscle: Like our metabolisms, we also start to lose muscle when we hit our 40s, experiencing a steady decline each decade. Part of this, scientists believe, is that the motor units that make up our muscles decline as we age and that those motor units don’t always fire with the same regularity.4 However, the important takeaway here is this: The biggest factor in losing muscle is the lack of physical activity, which makes exercise a crucial component when it comes to preventing muscle loss.