If you were able to maintain your weight up until your 30s by eating a set amount of calories, you will likely gain weight afterwards if you continue on the same path. The reason is that people typically start to lose muscle mass at this point in their lives.
Earlier in life your body builds muscle mass, but then by about your mid 30s it begins to diminish if it is not used. When your body starts to lose muscle mass, it leads to a lower basal metabolic rate, resulting in fewer calories burned daily.
Strength training is necessary for preventing muscle loss. Examples of activities that help maintain muscle mass include push ups, sit ups, walking or hiking with some weight in a backpack, and of course going to the gym and lifting weights or using a machine with variable resistance.
But maintaining muscle mass is not the only way to keep from gaining weight after 30. Making wise food choices becomes all the more important as the years pass.
Decreasing mindless calories is a great place to begin. Resist the handful of chips when walking by a bowlful. Stop eating when you feel full, and save the leftovers for another meal. It doesn't take much to add pounds over the years, or much effort to keep it from happening.
As you get into your 30s, maintaining your muscle mass and taking extra care with what you eat can keep you trim and slim. We can be sure that some things will change as we age, but it doesn't have to be our pant size.
Megan Porter, RD