Your metabolic rate naturally continues to decline 5 percent each decade once you hit 40.3 Your resting metabolic rate (RMR) determines how many calories you just to survive. It is determined by a variety of chemical reactions inside your body. These reactions rely on your mitochondrial function and sodium-potassium pumps. Your mitochondria help to create energy, while your sodium-potassium pumps generate muscle contractions and nerve impulses.4,5,6,7,8 Both of these processes become less effective over the years and slow your metabolism.9,10 If you eat more than your RMR yet lead a sedentary life, you set yourself up for weight gain.
Sometimes the medicines you're taking for other issues, such as high blood pressure and antidepressant meds, can increase your weight or keep you from losing it, says Dr. Stanford. Ask your doctor if your weight concerns could be side effects of the prescriptions you're getting filled. Often, there are other formulations that can be effective but wouldn't have those side effects for you.
If you eat healthy and exercise regularly and still can’t lose weight, your thyroid might not be working like it should. This happens in about 5% of people, and it's most common in women and people over 60. In addition to weight gain, it can also cause fatigue, joint or muscle pain, and depression. Medications can help, so get it checked if you think it might be an issue.