Changes in your activity levels are one of the main reasons that losing weight after 40 may be more challenging than before. Like many women, you may be putting others first and simply not finding time to exercise. You may also notice that your joints can no longer handle the same activities as before. However, a lack of exercise can lead to muscle loss and fat gain.
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.