It’s usually not just due to losing muscle mass over time (more on that later). "It's multifactorial," says Fatima Stanford, MD, MPH, obesity medicine physician scientist at Massachusetts General Hospital and Harvard Medical School. Numerous factors can sneak up on you and help you gain or hold onto weight, including your lifestyle, your food, your biology, and your sleep habits. The good news in that is that there are also numerous ways to tackle getting your weight to where you want it—you don't have to force yourself into one approach, and you get to choose what works for you.
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.
Pay attention to what you are eating. Read labels and ensure your foods are organic, nutrient-dense, and anti-inflammatory. Avoid eating in front of the TV, while standing up, and when busy with other tasks. Keep a regular eating schedule. If you are craving something, check-in with yourself to see if you are truly hungry or just thirsty, stressed, or bored.
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.