Your muscles are important for bone density, strength, and overall health. However, your body starts to lose muscle as you age. Building muscle can increase your metabolism and help you burn more calories at rest. Muscle also takes up less space than fat, so you can feel leaner and toned as you increase your muscle mass. Good options to increase your muscle mass include light weightlifting, body weight exercises, and Pilates.
When you’re under-rested, your appetite-regulating hormones get short-circuited, so your appetite goes into overdrive, but the hormones that tell you you’re full don’t kick in promptly. Studies also suggest that when you’re sleep-deprived, it alters the way you think about food, so you have stronger cravings for sweets and other less healthful eats.
As you enter your forties, you are also entering perimenopause, when levels of your sex hormones progesterone and estrogen decline. Besides regulating your menstrual cycle and reproductive functions, these hormones also impact restful sleep and relaxation. A decrease in progesterone and estrogen levels may lead to sleep disturbances, restlessness, and insomnia.1 Because changes in sleep patterns have been associated with weight gain, sleepless nights may make weight loss increasingly difficult.2
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.