2. Exercise More. Contrary to what your body may want to do, you must exercise more regularly as you age, not less! If you’re finding yourself slowing down, gradually start ramping it back up. It’s not a good idea to go from taking an occasional walk to running a 10K. That’s a fast track to getting an injury. But start finding ways to fit more physical activity to your life. The more you exercise, the more insulin sensitive you become (that’s the opposite of insulin resistant!)
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.
Before you try anything else, make sure there isn’t an underlying factor interfering with your weight loss, like a thyroid condition. Did you know that nearly 1 in 5 adults over 40 suffer from thyroid problems that can interfere with weight loss? Your thyroid is the main regulator of your body’s metabolism, so having an over or under-active thyroid gland (hyper or hypothyroidism) can truly interfere with weight loss. Talk to your doctor if you’re having trouble losing weight and also experiencing any of the following symptoms of a thyroid disorder:
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.
“Has something happened — a change in relationship or job? Has that affected the times that you’re eating, how and what you’re eating, and who you’re eating with? Those changes in eating nutritionally can affect your weight,” Weiner said. “If you used to eat with other people, you maybe had more vegetables. Alone, you may be eating less healthy foods.”
Why that’s so important: “The more muscle we have, the more calories we burn,” Kirkpatrick says. Even if it doesn't actually help you lose weight, it can help keep you from gaining it—along with all the other good things it does for your body, mind, and life. Lots of over-40 guys like HIIT, since its compressed timeframe ends up having a low impact on your schedule.
In your forties, your body may have an increasingly difficult time digesting carbohydrates, which may lead to weight gain. Living a stressful life can lead to an increase in the stress-hormone called cortisol, which can make you more prone to gaining belly fat. Estrogen loss may also lead to fat redistribution in your body and cause belly fat gain.11
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.
It's a myth that eating at night leads to weight gain, Palinksi-Wade points out; it's more about what you're eating at night that can be an issue when it comes to weight management. "Since most of us don’t have a salad for a midnight snack, if you find you tend to eat calorie-dense, high-sugar foods in the evening (like a bowl of ice cream) setting guidelines as to when to stop eating may help you to lose weight faster."
People naturally lose muscle after 40, especially women after menopause. Because muscle burns more calories than fat, this can slow down your metabolism and make it harder to shake those stubborn pounds. Strength-training exercises -- lifting weights or doing body-weight exercises, like push-ups and squats -- at least twice a week can help you keep those muscles.