"One of the reasons that it's difficult to lose weight in your 40s is that you are beginning to lose muscle mass, so the composition of your body tissue changes," explains Keri Peterson, MD, Women's Health advisor. "Having higher muscle mass raises your metabolism, so your body burns more calories." So when you're dealing with the opposite—less muscle mass—that means a slower metabolism. Argh.
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.
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!)
If you prefer a specific plan with specific rules, make sure it goes with your lifestyle, which, for most guys, gets increasingly complicated in your 40s with more responsibilities at work, with your family, and maybe even with your aging parents. A vegan diet can be hard to do in a healthy way if you live a grab-and-go existence. Meal prep is going to be a challenge if you’re never home long enough to cook. Don’t just pick what worked for a friend; pick what’s likely to work with your busy, over-40 lifestyle.
Alcohol adds unnecessary calories and sugar to your diet. Drinking alcohol may also increase your appetite, leading you to consume more calories.30 When you’re under the influence of alcohol, you may also be tempted to choose less nutritious options, such as processed junk foods. I recommend reducing your alcohol consumption to an occasional glass of wine or eliminating it completely.
Healthy fats such as avocados, coconut oil, extra virgin olive oil, avocado oil, and ghee have a number of benefits. These include reducing the risk of heart attack, coronary artery disease, high cholesterol, high blood pressure, cancer, diabetes, and metabolic syndrome.23,24,25,26,27 They can keep you satisfied longer, reducing the risk of overeating and snacking. Healthy eating doesn’t mean deprivation! Healthy fats taste good and improve your brain health, and so may help you feel emotionally satisfied, lowering the risk of emotional eating.28
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