If it seems harder to prevent weight gain the older you get, you’re not imagining things. Weight gain is one of the physical changes of aging.
What’s going on? Starting around age 30, we begin to lose lean muscle. As a result, we burn fewer calories. Meanwhile, more of the energy we get from food is stored as fat. You might also notice that more fat accumulates around your waistline.
In the meantime, the body’s metabolism – the amount of energy we burn while at rest – slows down. For women, the hormonal changes of menopause (lower estrogen) also contribute to a slower metabolic rate. However, metabolism plays a smaller role in midlife weight gain than previously thought. The more likely culprit? We become less active as we age, yet we keep eating the way we did as younger adults.
Our bodies also become less responsive to insulin – the hormone that regulates blood sugar – so we feel hungry more often. We also grow resistant to the hormones that signal when we’re hungry (ghrelin) and when we’re full (leptin). Other weight-boosting factors include genetics, inadequate sleep, unhealthy eating, mental illness and side effects of certain medications (steroids, beta-blockers, antihyperglycemic drugs and others). Socioeconomic status, social relationships and other characteristics can also influence our health.
In Canada, 60% of adults are overweight or obese. Overweight people have a higher risk of various health problems, including diabetes, high blood pressure, heart disease and certain types of cancer.
Adults are considered obese if their body mass index (BMI) – calculated by dividing weight in kilograms by height in metres, squared – is 30 kg/m2 or higher. The BMI formula has limitations; it doesn’t measure muscle or fat, nor does it consider age or sex (typically, older people have more fat than younger people, and women have more fat than men). BMI doesn’t consider body composition or the location of fat (fat around the waist and abdominal organs may pose greater health risks). It also doesn’t reflect the body composition of athletes (muscle is heavier than fat), children (who are still growing), and pregnant women.
Many health professionals now consider BMI alongside two other factors. The first is waist circumference – the risk of diabetes and heart disease is higher for women with a waist size over 35 inches, and for men with a waist size over 40 inches. The second is other risk factors for health problems associated with obesity, such as heart disease. Your physician can help you determine your risk factors and suggest health-boosting lifestyle changes.
Eating a healthy diet and exercising regularly will help you prevent unwanted weight gain.
Eat three meals and two snacks a day, with plenty of fruits and vegetables. Dietitians of Canada recommends seven servings per day, including dark green, yellow or orange produce. Try filling half your plate with fruits and veggies at each meal.
More healthy-eating tips:
For more nutrition information, visit Dietitians of Canada or talk to a registered dietitian.
Staying physically active will help you keep unwanted pounds at bay, and it’s good for your mental health, too. Heart and Stroke recommends aiming for 150 minutes of physical activity at moderate to vigorous intensity each week. (Before you start an exercise regimen, consult your physician.)
Start out slowly, especially if you’ve been inactive. Try low-impact activities like walking, swimming and aerobics. Allow time to warm up and cool down. Be patient with yourself – it takes time to form new habits. Choosing activities you enjoy and putting them in your schedule will help you stick with it.