Many unwelcome changes seem to accompany us as we age, but “weight creep” is among the most insidious. I hear about it frequently from my clients; “It seems that once I hit 40 I am having a harder time keeping weight off, and why does it seem to all be going to my middle?” The two primary culprits for these changes are aging and hormones.
Beginning in our 30s we start to lose as much as 1 to 2 percent of our muscle mass each year for the rest of our lives. This decrease in lean body mass (muscle) means a decrease in the resting metabolic rate. Aging is also associated with a decrease in physical activity which may be subtle and therefore not easily perceived by the individual. This decrease in physical activity further compounds the decrease in lean body mass and our metabolism.
Menopause itself does not seem to substantially influence weight gain, but decreased estrogen levels can result in a redistribution of fat, making it more likely to accumulate in the abdomen. A 2013 study by the Mayo Clinic took a closer look at this phenomenon by comparing fat tissue in pre- and post-menopausal women of similar ages. At the cellular level they found that two enzymes that work to synthesize and store fat were more active in postmenopausal women. The drawbacks of the muffin top are more then just cosmetic: Visceral fat around our abdomens can also increase the risk of insulin resistance and cardiovascular disease.
Fortunately, research shows that we are not destined for lives of obesity and disease as we get older. One 2012 study in Climacteric, a journal of the International Menopause Society, found that weight loss can be obtained through calorie control and increased physical activity (sixty minutes/day of moderate-intensity activity). Resistance training was shown to help prevent loss of muscle and bone mass as you lose weight. Further, they found that loss of weight through diet and increased physical activity has been shown to alleviate menopausal symptoms. Estrogen therapy does not adversely affect body weight and may ameliorate the accumulation of abdominal fat.
While weight gain is common at midlife, it is not a foregone conclusion. That said, women who want to avoid midlife weight gain will have to work harder at keeping the weight off by taking in fewer calories and burning more through exercise, including resistance training which will help you to maintain and build muscle and bone as you age.