One of the most common complaints I hear from my older female clients is how hard it is to maintain a healthy body weight after menopause. Women who have been slim their whole lives suddenly find they’re growing a belly, while those who’ve been fighting the battle of the bulge for as long as they can remember, often reach the point of simply giving up because no diet that ever worked for them before, however temporarily, seems to make the slightest difference to their expanding girth.
There are several reasons why aging women gain weight more readily, especially around the midsection. Firstly, as the ovaries wind down their production of estrogen, the ratio between estrogen and testosterone alters, causing women to store fat more readily around their abdomens. The ‘pear shape’ of the premenopausal women morphs into the ‘apple shape’ that is typically seen in overweight men.
Secondly, our basal metabolic rate (BMR) – the amount of calories or kilojoules our bodies burn each just to maintain basic functions – declines about 1-2% each decade, after we hit 20.
As a consequence of both the drop in BMR and decreased physical activity, total energy expenditure (TEE) drops by roughly 150 calories per day per decade. What this means is that a 60 year old woman needs around 600 fewer calories per day than she did when she was 20, and if she doesn’t cut back on her calorie intake, she will inevitably gain weight.
The decline in metabolic rate is believed to be due either to declining muscle mass and increased fat mass, and/or a decreased metabolic rate within muscle tissue, and/or an unavoidable loss of or metabolically active organ tissue.
On top of the hormonal and metabolic changes, some women are genetically predisposed to weight gain, regardless of whether they eat more than their slender sisters. While this may seem grossly unfair, those who store fat readily are simply the descendants of ancient ancestors whose genetics gave them a survival advantage in times of food shortage, which was a regular occurrence throughout our evolutionary history.
However, research published in the journal Menopause in October 2018 provides good news to women who are genetically prone to obesity: physical activity effectively neutralises the ‘fat genes’.
The researchers studied 8206 women of European ancestry who were enrolled in the Women’s Health Initiative, an ongoing epidemiological (population follow-up) study which is most well known for having identified that postmenopausal women who took hormone replacement therapy were at increased risk of coronary heart disease, stroke and breast cancer.
They identified 95 single nucleotide polymorphisms (SNPs), or gene variants that were strongly and consistently associated with weight gain. They also gathered data on the women’s body mass index (BMI), a standard way of assessing whether a person is at a healthy weight for their height, or is overweight or underweight; and their average daily activity level.
When all the data were crunched, the researchers discovered that among women who were physically active, the effect of ‘fat genes’ was effectively neutralised. That is, women whose genes predisposed them to weight gain weighed much the same as their skinny-gened sisters as long as they participated in regular recreational physical activity, including brisk walking. And the more active they were, the lower their BMI.
The anti-fat gene effect became more pronounced the older the women got, such that women aged 70+ benefited the most from physical activity if they had been ‘cursed’ with genes that predispose to weight gain.
The bottom line is that physical activity becomes more important the older we get, but sadly, most people become progressively more sedentary as the years go by.
Exercise preserves muscle and bone mass, which decreases the risk of bone fractures; reduces the risk of dementia, cardiovascular disease and several types of cancer; and lifts mood.
And now we have evidence that it can cancel out the effects of ‘fat genes’! Quite simply, if you’re not physically active on a regular – preferably daily – basis, you’re sabotaging your capacity to be your healthiest, happiest self.
Leave A Response