If you're like most Americans age 50-plus, your waistline is six centimeters wider than it was in your 20s or 30s, and the numbers on your scale reflect this, too. We can all tick off the reasons: genetic predisposition, supersized portions, too much sitting and not enough moving. But there's another theory circulating through the weight-loss world: hormonal imbalance. And “balancing” those hormones is the promise behind books like The Hormone Fix, diet programs such as BeBalanced Hormone Weight Loss Centers and countless dietary supplements like Female Balance or DIM, a compound marketed to men as a “testosterone protector."
To suss out whether your hormones are colluding with your fat cells, first a little Hormones 101. Made by our bodies, these chemical messengers have wide-ranging effects: controlling growth, developing sex organs, directing blood sugar levels and, yes, influencing body weight, body fat and muscle mass.
Levels of certain hormones change with age and they can occasionally cause weight gain, says Kenneth Burman, M.D., director of endocrinology at MedStar Washington Hospital Center and professor of medicine at Georgetown University, both in Washington, D.C. (Endocrinology is the medical specialty that treats hormone-related diseases.) But, he says, “For the vast majority of people who are overweight or have obesity, hormones are not main the cause.”
According to Burman and other leading endocrinologists, here is the complete list of hormones that may, or may not, affect your body fat as you age.
What they do: The thyroid, a gland that sits in the front your neck, releases hormones with wide-ranging effects — everything from stimulating fetal growth to regulating heart rate and body temperature to dictating metabolic rate (the rate at which you burn calories).
The body weight connection:
- If you're hyperthyroid, like 1.2 percent of Americans, the gland is overactive, secreting too much hormone which gooses metabolism and can lead to a dramatic weight loss. That might sound pretty great, but the condition puts your heart, bones and eyes at risk.
- Nearly 5 percent of Americans (higher rates for those age 60-plus) are hypothyroid, with an underactive gland that produces too little hormone, slowing metabolic rate.
Hormone Rx: If you have either of these conditions (measured by blood tests for levels of thyroid hormones and thyroid-stimulating hormone — TSH), and your clinician recommends medication, here's what you can expect: “You'll probably return to your usual weight if you were hyperthyroid, and if you were hypothyroid, you'll probably lose a few pounds. But medication is not going to reverse a big weight gain because it's not likely a major cause of your weight gain,” says Burman.
What is does: One of the main sex hormones for women, the hormone triggers puberty in girls and regulates fertility. Estrogen also helps protect the cardiovascular system and bones and influences mood.
The body weight connection: Estrogen may affect your shape, nudging fat to the hips and thighs. “That's why, when estrogen levels plummet with menopause, women tend to gain more ‘visceral’ fat that lodges deep in the abdomen. But whether menopause itself makes you gain weight overall isn't clear,” says Burman.
Hormone Rx: Because menopause is a natural stage of life and not a disease, there's usually no need for hormone replacement therapy unless symptoms like hot flashes and insomnia are taking a bite out of your quality of life. “But this is a time to be extra conscientious about nutrition, calorie intake and exercise to keep visceral fat in check. In excess, this fat raises risk for heart disease, type 2 diabetes and other conditions,” says Burman.