You eat a healthy, well-balanced diet and keep your “cheat meals” to a minimum. You’re still hitting the gym regularly. You’re doing everything right, and yet your jeans seem a little tighter and the number on your bathroom scale has slowly started to creep up. Could this unexplained and unwelcome weight gain simply be a side effect of getting older? When those extra pounds simply won’t budge, even on the strictest diet, the culprit might be fluctuating hormones.

person stepping on a scale

Hormones may be the underlying cause of stubborn weight gain.

Can hormones really cause weight gain?

Hormones are chemical messengers that are secreted by various glands in the endocrine system. These messengers travel through your bloodstream to targeted cells and organs and tell them how to function. (1) Your hormones directly influence everything from your mood to your blood pressure to the amount of calcium in your bones. Some hormones can also have a profound effect on your weight by regulating your metabolism, appetite, and insulin levels. (2) But when your hormones are out of balance, it leads to unwanted weight gain.

Hormonal weight gain doesn’t just change the way you look, it may also contribute to a variety of health problems such as cardiovascular disease, dementia, and several types of cancer. (3)(4)(5) One reason is that body fat, especially visceral fat, is metabolically active and can create hormones and chemical messengers that cause inflammation and other ill effects. (6) For example, older overweight women can produce excess estrogen in their fatty (adipose) tissue. And this can increase their risk of developing breast cancer. (7)

Did you know?
Certain hormones like cortisol help control the balance between salt and water. High cortisol levels—often a result of chronic stress—can lead to fluid retention and water weight gain. (8)

4 hormones that cause weight gain

If you are struggling with excess weight that simply won’t budge, it may be time to focus on the following four hormones. Consider talking to your doctor, nutritionist, or naturopath about testing to see if a hormonal imbalance may be at the root of your weight gain.

woman holding her head looking down

Your hormonal response to stress may have more to do with why you succumb to stress-related eating than a lack of willpower.

1. Cortisol

Often called the “stress hormone,” cortisol is a steroid hormone made in the adrenal glands and released during the fight or flight reaction. But cortisol doesn’t just help you survive real or perceived dangers. It also plays a key role in controlling blood sugar levels and regulating your metabolism. (9)(10) If you suffer from chronic stress—as many of us do—it can cause a steady stream of cortisol to flood the body, as well as a heightened response to the hormone. This can make us more vulnerable to coping mechanisms like stress-eating which can lead to weight gain. (11)

2. Estrogen

Menopausal women everywhere know that when estrogen levels drop, weight rises. Estrogen is the most important female sex hormone and is responsible for promoting fat storage during a woman’s reproductive years to maintain fertility and support a healthy pregnancy. (12) During menopause, however, the ovaries produce decreasing amounts of estrogen. As a result, fat storage shifts from subcutaneous fat in the hips and thighs to stubborn visceral fat in the abdomen. (13)

3. Insulin

Insulin is an essential hormone produced in the pancreas that moves sugar, or glucose, into your cells. Your cells can then use this sugar for energy. Insulin is also the main fat storage hormone in the body. It tells your cells to store fat and then prevents this stored fat from being broken down. (14) A diet high in ultra-processed foods can cause chronically elevated insulin levels or frequent spikes in insulin. (15) This can result in insulin resistance and weight gain, especially around the belly area. (16) Worse still, the more weight you gain, the more insulin resistant you become.

4. Thyroid hormones

Your thyroid is a small butterfly-shaped gland that sits at the base of your throat. Its excretes two primary hormones: triiodothyronine, known as T3, and thyroxine, known as T4. Under normal circumstances, T3 is converted to the more active T4 as needed to regulate your metabolic rate and turn calories and oxygen into energy. (17) Low levels of these hormones—a condition called hypothyroidism—or glitches in this conversion process, have been shown to cause weight gain, along with a slew of other symptoms. (18)(19)

person rolling up yoga mat

Yoga and meditation have both been clinically shown to positively affect hormonal balance.

How to lose hormonal weight

When traditional low-calorie diets and increased exercise don’t drive the number on your bathroom scale down, these lifestyle changes may help re-balance your hormones and trigger weight loss. As a bonus, these simple tweaks support overall health and wellbeing.

  • Limit your intake of sugar and refined carbohydrates (20)
  • Drink alcohol in moderation (21)
  • Increase your consumption of organic fruits and vegetables (22)
  • Eat sufficient amounts of high-quality protein (23)
  • Strive for seven to nine hours of high quality sleep each night (24)
  • Get regular amounts of moderate aerobic exercise (25)
  • Be aware of your stress triggers (26)
  • Practice yoga, meditation, or other relaxation techniques (27)(28)
  • Switch to natural household cleaners and personal care products free from hormone-disrupting chemicals (29)
  • Choose glass over plastic food storage containers to limit exposure to environmental estrogens (30)

Did you know?
Studies suggest that exposure to the hormone-disrupting chemicals in air pollution can increase your risk for weight gain (31)(32)

Best supplements for hormonal imbalance


This adaptogen improves the body’s resistance to chronic stress thanks to special plant chemicals known as withanolides. Withanolides serve as important hormone precursors that morph into usable human hormones when needed. (33) Because of this ability, ashwagandha modulates the way hormones function during times of stress, reducing stress-eating and the hormonal effects of cortisol. (34)

raw salmon in a black dish with omega 3 supplements on a table

The omega-3s in fish oil play an important role in hormone production and may have a direct impact on hormonal weight gain.

Fish oil

The omega-3 fatty acids found in fish oil are essential components of every cell in the body. They are also critical for hormonal balance because they are used in hormone production and function. (35) Additionally, omega-3s are very effective against inflammation, which often accompanies hormonal weight gain. (36) One specific type of omega-3 known as eicosapentaenoic acid or EPA appears to have a particularly beneficial effect on the accumulation of body fat and how well the body processes glucose. (37) Taken together, these actions may help with weight loss efforts.

Vitamin D

People who are overweight tend to have lower vitamin D levels. They are also more prone to suffer from insulin resistance. (38) But some evidence suggests that reversing these low levels with supplemental vitamin D could spur the loss of body fat and enhance weight loss.

In one 12-month study, 218 overweight women took part in a supervised low-calorie diet and exercise program. Half of the women were randomized to a vitamin D supplement and the other half received a placebo. After a year, those taking the supplement lost an average of seven pounds more than those taking the placebo. (39) One reason for this result may be due to the sunshine vitamin’s ability to reduce body fat mass. (40) Adequate vitamin D levels might also help with long-term weight maintenance. (41)

The bottom line

Losing weight is hard. When key hormones are out of whack, it can be even harder. Combining hormone-balancing supplements with weight-specific lifestyle hacks might give you the edge you need to overcome underlying hormonal problems that can stall weight loss.

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