A combination of hormonal and metabolic differences makes losing weight more difficult for women than for men.
Women often struggle to lose weight. To make matters worse, it often seems as if their male partners, brothers, and friends can simply change their diet or lifestyle and the pounds will fall off. Meanwhile, many women who have made the same changes are still waiting for results. Research shows we're not imagining this phenomenon. In a systematic review of 58 studies that directly compared diet-only and diet/exercise interventions in women and men, 10 of the studies found that men lost more weight than women on both types of weight-loss interventions.
This is largely due to the crucial differences in metabolism between men and women. Our body composition, hormones, pregnancy, and much more can make weight loss and weight management more difficult.
The metabolic differences between women and men
Research has identified several factors that explain why women's bodies are more likely to accumulate body fat and have difficulty losing weight:
Increased cravings and appetite: Research suggests that the neurobiological mechanisms underlying cravings and appetite differ between men and women. For example, a 2009 study published in the Proceedings of the National Academy of Sciences found that when men and women smelled and tasted foods such as pizza and cake, brain scans showed significant activity in regions that control food cravings. However, when they were asked to suppress their hunger and cravings, only men showed a relative decrease in activity in the brain regions activated by food.
Pregnancy causes some women to lag behind: About half of pregnant women gain weight during pregnancy or retain the excess weight for at least a year after delivery. The hormone prolactin, which increases during pregnancy and lactation, is known to affect appetite regulation systems and, through its effect on behavioral pathways in the gut and brain, promotes weight gain, obesity, and metabolic syndrome. Studies also show that weight gain during pregnancy is an independent factor in long-term weight gain and obesity in women.
The role of sex hormones and weight
In one way or another, all of the metabolic differences mentioned above can be traced back to one and the same thing: hormones. In women, for example, sex hormones like estrogen and progesterone play a dominant role in body composition, and hormones are what trigger hunger and cravings.
How does it work? I generally like to compare hormones to a symphony—the official conductor of the orchestra is the brain. Two particularly important parts of the brain are the hypothalamus and the pituitary gland. These parts of the brain communicate with organs to produce hormones. When these brain regions function normally, common weight-loss strategies, such as increased physical activity and lower calorie intake, work.
However, poor nutrition, excessive alcohol consumption, and excessive stress can affect the hypothalamus and pituitary gland, which in turn disrupts hormonal balance. These hormones can individually counteract weight loss, but they can also interact in ways that make weight loss more difficult.
Take estrogen, for example. Estrogen is the major female sex hormone. It is responsible for female sexual and reproductive development. It also plays an important role in weight and body composition, although its specific effects are complex and vary depending on the life stage. A study examining the relationship between estrogen and insulin found that too high or too low estrogen levels can lead to rapid changes in overall body metabolism, including fat distribution, insulin sensitivity, energy expenditure, and food intake.
Estrogen dominance [a high level of estrogen relative to progesterone] leads to weight gain around the waist, hips, and buttocks and promotes insulin resistance. In my clinical experience, too much estrogen is the main reason women, regardless of age, have difficulty losing weight. Estrogen dominance is associated with conditions such as PCOS, insulin resistance, and endometriosis.
But too low estrogen levels relative to progesterone can also be problematic for metabolism. Declining estrogen levels can also lead to weight gain, usually around the middle, and a decrease in lean body mass. This typically occurs during the transition to menopause. And why? Sex hormones like estrogen, and especially estrogen receptors, play an important role in fat cell activity and fat distribution. Studies show that women gain an average of 12 pounds within eight years of the onset of menopause.
Women's hormone levels also change dramatically during their cycle, which can lead to weight fluctuations. One study has shown that women burn an average of 106 fewer calories per day during the follicular phase (before ovulation) than during the luteal phase (after ovulation), regardless of physical activity. Other studies show that the body's insulin response changes during the menstrual cycle. For example, insulin sensitivity is higher during the follicular phase and decreases during the luteal phase.
Furthermore, studies show that premenstrual cravings are a widespread problem and can contribute significantly to cardiometabolic side effects such as high blood sugar and visceral fat accumulation associated with obesity.
Support hormone and weight management
There are ways to help the body maintain its hormonal balance, making it easier to lose weight and keep it off.
Here are some good ways to get started.
1. Focus on strength training
Women are naturally disadvantaged when it comes to calorie expenditure during the day, but certain types of exercise—especially resistance training—can increase basal metabolic rate. A systematic review of more than 18 peer-reviewed articles comparing the effects of cardiovascular exercise and resistance training found that aerobic exercise had no effect on resting metabolic rate, while resistance training increased resting metabolic rate on average compared to control subjects.
2. Focus on healthy protein
You may need to reduce calories and increase certain macronutrients like protein during menopause. Here's a list of our favorite protein sources:
- Nuts (macadamia nuts, walnuts)
- Seeds (pumpkin, flax, hemp)
- Eggs (from cage-free chickens)
- Wild-caught fish low in heavy metals (salmon, mackerel, sardines, trout)
- Shellfish (crabs, mussels, oysters, scallops, shrimp)
- Free-range poultry (preferably dark meat with skin)
- Free-range and grass-fed meat
3. Avoid hormone-disrupting foods
Research shows that consuming lots of trans fats, refined carbohydrates, and added sugar can impair fertility and female hormone balance by decreasing progesterone, a hormone that regulates follicle development and part of the ovulation process. Alcohol is another known hormone disruptor. Studies of pre- and postmenopausal women have shown a general association between hot flashes and alcohol consumption. And one study showed that average salivary estradiol levels throughout the menstrual cycle were 18 percent higher in women who consumed more than 10 grams of alcohol per day than in women who consumed less than 10 grams of alcohol per day. To promote hormonal balance, limit your consumption of alcohol, as well as beverages and foods with added sugar and processed carbohydrates, such as sodas, juices, and most packaged foods.
4. Manage stress
There is a clear link between stress and weight gain. In a controlled study, participants who supplemented their eight-week weight-loss program with mindfulness-based stress management significantly reduced their BMI (-3.1) compared to the control group (-1.7), even though they were only instructed in the techniques once a week. The program included diaphragmatic breathing, progressive muscle relaxation, and guided visualization. There's no magic number for how often or for how long you should perform these exercises, but one frequently cited study showed positive changes in emotion regulation and mood with just 13 minutes of meditation per day for eight weeks.
5. Professional help
The interplay between various hormones and metabolic health is extremely complex, and if you're struggling to lose weight, it may be worthwhile to consult a doctor trained in integrative and functional medicine. These doctors look at the whole person, examining metabolic health, gut health, hormone levels, as well as diet, supplements, exercise, and stress management.
6. Control your weight the healthy way with Hello Inside.
The best way to understand how your diet and behavior affect your metabolic health—and your weight—is with a continuous glucose monitor and an app like Hello Inside to help you understand your data.
