Sarah, 51, is concerned about her 7 kg (15 lb) weight gain over the past 5 years, despite the fact that she exercises regularly and has had no notable changes in her diet. She is experiencing menopause symptoms, including irregular periods and frequent hot flashes. She would like to understand why she is gaining weight and wants to explore solutions to mitigate this trend.
Why Midlife Often Means Weight Gain for Women
Midlife (40-65 years) is characterized by physical, psychological, and social changes, rooted in the combination of the natural aging process and the menopause transition. During this stage of life, 60%-70% of women report weight gain with predominant central (abdominal) fat deposition.
Large longitudinal cohort studies, such as the Study of Women's Health Across the Nation (SWAN) and the Nurses' Health Study, show that in midlife, women gain 0.4-0.7 kg (0.9- 1.5 lb) per year, regardless of age, race/ethnicity, or socioeconomic and menopause status. Aging, rather than menopause, is the primary cause of this weight gain, with adults generally gaining 0.5-1 kg (1.1-2.2 lb) annually.
Although we generally cut back on caloric consumption as we age, we also decrease our energy expenditure as a result of reduced physical activity and muscle mass (remarkably, from the age of 30 years, muscle mass decreases by 3%-8% per decade). This largely explains why we gain weight later in life.
Women in midlife also experience a more specific phenomenon in the form of changes to their body composition. The hormonal changes of the menopause transition are associated with more precipitous decrease in lean mass and increase in fat deposition, particularly in the central distribution. Similarly, the presence of vasomotor symptoms increases the risk for weight gain and body composition changes among women in midlife, as they are associated with decreased physical activity and poor sleep quality.
Weight gain during midlife contributes to the onset or progression of overweight and obesity. The accumulation of excess adiposity increases the susceptibility to develop cardiometabolic dysfunction and other diseases, risks that are amplified by age- and menopause-specific physiologic and metabolic changes. Excess adiposity is an important risk factor for cardiovascular disease, the leading cause of death among women, and breast cancer, the most common cancer in women.
A Three-Part Plan for Addressing Midlife Weight Gain
Clinicians should aim to provide midlife women with a holistic weight management approach that includes:
Weight gain prevention.A successful approach begins with educating women in their late 30s and early 40s about the risks of weight gain and body composition changes that can accompany aging and menopause.
Although there are no specific guidelines in this area, data in premenopausal women support that a hypocaloric diet consisting of 1300 calories daily, with reduced fat and cholesterol, can prevent weight gain during the menopause transition.
After menopause, a low-fat diet paired with an increased intake of vegetables, fruits, and whole grains, and without purposeful caloric restriction, could mitigate weight gain. Although important for health, exercise alone generally does not mitigate weight gain, further emphasizing the need for patients to implement dietary changes.
Management of menopause symptoms. It is estimated that approximately 80% of menopausal women experience vasomotor symptoms that can last up to a decade. Given the association between vasomotor symptoms and weight gain and changes in body composition, these symptoms should be treated effectively.
Menopause hormone therapy remains the standard of care for vasomotor symptoms. When hormone therapy is contraindicated, clinicians should consider nonhormonal treatment options. Favor weight-neutral pharmacologic agents (eg, venlafaxine, desvenlafaxine, oxybutynin, and fezolinetant) over weight gain–promoting ones (eg, gabapentin, clonidine, paroxetine, citalopram, and escitalopram). Also consider nonpharmacologic options like cognitive-behavioral therapy and hypnosis to alleviate menopausal symptoms.
Evidence-based overweight and obesity treatment. Screen for overweight and obesity at every medical visit throughout a woman's lifespan. Although body mass index (BMI) is the universal screening tool for overweight and obesity, given the changes in body composition in midlife women, other measures, such as waist-to-hip ratio or whole-body adiposity measurement, should be considered in clinical practice.
In women with overweight and obesity, implement a comprehensive lifestyle intervention consisting of medical nutrition therapy, exercise, and behavior modification. A caloric deficit, generally a 500-kcal reduction from the calculated or measured energy expenditure or 1500 kcal/d, is key for weight loss. During a weight loss intervention, protein intake ≥ 30% of the daily caloric intake or ≥ 1.2 g/kg of body weight mitigates muscle mass loss, which is of particular importance as we age.
In midlife women, cognitive-behavioral therapy for weight loss not only results in weight reduction but is also associated with improvements in restrained eating and quality of life.
Remarkably, due to the metabolic and behavioral adaptations in response to caloric restriction and weight loss, most midlife women undergoing a lifestyle-based weight loss intervention will achieve only a modest 5%-7% total body weight loss, which is not likely to be sustained in the long term. As such, in conjunction with lifestyle changes, most women will benefit from a second-level therapy, such as antiobesity medications, endoscopic bariatric procedures, and/or metabolic/bariatric surgery. These should be considered on the basis of BMI, the presence of adiposity-associated diseases, and the weight loss goals.
Conclusion
The weight gain Sarah experienced is a common age-related occurrence in midlife women, caused by decreased energy expenditure. It is often accompanied by menopause-related fat redistribution resulting in increased abdominal adiposity accumulation. Awareness and preventive measures are crucial to managing weight and reducing the risk for overweight- and obesity-related health issues in midlife women. In Sarah's case, she was recommended to implement a comprehensive weight management program to mitigate weight gain. This program includes lifestyle modification and treatment of vasomotor symptoms. If Sarah meets criteria for overweight or obesity, additional tools could be considered to effectively treat excess adiposity.
