Menopause generally occurs in a woman's mid-40s to early 50s when reproductive hormones, such as oestrogen and progesterone, naturally decline. These hormonal changes are accompanied by a number of physiological changes, one of which includes metabolism.
The role of oestrogen alongside other hormones in metabolic homeostasis is complex. Oestrogen influences metabolism through several different pathways, including (1) fat distribution, (2) basal metabolic rate, (3) insulin sensitivity, (4) appetite regulation, and (5) energy expenditure.
An understanding of the relationship between oestrogen and metabolism (as well as the interplay between other hormones) is pivotal in making informed decisions regarding overall health and wellness in menopause and beyond.
What is the Link Between Oestrogen and Metabolism?
Hormones ultimately determine how the body stores fat. For example, fat distribution and weight gain are similar in boys and girls until they reach puberty. The hormone oestrogen is responsible for the typical female physique and fat distribution pattern, i.e. gynoid pattern (greater lower-body fat), where women tend to accumulate fat on their breasts, hips, buttocks, and thighs. In adolescence, the production of oestrogen by the ovaries leads to a higher body fat percentage in girls compared to boys of a similar age. Testosterone, on the other hand, results in a higher muscle-to-fat ratio and also gives boys and younger men a more masculine appearance.
During the reproductive years, higher levels of oestrogen result in additional fat stores, providing the body with sufficient energy reserves for any future pregnancies and/or lactation. During menopause, declining oestrogen levels lead to changes in body fat distribution, and postmenopausal women are more likely to gain weight in their abdominal region, i.e. android pattern (greater upper-body fat). Unfortunately, visceral fat is associated with health risks and can lead to long-term health issues.
Ageing, along with declining oestrogen and other hormonal changes that occur during menopause, also comes with a decrease in muscle mass. Muscle mass is directly linked to basal metabolic rate in that muscle requires more energy to maintain than fat. A decrease in muscle mass is therefore associated with a decrease in overall resting metabolism (i.e. the number of calories your body requires at rest).
Oestrogen is also linked to insulin regulation, i.e. how the cells in the body respond to the hormone insulin, which is responsible for blood sugar regulation. Loss of circulating oestrogen is associated with insulin resistance and changes in whole-body metabolism. Oestrogen, as well as other sex hormones, is also involved in appetite regulation and satiety. Oestrogen suppresses appetite, whilst progesterone and testosterone stimulate appetite. Finally, oestrogen also plays a role in energy expenditure, and higher levels of oestrogen are associated with a more efficient metabolism.
What is Metabolic Syndrome?
Metabolic syndrome is a lifestyle disease and the name given when five health conditions occur simultaneously, significantly increasing the risk for coronary heart disease, type 2 diabetes, and stroke. These conditions include: (1) high blood pressure, (2) high blood glucose, (3) low levels of blood high-density lipoprotein (HDL) or ‘good’ cholesterol, (4) elevated levels of blood triglycerides, and (5) large waist circumference, sometimes referred to as apple-shaped figure (waist to hip ratio of >0.85 and BMI >30).
Unfortunately, postmenopausal status carries a 60% increased risk for metabolic syndrome. This highlights the need for menopausal, and more specifically postmenopausal women, to make positive lifestyle changes to reduce their risk of developing metabolic syndrome.
Can HRT be Used to Manage Weight Gain in Menopause?
Studies have shown conflicting results regarding the impact of hormone replacement therapy (HRT) on weight management during menopause. There is no conclusive evidence to show that HRT prevents weight gain; however, there is some evidence to suggest that HRT (particularly oestrogen therapy) may prevent or minimise the redistribution of body fat. Furthermore, it may affect metabolism in some individuals and aid in weight loss or weight management. Other studies have shown no significant changes or even weight gain.
Overall, the results of HRT on weight management vary between individuals. Since weight gain during menopause cannot be attributed to a single variable, lifestyle modifications (i.e. eating a balanced diet, doing regular exercise, and managing stress) are crucial to managing weight during menopause, whether they are done in combination with HRT or not. It is best to speak to a healthcare professional about whether HRT treatment is appropriate by weighing up the benefits and risks regarding individual symptoms and circumstances.
Can Metabolism Be Reset in Menopause?
Whilst metabolism cannot be completely ‘reset’, adopting a healthy lifestyle and making positive changes to the daily routine can go a long way in terms of metabolic efficiency and mitigating some of the health issues associated with a slow metabolism. Focusing on a healthy balanced diet, regular exercise, stress management, and hormonal health are key.
A Healthy Diet
A healthy balanced diet should include nutrient-dense foods, such as whole grains, lean protein (chicken, fish, eggs, and Greek yoghurt), healthy fats (i.e. avocados, seeds, nuts, coconut oil, and olive oil), as well as a wide range of fruits and vegetables. It is also important to monitor portion sizes and manage caloric intake.
Processed foods, as well as foods and beverages high in sugar, should be avoided. A health professional or dietitian can further advise on which foods to eat, and which to avoid, and provide guidance on caloric requirements.
Unfortunately, menopause brings about hormonal changes that negatively impact metabolism via several mechanisms. These include alterations in fat distribution, reduction in muscle mass, as well as changes in insulin sensitivity and energy expenditure. These metabolic changes can ultimately lead to both short- and long-term health problems.
The good news is that an understanding and awareness of these changes should empower individuals to make proactive choices. Lifestyle factors to limit these metabolic changes include staying active, eating well, reducing stress levels, and seeking professional support and guidance during this transformative phase of life.