Andropause, sometimes misleadingly dubbed male menopause or ‘mano-pause’, is an age-related condition linked to the natural decline of testosterone in midlife. It can cause an array of symptoms typically affecting energy levels, muscle mass, sex drive, and mood.
Although it is normal and natural for testosterone to decline gradually after the age of 40, lifestyle and behavioural factors can exacerbate its decline and testosterone deficiency can make you more prone to putting on weight and, unfairly, even if you are regularly exercising and eating well, you can still be potentially at risk of piling on the pounds. The question is why?
Low testosterone
Testosterone levels in men fall gradually by around 1%-2% a year from around the late 30s onwards – with up to half the levels of bioavailable testosterone decreased by the time they reach their 50s.1 Why this is significant in terms of your weight is that testosterone plays a key role in both weight management and muscle building. Lowered testosterone can also cause your body to store excess fat around your gut. Fat stored around the abdomen contains higher levels of an enzyme responsible for converting testosterone into oestrogen, which can then suppress testosterone levels further.2 To put it simply, low testosterone makes it more likely you will gain weight and the heavier you are the less testosterone your body produces.3 This hormonal decline can lead to a range of seemingly diverse, but actually connected, physiological changes.
Metabolism changes
Your metabolism – the rate at which your body breaks down food and turns it into energy – slows down with age, as do your testosterone levels. Testosterone plays a supporting role in metabolism function in that it helps you to burn fat and calories plus helps maintain muscle mass.
Loss of muscle mass and strength
Declining testosterone can lead to a loss of muscle mass and strength and not having enough of it can hinder muscle growth and maintenance. Muscles are known to burn more calories than fat so trying to nurture and maintain more muscle, with regular exercise and a balanced diet, should help keep your weight down.
Cortisol
Cortisol is an essential hormone which helps your body to manage stress. However, if you are going through particularly stressful times and producing high levels of it long-term it can cause negative side effects. Not least because cortisol and testosterone interact in a kind of see-saw fashion – so when one is low, the other goes high. Why this is a problem is that overproduction of cortisol is known to push up your blood sugar levels and evidence suggests this can lead to overeating and contribute to weight gain, particularly around the belly. It also affects lean muscle mass by breaking down muscle tissue which then slows down metabolism and how many calories your body burns. Consuming too much sugar, caffeine, alcohol and/or refined carbohydrates (such as white processed bread, white pasta, white rice or cakes, biscuits and pastries) are also known to cause rapid spikes in blood sugar (which causes your body to produce insulin to help bring it down again) and a related increase in cortisol levels.
Insulin resistance
Low testosterone levels are linked to insulin resistance, where the body can’t regulate blood sugar levels and if levels get thrown off balance your body starts to store that excess sugar as fat. High cortisol can also potentially lead to insulin resistance which, in turn, can make you more prone to weight gain. Recent studies show that diets high in refined carbohydrates – which cause blood sugar to spike quickly - put you at increased risk of insulin resistance, type 2 diabetes and heart disease.4
Appetite controlling hormones
Having low testosterone levels can upset the balance between leptin and ghrelin, two hormones which work together to signal when you are hungry and/or full. Ghrelin (known as the hunger hormone) causes you to feel hungry and fuels your appetite whilst leptin (known as the satiety hormone) signals to your brain you have eaten enough. If these hormones are disrupted you can find it harder to know when you have eaten enough and if you are actually still hungry.
An ‘inefficient’ gut
Research in this area is relatively new but what there is suggests that gut health and testosterone production are connected. Men with low testosterone often have less balanced and varied gut microbiota compared to those with more healthy testosterone levels. A healthy gut microbiome is important for weight loss as it can affect metabolism, appetite and digestion. Some studies (on animals)5 have also shown that different bacteria in the gut can affect how much of the appetite-affecting hormones leptin and ghrelin are produced and whether you are likely to feel hungry or full.
For information on how to prevent or reverse weight gain read 'How to avoid putting on weight during andropause' here.
References
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2544367/
- https://pubmed.ncbi.nlm.nih.gov/12198740/
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3955331/
- https://www.nhs.uk/conditions/metabolic-syndrome/
- https://pubmed.ncbi.nlm.nih.gov/27616451/
