A natural function of ageing for men is that their level of testosterone will fall, but what’s new is the degree in which it is happening. In the UK, one estimate has 35% of men over the age of 45 having a testosterone deficiency. So, if you’ve gained a bit of weight, and are disinterested in sex, this could be a reason for it…

Joining Seán to discuss is Dr. Jeff Foster, GP and author of ‘Optimal: Understanding Testosterone for Strength, Health and Wellness’.