It doesn't matter how hard we fight it, middle age just seems to bring out the bulge.

On average, both men and women will gain between 8 – 16 kilograms between the ages of 35 and 55.  ‘Middle-age spread’ isn’t an urban myth at all.

This weight gain is largely due to hormonal imbalance, specifically too little progesterone and too much oestrogen. And the problem with too much oestrogen is that the hormone acts like a fat magnet, increasing the waistline – something many of us are constantly battling.

In a hormonally healthy person, the balance between the three sex hormones - oestrogen, progesterone and testosterone – is finely tuned. As we age that balance changes.

As a woman reaches her mid-30s, her levels of progesterone - which is produced in the ovaries and is essential for fertility - starts to decline. In fact, it declines 120% faster than oestrogen does and also much earlier; at a time when a women’s oestrogen levels are still youthful.

The result is ‘oestrogen dominance'. (In men, there is a similar drop in progesterone. When men reach their 40s, their levels of progesterone also decline. Again, the result is that oestrogen becomes more dominant)

The problem is compounded by the raised levels of oestrogen now found in our food, water and environment. So-called xeno-oestrogens (chemicals found in pesticides, plastics and other materials) mimic the effect of oestrogen and are fat-soluble, so store themselves in the body.

Our bodies’ own fatty tissue also produces oestrogen which in turn makes the body 'better' at storing fat, while at the same time, inhibiting our ability to effectively use fat stores for energy.

It’s a vicious circle because it means we put on extra weight around our middle that’s hard to move even with exercise or calorie reduction!

And ‘oestrogen dominance’ has other effects as well as increasing fat around the tummy. In women, symptoms range from headaches to incontinence; in men, symptoms include depression and reduced libido.

The good news is – you can do something about oestrogen dominance by making small lifestyle changes. Read ‘Fighting fat with food’ and ‘Stay young with exercise’ to find out how.