This could be why you're fat - 7

STUBBORN FAT AROUND THE MIDDLE

COULD BE: Polycystic ovary syndrome.

This is a hormone-related condition that affects 5 to 10 per cent of women of childbearing age.

It can appear at any time after puberty and usually eases off by the menopause.

The fat generally appears around the middle — on the tummy, chest and back.

Other tell-tale signs include irregular or absent periods, acne, excess hair on the face and thighs. Most of the symptoms are triggered by too much testosterone and other male hormones.

Sufferers very often also have a condition called insulin resistance, which makes them gain weight very easily — only to find losing it very difficult, too. If you are insulin-resistant, the cells react sluggishly to the hormone insulin — which mops up excess blood sugar.

The blood sugar is instead sent to your liver and converted into body fat, which is then deposited usually around the middle of the body (so it is close to the major organs to be instantly accessed if needed)

WHO'S AT RISK? Women of childbearing age. While no one knows what causes it, there is thought to be a genetic link.

WEIGHT-LOSS SOLUTION: If your weight gain comes with irregular or absent periods, acne, excess hair on the face and thinning hair, ask your GP for a blood test; you may also be offered an ultrasound scan of your ovaries.

There is no cure for the condition, but medical treatments (such as the Pill and the diabetes drug, metformin) can ease symptoms.

Switching to a low GI diet can help to control excess insulin (and therefore reduce weight gain and many other symptoms).