Does it work for everyone?

There are very distinct benefits to intermittent fasting (IF) for those who do well on it, including increased energy and improved cognitive ability, memory and insulin sensitivity. The aim is to cut down the amount of food you eat, but carry on living normally without affecting your metabolic rate, by choosing a ‘window’ of time – ranging from eight to 16 hours a day or once a week – during which you don’t eat.

The problem is, many women who try IF find they suffer from anxiety, insomnia, irregular or total cessation of periods, or other hormonal problems. When a woman’s calorific intake drops below a certain level, her energy generally declines, her stress levels rise and her hormones are adversely affected. Some men experience this too, but it usually takes much longer to manifest. It’s also been found that reducing fat and calorific intake can affect fertility in women and even lead to early menopause.

12 | LOSE IT!

I have seen some women lose weight on IF, but once they resume eating even a very low-carb diet, they usually put on part – if not all – of the weight lost, often with interest.

Fasting too often or for too long at a time can slow metabolism, causing thyroid and general endocrine mayhem in many women. In both men and women, reducing food intake and meal frequency, restricting calories and exercising excessively can lead to adrenal fatigue, which in itself creates a whole new set of problems that can only be overcome by following a strict protocol, and it will make losing weight even more difficult. The bottom line is, you should never fast if you have adrenal issues, or if you’re pregnant or on chronic medication.

HORMONES AND IF Three endocrine glands work together in the body to trigger hormone release. First, the hypothalamus releases gonadotropin-releasing hormone (GnRH), which prompts the pituitary gland to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH). LH and FSH then act on the gonads (ovaries or testes) to trigger oestrogen and progesterone production in women, and testosterone and sperm production in men. For women, in particular, GnRH needs to be precisely timed or their hormones will be disrupted.

No one is certain why women are so sensitive to IF, but it is suspected that a protein-like