Intermittent Fasting - fad or not?

Also known as the 5:2, alternate day fasting, or the fast diet. These are all the names of a popular diet concept that involves restricting intake to 500 calories for women or 600 calories per day for men. You do this for 2 days a week and eat normally on the other 5 days.

By restricting your energy intake to 2 days a week, you are likely to lose weight as long as you don’t over eat on the other 5 days of the week. Some recent studies have also shown a reduction in HbA1c in Type 2 diabetics. However, those on sulfonylurea’s or insulin will need to engage with their GP or practice nurse to review their medications before starting this diet to prevent hypo’s on fasting days.

By restricting calories on fasting days, you are also likely to miss out on some essential nutrients, so it is important to aim to include a variety of foods on your non-fasting days too (fruits and vegetables, meat and alternatives, dairy, grains and starches and fats and oils).

There are also lots of unknowns with intermittent fasting – with most trials only looking at weight loss, energy and nutrient intake up until 12 months. We do not know the long-term effects on the body. The weight loss and improvements shown in HbA1c are similar to those following a simple nutritious diet – so focusing on meeting the ministry of health eating guidelines and reducing your fat, sugar and salt intake may be just as effective.

If you would like to know more about whether intermittent fasting is right for you, or to discuss other ways to improve your health please book a session with one of our three Dietitians.