Is the Fasting Diet safe?

Is the Fasting Diet safe?
Could fasting help you drop pounds - and inches?

Everyone seems to be on the fasting diet, thinking about it, or talking about it. Yep, there's a new diet in town, and apparently it works. But at what cost to your health, and is it sustainable?

SportsShoes in-house nutrition specialist gives her verdict...

The Fasting Diet: the theory

Calorie restriction on a number of days each week mimics our genetic roots, when we lived in a time of famine followed by fast.

Under these conditions, lower levels of insulin are secreted and this encourages the body to release glucose, stored as fat, to provide energy, and in doing so start the process of fat burning. This state also helps control chemicals in our body which are responsible for promoting disease and ageing, offering time of respite from normal digestive functions for the body to repair and heal, thereby suggesting that fasting offers health benefits beyond simple weight loss.

The Fasting Diet: the reality

Various levels of fasting are suggested, from multiple-day liquid-only fasts, to fasting alternate days, and most popular at the moment is a ‘5:2’ regime of five days during the week when you eat normally, and two non-consecutive days when you eat a limited number of calories restricted to around 25% of your normal daily requirements.

The Fasting Diet: is it sustainable?

Multiple-day fasting and alternate-day programmes are likely to be the hardest to maintain, and are therefore unsustainable for most individuals.

The 5:2 regime, however, appears to be more practical since it can fit around most normal schedules and you're therefore more likely to find yourself able to stick to it.

Feedback from users suggests that concerns about hunger, feeling faint and poor concentration are largely unfounded, and that the knowledge you can eat normally the following day makes it achievable.

Statistics appear to indicate not only weight loss, but also an improvement in vital health markers such as LDL (bad) cholesterol, reduction in blood pressure and chronic inflammation, as well as an improvement in mood and mental clarity.

The diet has been promoted and endorsed by a GP and, unlike most diets, appears to have a following amongst the medical community.

The Fasting Diet: the verdict

The 5:2 diet is still in its infancy and there are no studies available yet as to its long term success. However, early evidence seems to suggest that in some individuals, a regime of intermittent fasting can work, although the pattern should be adapted to the individual. Some challenges with the diet still need to be considered:

  • Breaking normal eating habits can be difficult for those who are used to 3+ meals a day and snacks in between.
  • Avoiding a mentality of deprivation and reward with calorie restriction on some days followed by bingeing unhealthily on others is also important.
  • Whilst it advocates ‘normal’ eating when not fasting, it is important to continue to maintain a balance of food groups and not just rely on processed foods, saturated fats and alcohol.
  • Trying to follow the programme whilst in training for a long distance or endurance event could be problematic and should be considered carefully with professional advice. For normal shorter training sessions, however, the body is thought to adapt and simply find energy from fat stores.

Note: Diets should never be undertaken without seeking medical advice to ensure the programme is safe and suitable for the individual.