Fasting – the lasting fad

The good and the bad

The benefits of fasting have been reported widely with studies in humans seeing effects on blood sugar levels, weight loss, and markers for heart disease. Many followers of the fast diet say that it’s easier to stick to than a conventional low calorie diet and is motivating due to the fast weight loss results. On the flip-side however, some followers of the 5:2 diet have reported low energy, headaches, gastric disturbances and even changes in menstrual cycle.

The easier option

For those who find the idea of just 500 calories twice a week too much of challenge, the latest research may appeal. A study published last week in the journal Cell Metabolism reports that ‘fasting’ just once a month by cutting back in calorie intake to around 34 to 54 percent of normal intake (for five consecutive days) can decrease risk factors and biomarkers for aging, diabetes, cardiovascular disease and cancer with no major side effects. The study found that by cutting down on calories dramatically for five days in a row, decreased amounts of the hormone IGF-I, which is a promoter of aging and has been linked to cancer susceptibility.

The main researcher involved in the study however does warn that fasting isn’t suitable for everyone and says that the health consequences can be severe if it’s not done correctly. Remember that fasting is never advisable for anyone with a medical condition, pregnant or breastfeeding women or anyone with a Body Mass Index of under 18.

Written by Ruth Tongue

(MSc Nutrition)

Brandhorst, S et al. A Periodic Diet that Mimics Fasting Promotes Multi-System Regeneration, Enhanced Cognitive Performance, and Healthspan. Cell Metabolism, 2015; DOI: