By Dr. Colin Michie FRCPCH
Fasting during celebrations and holidays? No way! But planning how to eat later in 2026, with both feasts and fasts, may be less trouble than you imagine. There is growing, powerful evidence that intermittent fasting is really great news for your heath, not just your waistline.
Rhythms, religions, the calendars of many lands include fasting. It is a well-known way to create a different state of consciousness, awareness or self-enlightenment. We now know that fasting helps nerve cells to grow, form synapses and repair. It reverses signs of brain ageing. By managing when and how you eat, you can benefit your metabolism, gut health, microbiome and immune defences in practical ways.
Hormones and messengers communicate with the gut, brain and other organs to find the most convenient body fuels. In a normal day, glucose is probably the most traded fuel, usually sourced from the gut from a recent meal, or stores in liver and muscles. After about 12-36 hours of fasting, fuel is pulled in by switching to fat stores. These (as we all know!) are found in and around the abdomen, muscles, under the skin and in the bone marrow.
Breakdown of fat releases small molecules, ketone bodies or ketones. The most common of these is β-hydroxybutyrate; others include acetone and acetoacetate. All organs, including the heart and kidneys can use ketones as energy sources. Acetone can be smelled on the breath when its levels are high. (This happens after fasting or periods of hard physical activity – it has a fruity or flowery smell.)
Ketone bodies are not just fuels, they are “super-fuels”. They have profound effects on many processes in our bodies – not only weight-loss. They improve immunity and protective systems. They reduce inflammatory responses. Beneficial changes to the gut and its microbiome within it develop after several months of intermittent fasting. Insulin resistance falls too, driving metabolic recovery. Kidney function in diabetics may improve. Damage in and around joints in arthritis can become milder. Multiplication and spread of cancer cells can be slowed, as many malignant cells preferentially use glucose as fuel. Trials are taking place to included ketones to current chemotherapy routines.
Intermittent fasting works as a drug-free strategy. It slows some effects of time on the brain, possibly preventing neurodegeneration, such as dementias, Parkinson’s disease and Alzheimer’s disease. For over a century, ketones have been used to reduce seizures in some individuals with epilepsy. Ketones support the growth and repair processes of nerve networks. They increase connections or synapses between them. Improved memory and learning and reducing depression have been observed in clinical studies. These support those ancient observations that thought processes and perceptions begin to change when we fast.
This type of fasting has been classified by some as a “moderate stress”. In this way, it resembles physical exercise, or exposure to cold as in wild swimming. These are all referred to as hormesis, or beneficial adaptations. Exploring how hormesis works is yielding new approaches to many novel approaches to improving our future health. Intermittent fasting can be planned. The 5/2 style recommends taking a normal diet for five days each week, but for two non-consecutive days limiting calorie intake to 500-600 calories.
An alternative approach, the daily 16/8, directs no food for 16 hours each day, taking perhaps a lunch and dinner in the remaining eight hours. Most practising these types of routines for two or three months find them easier than just restricting their calorie intakes, with fewer hunger sensations. Reduction in weight of over half a stone, along with improvement in general health is reported.
Changing what and when you eat is never easy; old habits and inner rules need to be locked away. Sensations of hunger need to be faced down, particularly in the food-rich environments of parts of our islands. Several tools, tricks and preparations help. Hydration and drinking water are important during fasting: Teas or black coffees without sugar – no alcohol – are permitted! Chewing gum helps some.
Plan menus, too, so you can enjoy meals; and work around your social life, your calendar, your fast for several months: mindful eating. Now is an opportunity to eat more plants, whole grains, less sugar, more fibre. Working with a fasting buddy, or buddies, or perhaps your physician may support your determination and manage the many temptations to snack, to break that routine. You might improve your pattern of physical exercise, too: muscle activities support the benefits of ketones.
Benefits from intermittent fasting are gaining increasing support. This hormetic stress brings together the magic of the hermit’s cell, the proof of clinical trials, a promise of healthy weight loss. Consider intermittent fasting to prepare you for the excitements, challenges, the great journeys of 2026.
Useful resources: nhs.uk/better-health/lose-weight ~ cdc.gov/healthy-weight-growth/losing-weight/keeping-it-off.html
Dr. Colin Michie specializes in paediatrics, nutrition, and immunology. Michie has worked in the UK, southern Africa and Gaza as a paediatrician and educator and was the associate Academic Dean for the American University of the Caribbean Medical School in Sint Maarten a few years ago.
