It’s the diet of the moment. If you frequent trendy cafes, you may have overheard people refusing muffins or opting to take their coffee black because they’re “on a fast day”. The ‘fast diet’, the ‘5:2 diet’, the ‘feast and famine diet’ – whatever you want to call it, seems to be on everybody’s lips. But what exactly is it? And is it any good for people living with inflammatory bowel disease (IBD), or should it be avoided altogether?
The basic principle of the diet is not necessarily to change what you eat, but rather when and how much you eat. On two non-consecutive days per week, you cut your calories to approximately a quarter of your usual daily energy intake – that’s 600 calories for men and 500 calories for women. The rest of the week you eat fairly normally, albeit a bit healthier.
According to fans of this way of eating, restricting calories on two days per week results in a kind of ‘reset’ of certain hormones relating to insulin and metabolism and results in dieters reducing their overall weekly calorie intake by approximately one quarter. Followers of the diet claim numerous benefits as a result of their intermittent calorie restriction – including weight loss, better blood sugar levels, improved cognitive function and slowing down the effects/onset of Alzheimer’s disease. It’s important to note though that a lot of these benefits have been inferred based on animal studies into fasting and anecdotal evidence. Much more research needs to be done to support these claims for humans.
So is it any good for those with IBD? Unlike many other diets of the moment, the fast diet doesn’t actually outlaw certain foods or advocate others. This gives dieters the freedom to choose foods that suit their tastes and digestive systems. It’s more a changed way of eating, than a diet per se. For this reason, people with IBD may be able to follow this way of eating with minimal disruption to their regular routine.
Of course, when your calorie count is lowered, it’s a pretty good incentive to steer clear of high-calorie packaged food (read: notorious IBD trigger foods) and instead spend your energy budget on nutritious low calorie options like fresh vegetables and eggs. Things like sugar and alcohol (common trigger foods for IBD sufferers) are pretty much off the table on a fast day as they’re calorie-dense and not very filling. Soothing herbal teas on the other hand (great salves for upset digestive systems) are absolutely welcome.
While some claim that fasting affects the immune system and helps reduce auto-immune conditions such as Crohn’s, these are anecdotal at best and no official research supports such claims as yet. There are studies underway looking at intermittent fasting (though not the 5:2 diet specifically) and Crohn’s disease in the hope that this approach to diet may lead to new treatments for Crohn’s sufferers.
While you can choose IBD-friendly foods as part of this diet, the frequency of eating or the reduced calorie intake may have an effect on your Crohn’s or ulcerative colitis.
especially important to consider if you have issues with malabsorption, as calorie restriction might not be the best idea, compounding already poor nutrient uptake.
Before experimenting with any new diets or changing the way you eat, it’s important to discuss everything with your doctor, especially if you suffer from IBD, other chronic health conditions or take medication.