Ancient discipline: Joseph Shaw looks at fasting for Catholics

Ancient discipline

Joseph Shaw looks at fasting for Catholics

Intermittent fasting is the diet trend of the moment. That is not in itself a recommendation: the world of nutrition has been plagued by mutually contradictory theories and passing fads for decades, some ineffective, some not very healthy, and some lucrative to their promoters. I’m no expert on nutrition, so while I’ll try to explain the theory as presented in two books, I can’t really assess its claims: readers must use their own judgement. The reason I’m bringing it to the attention of Mass of Ages readers derives from two aspects of this approach to diet which set it apart from others: its relationship with the ancient Catholic discipline of fasting, and its relationship with ordinary culinary culture.

To understand these two issues, I need to explain the intermittent fasting theory. Its major populariser, Jason Fung, gives in his book a very interesting account of the modern history of nutrition, the science of blood-sugar regulation, diabetes, and why things have gone so wrong: which clearly, they have, particularly in the USA and the UK, where the rates of obesity (and diabetes) are so high. But a helpful way of introducing the fundamental point would be to compare two fasts: the Minnesota Starvation Experiment of 1944-5, and Angus Barbieri of Tayport, Scotland, in 1965-6.

The Minnesota Starvation Experiment isolated the subjects, 36 conscientious objectors, and progressively reduced their food intake to make them lose an average of 25% of their total body weight, over 24 weeks, before allowing them to recover. The idea was to study the effects of malnourishment, which was a major problem in war-torn Europe. What they discovered is that the human body has an amazing capacity to cut its energy usage when it has to: it was surprisingly difficult to get the men to lose the weight the experimenters had planned. In the meantime, the wretched subjects felt the cold acutely, lacked strength in standardised activities, and became obsessed with food: thinking about it, dreaming about it, and in some cases stealing it, and being thrown out of the experiment as a result.

Contrasting

Anyone who has been on a calory-controlled diet will know exactly how they felt. However, Angus Barbieri presents a contrasting case. He was seriously overweight, and, under medical supervision and taking vitamins and other supplements, ate nothing at all for 382 days. That’s right, for more than a year, he lived off his fat. He lost 276 lb, and said he felt fine. He put on a bit of weight after returning to a normal diet, but he didn’t go back to being obese.

Now, no-one is recommending mimicking Barbieri’s feat. But given the results of the Minnesota experiment, which corresponds to so much common experience, how on earth did he do it? Why was his fast so different from theirs? For his experience can also be paralleled. Many ascetics, of various religious traditions, have fasted for long periods, apparently without causing their bodies to shut down in the way the Minnesota subjects’ did. One might think that ascetics have incredible selfcontrol that ordinary people lack, but actually fasting, on a scale difficult to imagine for us today, used to be a universal practice. It was only a couple of generations ago that Catholics had to fast every day in Lent, leaving aside Sundays. It wasn’t superhuman; people just got used to it. But how?

Dr Fung and his follower Jay Richards offer an explanation. My very non-expert attempt to understand it goes like this. The body has two modes of providing energy for our cells, depending on what food is available. Carbohydrates and sugars are very easily converted into energy, and if they are plentiful in your diet that is what happens. If you consume more than you need, the excess is converted into fat for storage, as we all know. Burning fat, on the other hand, is harder work: it involves a more complicated process and uses more energy. (Protein comes in between the two, and of course most food on one’s plate includes elements of all food groups.) The body won’t go to the trouble of burning fat if it doesn’t need to.

Western diet

Accordingly, the body of someone who habitually eats the amount of sugar and carbohydrate typical of the modern Western diet, uses the sugars and carbohydrates for preference, and if they are restricted, it asks for more: hence you can get cravings for sweet things. At the same time, if there is a serious shortage the body tends to close down non-essential functions, and you can feel cold and weak.

On the other hand, if your diet is more fat-oriented, your body is used to burning fats, and can shift more easily from burning fat which you have just eaten, to burning fat that you have stored away. Fung suggests that for a couple of weeks before you start fasting you should adapt your diet so that you take in half your calories from fats. With this conditioning in place, if there is then a shortage, the body much more readily turns to the fat which has been stored away, instead of demanding sugars and carbohydrates through cravings, and simultaneously cutting down the body’s metabolism.

In the Minnesota experiment the subjects were fed with carbohydrates, and this made their lives much more miserable than necessary. With Barbieri, despite his previously normal (or poor) diet, a complete cessation of eating for long enough stimulates the body to move into fat-burning mode. Having made that transition, Barbieri wasn’t plagued by cravings and weakness.

I really have no idea if this theory corresponds to scientific reality. I confess, however, that over the time of the first lockdown, I tried it, and, well, it worked for me. I hadn’t previously found fasting at all easy, but the preparation recommended by the intermittent fasting theory makes it much, much easier. Yes, I got hungry, but hunger is not continuous: it comes and goes, and Fung and Jay suggest having a hot drink or distracting oneself for a bit. I did, in fact, feel the cold more than usual, and it helped that I wasn’t going out much or doing hard physical labour. I was amazed, however, that I didn’t go mad with food-cravings, even while fasting for a whole day, or two, or even three, at a time.

More technical

Of the two books, Fung’s is more technical; for the practical issues of fasting, I found Jay’s (which has a foreword by Fung) easier to understand. While some of Jay’s digressions are a little silly, he does make a serious attempt to put intermittent fasting into a Christian and Catholic context. With this approach, fasting can be a penance, a sacrifice, something we can do out of devotion, as well as for our health, but it’s not a torture, a superhuman act of self-control, or something which sets us up to fail.

Another aspect of the diet which is worthy of note is this. Many diets demand a life-time of ‘funny eating’: some exclude whole food groups; some exclude a bewildering variety of individual items. Going to a restaurant can be complicated; dining with friends, a nightmare. It’s not as if we could all adapt our culinary culture to some new scientific discovery: there can be as many faddish diets as chairs around the table at a dinner-party, and some people hop rapidly from one demanding and peculiar diet to another in a never-ending series.

When an Atkins dieter says he can’t have bread, potatoes, or pasta, he is excluding himself from fundamental components of European cuisine. Low-fat diets make many of the best dishes of many culinary traditions not just difficult to make but unrewarding, because of the role fats play in the cooking process, and in making us feel satisfied. Steamed vegetables and poached white fish is not the same as duck confit or roast potatoes.

Dietary fashions

Food and cooking are fundamental elements of human culture. If that is obvious, one must recognise that the constantly-changing dietary fashions of the past fifty years have done huge damage to it. They have contributed to the disappearance of culinary traditions, and to the ties between generations constituted by the passing on of recipes. Nearly all nutritionists would agree that it is best to prepare food from scratch, at home, but their food-fads have made doing this absurdly complicated, just at the moment when many young adults lack the confidence even to boil themselves an egg.

Intermittent fasting allows us to eat, like our Catholic predecessors, with regard for taste and satisfaction, and above all normally, in relation to our particular food culture. No authentic culinary tradition includes the hideous products of the modern food industry, highly processed and stuffed with sugar and salt. At the same time, we should mix feasting with fasting: celebration and thanksgiving with penance and petition.

The Obesity Code: the bestselling guide to unlocking the secrets of weight loss by Jason Fung (2016)

Eat, Fast, Feast: Heal Your Body While Feeding Your Soul-A Christian Guide to Fasting by Jay W. Richards (2020)