The principle of “everything in moderation” is supposed to be an excellent approach for leading a healthy life. But is it really all that it's cracked up to be? Or are we better off adopting an all-or-nothing approach to eating, exercising, and living our lives in general?

The idea that “everything in moderation” is the key to a long, healthy and happy life is a very, very old one. It goes back at least two and a half thousand years to the writings of Hippocrates, the founder of modern medicine as we know it. Hippocrates saw health as a matter of balancing the body's different systems. In order to achieve balance, he argued, we need to eat, drink, sleep and play – all in moderation.

The idea of moderation has persisted. It's easy to see why. When experts' opinions on what is and isn't good for us seem to change every week and we are left bewildered, overwhelmed and unsure what to believe, “everything in moderation” seems like a safe line to tread. How can we go wrong?

Setting aside for one moment the obvious caveat that some things just aren't good for us, not even in moderation (smoking is an obvious one), the big problem with moderation is that human beings are generally rubbish at it.

Think about our evolutionary origins for a moment. We evolved as a hunter-gatherer species. That means that food was either pretty scarce or suddenly abundant. If you found a tree laden with ripe fruit, the thing to do was to gorge yourself on it – because tomorrow, who knows? If you got lucky hunting, the same principle applied. Such periods of plenty would have been interspersed with longer stretches of relative scarcity. The same applied to physical exertion – you were either running hell for leather in your role as prey or predator, or you were resting and recuperating in your cave. Chances are that we evolved to function in an all-or-nothing way – not in moderation.

It seems that we are starting to become wise to this idea. Here are some examples.

An all-or-nothing approach to food

There are two diets that are immensely popular at the moment and eschew the principle of moderation: The primal/paleo diet (and some versions of the low-carb approach) and the 5:2 diet. In a nutshell, the former involves avoiding processed foods, particularly refined sugar and refined grain whereas the latter involves eating freely 5 days a week and having 2 “fasting” days. Both diets claim some pretty impressive results so far, both in terms of weight loss and overall health improvement.

It's interesting to observe that both of these approaches work on an all-or-nothing principle. Why does moderation, applied to our diets, fail so often?

1.       Some foods simply aren't good for us, not even in moderation. Refined sugar, grains and oils fall into this category, as do alcohol and all sugary soft drinks. They might not do us an enormous amount of harm in moderation, but they're not actively beneficial to our health.

2.       We're generally terrible at judging portion size, which makes it very difficult to have just a small treat. We're not helped by the ubiquitous trend in the food industry towards supersizing everything, from chocolate bars (cleverly marketed as being intended for sharing) to soft drinks.

3.       Many people just cannot do moderation very well. As Samuel Pepys put it, “Abstinence is as easy to me as temperance would be difficult.” In other words, it's easier to decide that you're not going to eat any biscuits than it is to eat one biscuit (and end up eating the whole pack).

4.       Boredom. Eating sensibly and with restraint, day in and day out, is actually a lot less interesting than being super healthy 80% of the time and really indulging yourself for the other 20%.

An all-or-nothing approach to exercise

The world of fitness and exercise is seeing a similar trend towards an all-or-nothing approach as the world of dieting. One particularly popular approach is High Intensity Training (HIT) which is all about going hell-for-leather for very brief periods of time, and resting in between. It seems to be just as good for improving strength and stamina as traditional cardiovascular and muscle training regimes. So why does exercise in moderation often fail?

1.       It's boring. We all know that a half-hour walk every day would do us a world of good, but it's hard to find the motivation. It's much more inspiring to really push yourself (and get good rest when you're not pushing yourself).

2.       Your body habituates to gentle, regular exercise, whereas brief bursts of more intense exercise don't have this effect. This means that an all-or-nothing approach can be much more effective than a regime of moderate exercise.

“Everything in moderation, including moderation.” (Oscar Wilde)

There is a lot to be said for an all-or-nothing approach to diet and exercise, and perhaps to life in general, and it's important to recognise that “everything in moderation” is not necessarily the healthiest approach to take. But it would be foolish to suggest that there is no place for moderation at all. Perhaps, as Oscar Wilde suggested, we need to apply the principle of moderation to moderation itself, leaving some room in life for total abstinence as well as wild excess. Our lives will certainly be more interesting for it, and probably healthier.

What works for you? All-or-nothing or moderation? Are you a natural “abstainer” or a “moderator”?