Will power, or self-control, is like a muscle that uses up energy. You might start the day with a strong ‘self control’ muscle – but by the afternoon its strength is all used up and you cave in. Sound familiar?
One of the earliest studies, carried out at California’s Stanford University in 1972, involved more than 600 children aged between four and six who were given a sweet treat. The children could eat the treat, but if they waited 15 minutes without eating it, they would be rewarded with two treats. Some children covered their eyes or turned around so that they couldn’t see the treat, others distracted themselves. A minority ate the treat immediately, and one-third deferred gratification long enough to get the second treat. But of the majority that couldn’t resist, most gave in towards the end of the 15 minutes, not at the start.
It’s hard work being self-controlled, and the longer you do it the harder it gets. A 2010 meta-analysis of 83 studies shows that after exerting self-control, people perform worse on the next self-control task. However, if a person is given some glucose in between, they are more likely to succeed at a second self-control task.
Resisting temptation actually uses up blood sugar in much the same way that exercising a muscle does. What will power research also clearly shows is that any exertion of self-control, for example a hard day at work, effects any act of self-control, for example sticking to your diet. This is probably why many people give in to temptation later in the day. Some studies suggest that the average person spends between two to three hours each day resisting temptation, hence exerting self-control. That’s a lot of energy used up by your will power muscles.
So how does this help you? First of all, this emphasises why it is so important to keep your blood sugar level even. My low-GL diet recommends three meals and two snacks, especially an afternoon snack. If you skip this, your blood sugar level – and your will power – is likely to be low. Also, the less temptation there is around you, the better. For example, empty your kitchen of foods you want to avoid. Take your lunch and snacks to work, rather then passing multiple temptations as you queue to buy. Or meet your friend for a walk round the park rather than at Starbucks.
The research also shows that getting some rest and relaxation also helps to restore will power. This suggests that having some chill-out time, or even a siesta in the afternoon, followed by a low-GL snack (eg an apple and some almonds, two oatcakes with cottage cheese, a carrot and some hummus), helps reload your willpower.