Skip to main content

How to deal with unhealthy habits

Many believe that people who eat unhealthily simply lack willpower and that lifestyle-related illnesses show sufferers up as having a ‘weak character’.

But current research findings do not support these widely-held prejudices. It has been shown that eating behaviours are often automatic, in the sense that they are triggered by tiny signals in our immediate environment.1 For this reason, you will find it worth-while to try to be alert to any deep-rooted habits that influence what you do. It is much more useful than blaming yourself for being weak. Once you recognise the triggers, it becomes easier to change your response and prepare counter-moves so you don’t give in to them so easily.

Let’s have a look at some of the research reports on these subjects.

Portion size matters

The size of the portion on the plate is an important cue to eating behaviour. Regardless of how much the portion weighs and what the ingredients are, and regardless of how hungry people are at the start of the meal, they always eat more when served the larger portions.

In one study, restaurant customers would get either a standard pasta dish or, on other days, a 50% larger serving. Customers given the larger portion ate on average 43%, or 159 kilocalories, more than those who got the standard plateful.2 The excess calorie intake was relatively small but one that will have a big effect if the behaviour is repeated day after day. Researchers at Harvard University have shown that an increase in daily intake of as little as 100 calories can cause severe overweight in the long term.3

Portion size seems to matter even more than the taste of what we eat. A study was carried out on popcorn consumption in a cinema: the movie goers were either given freshly made popcorn or stale popcorn that was a fortnight old. It was served in either a normal or twice-normal size container. Many of the people who were given the old product in a big box complained about the taste but, even so, they actually ate more of it than those who had been given fresh popcorn in a normal-sized box!4

The role of ease

The effort required to eat is also a factor. People with a bowl of candy close at hand on their desk ate five times more during their time at work than those who kept the candy on a shelf some 2 metres away. Consumption was even larger if the candy was temptingly visible in transparent bowls rather than kept in closed boxes.5

‘Priming’ affects your behaviour

The way you behave can be affected by subtle signals that you are not actually aware of. This phenomenon is known as ’priming’. In one study, subjects with access to fizzy drinks were shown a picture of either a jolly or an angry face: they drank more if presented with the jolly face.6

Another study showed that customers bought wines from either France or Germany depending on whether French or German music was played. When interviewed afterwards, the customers had no idea of why they had bought that particular country’s product.7

Shop managers are often experts on the use of cues aimed at nudging us towards buying specific goods (not always the healthiest). Music, images and placement inside the shop are modified. To place goods on large shelves or at eye-level or near the tills are all classic ways of priming our purchasing behaviour. Since shop managers can act so knowingly, it won’t harm us to be a little wary and think before we pick something, maybe on impulse, from these prominent places.

How to become aware of your habits

Many are unaware of how automatic their eating behaviours are.1 The people given the larger serving in the portion-size study did not believe that they had eaten more than the standard portion customers. It is characteristic of automatic eating that it is more of an effort to interrupt what you are doing than to carry on – one doesn’t stop until the candy has run out or the film has ended.

Observations of this kind of course do not prove that we are helpless and can’t change how and when and what we eat. On the contrary, we can change but only if we are aware of our habits.1

It can depend on being more alert to external signals such as priming and placement in shops. Or we could focus on altering the signals that we can modify ourselves: replace the large plates with smaller ones, move candy well out of the way (or stop buying it) and instead put healthier foods on display.

We cannot possibly make considered decisions about everything we encounter in our daily lives. But by being aware and planning what our immediate surrounding are like, we can help ourselves well on the way to healthier habits.

How you aware are of your habits and how can you deal with the less healthy ones?


  1. Cohen DA, Farley TA. Eating as an automatic behavior. Prev Chronic Dis 2008;5(1).

  2. Diliberti N, et al. Increased portion size leads to increased energy intake in a restaurant meal. Obes Res 2004;12(3):562-8.

  3. Cutler DM, et al. Why have Americans become more obese? Cambridge (MA): National Bureau of Economic Research; 2003. p. 9446.

  4. Wansink B, et al. Bad popcorn in big buckets: portion size can influence intake as much as taste. J Nutr Educ Behav 2005;37(5):242-5.

  5. Painter JE, et al. How visibility and convenience influence candy consumption. Appetite 2002;38(3):237-8.

  6. Berridge KC et al. What is an unconscious emotion? (The case for unconscious “liking”). Cognition and Emotion 2003;17(2):181-211.

  7. North AC, et al. In-store music affects product choice. Nature 1997;390(6656):132.

This block is broken or missing. You may be missing content or you might need to enable the original module.