In these days of relative plenty, hunger is not the main trigger to eat. Most of us don't really know what hunger feels like anymore. 

Vision - what we see - is one part of the complex pattern of factors influencing the amount of food we eat. So if we are looking through the kitchen cupboards and spot a bag of crisps, we are likely to eat them, even if we have just eaten a full meal. If there are no crisps to be seen, we manage to do without.

Many of us eat because we see something nice. We get hungry watching the food programmes on the telly, or reading a magazine, or wandering through the aisles in the supermarket. All these things make us think about food and eating. So our eyes are more likely to tempt us to eat than the signals coming from our body.

Yvonne Linné, Britta Barkeling, Stephan Rössner and Pål Rooth of Huddinge University Hospital in Stockholm show that eating with a blindfold decreased the intake of food, without making people feel less full. Eating blindfolded, therefore, may force us to rely more on internal signals.

Learning to recognise these internal, physiological cues of hunger and satisfaction will go a long way to controlling the amount that we eat. Just knowing that cravings and desires to eat come from external cues is really helpful. If you don't want to be always snacking, then don't have the snacks in the house. In the house is in the hand, in the hand is in the mouth.