Perception and hunger satisfaction

It seems our expectation about what we eat directly affects how hungry or satisfied we feel afterwards. In one study, when participants ate soup, not knowing that there was a hidden pump connected to their soup bowl which could surreptitiously alter the amount of soup available once eating started, their reported satiety related to how much soup they perceived  they had consumed and not the actual amount.

That experiment was adapted from one using fruit smoothies where participants were shown either a small or a large portion of fruit ‘used’ to make their smoothie. Their perception of satiety was directly linked to their perception of the quantity of fruit seen.

These findings, if reliable and valid, have real implications. When we consume a diet drink or food, or a reduced calorie or reduced sugar/fat food, does this affect how we feel afterwaards?  Do we feel hungry again much sooner because of our perception? If this is so, then using different descriptions might have a beneficial effect on those people who are trying to lose weight. One famous firm has for some time been marketing ‘hearty’ soups – this may have been a very smart move!