The law of diminishing satisfaction (getting sick of things), a core concept in economics, tells us that nearly everyone experiences drop in enjoyment with repeated consumption. Although people may find it particularly enjoyable when they initially start eating, the concept virtually guarantees that this enjoyment will be temporary. Thus, it should be easy to know when we are eating past the point when it is no longer pleasurable. However, the following factors show that our stomachs aren’t good at telling us when to stop eating (Wansink & Chandon, 2014). We tend to eat beyond subjective satiety. Being aware of these factors can help us eat less (Mann, 2015).
1. Food palatability
Eating is an important source of pleasure. Palatable food (tasty food) refers to those foods that have the capacity to stimulate the appetite and prompt us to eat more. They tend to be sugary, fatty, and salty. The better tasting the food, the more we will eat. Palatable foods can activate the reward circuits in the brain and tends to stimulate eating.
2. Portion size
Portion size matters. There is plenty of evidence that the larger the portion, the more you eat. The larger the plate size the more you may eat because of portions. When people are served a portion of food, they tend to assume that the portion size defines the reasonable meal amount to eat.
3. Food variety
Food variety increases appetites (Rolls, 1986). When people consume a variety of foods, they tend to overeat. Varied foods act as novel stimuli and slow the habituation process. This explains why do we always have room for dessert? The propensity to seek out and respond to food variety may be an evolutionarily advantageous phenomenon that may have arisen to ensure a balanced nutrient intake.
Distraction leads to overeating. Distractions cloud our mind and interfere with our ability to control our eating. A distractor (television, video games, talking to friends) serves to remove information about food stored in short-term memory, thus slowing down the rate of habituation. When we are mentally distracted, flavors taste less intense, so we may overeat to compensate for the mild flavor.
5. Stress eating
In general, sadness increases indulgent eating (Gardner et al, 2014). In a world where people often feel under stress, food is escape. Stress increases the reward value of palatable food because it stimulates opioid release, which decreases the stress response. Moreover, through repeated experiences, individuals may learn that eating comfort foods can reduce some of the unpleasant effects of stress.
Brian Wansink and Pierre Chandon. (2014) Slim by design: Redirecting the accidental drivers of mindless overeating. Journal of Consumer Psychology 24:3, 413-431.
Gardner, Meryl P., et al. (2014), Better moods for better eating?: How mood influences food choice. Journal of Consumer Psychology. Vol 24, issue 3, pages 320-335.
Rolls BJ. 1986. Sensory-specific satiety. Nutr Rev. 44:93–101